Radiometric Quantitation of PAIgG Stratified Treatment Response in ITP Patients.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3986-3986
Author(s):  
Dexter Estrada ◽  
Kenneth A. Schwartz2

Abstract Because treatment response in ITP is variable, it would be useful to be able to assess which patients are likely to respond to conventional treatment. Toward this goal we correlated the number of platelet surface IgG molecules measured with a quantitative radiometric platelet antibody assay (PAIgG) with treatment related changes in platelet count. We tested the hypothesis that patients’ response to conventional treatment could be stratified based on quantitation of the patients’ PAIgG. Data was obtained via a retrospective chart review. Patients with a diagnosis of idiopathic thrombocytopenic purpura (ITP), age 18 or older with an initial platelet count of <150,000, and quantitation of antiplatelet IgG performed at the time of diagnosis were included in the study. Patients were treated using conventional approaches that included steroids, IVIgG, anti-D antibody, splenectomy, and or cytotoxic medications. Patient response to therapy was evaluated as the change in platelet count, computed as the difference in platelet count obtained at diagnosis and the latest stable platelet count available. There were 64 patients with at least 90 days between initial and follow-up platelet counts. Of the 31 patients whose PAIgG were ≤1,000 molecules/platelet (m/plt), only 1 had an initial platelet count of <50,000. Of the 33 patients who’s PAIgG were >1,000 m/plt 16 had platelet counts of <50,000 (p≤0.001. Patients with PAIgG levels >1000 m/plt exhibited a significantly greater increase in platelet count μ=73,000 ±92,000 as compared to those with PAIgG levels ≤1000 m/plt, μ=18,000 ±43,000 (p=0.03). Although a PAIgG level of 500 m/plt is 3 standard deviations above the mean of normals, a greater response to treatment was noted in patients if their PAIgG level was >1000 m/plt. Patients with PAIgG levels between 500 and 1000 m/plt respond in a similar fashion to those with PAIgG levels <499. In addition, more patients with PAIgG levels >1000 m/plt received conventional treatment (19/33 vs. 10/31; p<0.05). In particular, there were more patients who received cytotoxic treatment in this cohort, (11/33 vs. 3/31; p≤0.025). Similar results were observed in 74 patients with at least 30 days between initial and follow-up platelet counts. This study suggests that measuring the amount of antiplatelet IgG stratifies ITP patients into 2 groups: patients with PAIgG ≤1,000 m/plt with platelet counts over 50,000 and patients with PAIgG >1,000 m/plt platelet counts that are less than 50,000. Those patients whose PAIgG is >1,000 m/plt are more likely to receive treatment and have an increase in platelet count with conventional therapy. We conclude that radiometric quantitation of PAIgG is helpful for predicting a patient’s response to therapy.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2352-2352
Author(s):  
Tomas Jose Gonzalez-Lopez ◽  
Fernando Fernandez-Fuertes ◽  
Maria Cristina Pascual Izquierdo ◽  
Isabel Caparros ◽  
Silvia Bernat ◽  
...  

Background: Successful discontinuation of eltrombopag in certain immune thrombocytopenia (ITP) patients after complete response has already been demonstrated. However, the frequency of this phenomenon and type of candidate patients are still matter of discussion. Moreover, possibility of long term discontinuation responses is not clearly established. Methods: Here we retrospectively evaluated our whole cohort of 508 adult patients (aged 18 years or more) with primary ITP treated with eltrombopag included in the Spanish Eltrombopag Registry with a focus on the patients who achieved a durable (at least six months) platelet response after stopping eltrombopag. Successful discontinuation of eltrombopag (SDOE) was defined as those patients who reached remission and maintained platelet counts ≥ 50x109/l for at least 6 months in absence of eltrombopag or any rescue therapies administered. Long term discontinuation of eltrombopag (LTDOE) was defined as those patients who reached remission and maintained platelet counts ≥ 50x109/l for at least 36 months in the absence of eltrombopag or any rescue therapies administered. The study was approved by the Hospital Universitario de Burgos Ethics Committee and fulfilled Helsinki declaration standards. Results: While 37.4% of our patients relapsed of ITP with subsequent platelet count drop sometime during first six months of discontinuation of eltrombopag, a total of 74 patients (14.6%) were able to achieve SDOE. The median age of SDOE patients was 62 [range, 47-79] years. There were 47 women and 27 men. According to the standard definition, patients were allocated to newly diagnosed (n=17), persistent (n=15) and chronic (n=42) ITP groups. The median time from diagnosis to eltrombopag initiation was 31 [range, 4-104] months. The median number of previous therapies was 2 [range, 1-2], including splenectomy (14%), rituximab (18%) and romiplostim (12%). As expected, all patients but 1 achieved a complete response (platelet count ≥100 x 109/L) prior to eltrombopag discontinuation The median duration of eltrombopag treatment was 7 [range, 2-19] months. Reasons for eltrombopag discontinuation were: persistent response despite a reduction in dose over time (n=43), platelet count >400x109/L (n=16), aspartate aminotransferase elevation (n=5), diarrhea (n=4), thrombosis (n=3), patient's request (n=2) and other reasons (n=1). Analysis of these SDOE discontinued patients show that with a median follow-up of 55 [range, 29-79] months, 38 patients (51.3%) maintained treatment-free response 36 months after stopping eltrombopag with no need of additional ITP therapies (median time of eltrombopag discontinuation was 70 [range, 50-77] months).This condition is what we define now as LTDOE. Nevertheless, 36 patients relapsed beyond 6 months but before 36 months of eltrombopag discontinuation (median time of eltrombopag discontinuation was 10 [range,7 -22] months). Characteristics of LTDOE population were a median time since ITP diagnosis of 32 [range, 5-88] months with 15/38 patients having ITP <1 year. 9 patients (24%) were male and their median age was 50 [range, 37-64] years. They had received a median of only two previous treatment lines [range: 1-2 lines]. The median platelet count before starting eltrombopag was 19 x 109/L [range, 8-40]. Meanwhile, platelet count before eltrombopag stop was 218 x 109/L [range, 123-356]. The main characteristics (age, gender, duration of ITP, prior ITP lines, platelet count before starting eltrombopag, duration of eltrombopag treatment, and platelet count before eltrombopag withdrawal) of the 38 patients with LTDOE were compared with those of the SDOE cohort who did not achieve a LTDOE. Unfortunately, no predictive factors of LTDOE could be identified. Conclusion: Durable platelet response following eltrombopag cessation may be observed in only 15% of primary ITP patients treated with this drug. On the contrary, half of patients who achieve a sustained response after eltrombopag withdrawal will get a long term discontinuation. However, we are lacking predictor factors for successful and long-term discontinuation of eltrombopag in primary ITP. Disclosures Gonzalez-Lopez: Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Pascual Izquierdo:Novartis: Consultancy; Sanofi: Consultancy. Sánchez-González:Amgen: Consultancy, Speakers Bureau; Gilead: Speakers Bureau; Navartis: Consultancy, Speakers Bureau; Shire: Speakers Bureau; Takeda: Consultancy, Speakers Bureau. Jarque:Takeda: Consultancy, Speakers Bureau; Shire: Consultancy, Speakers Bureau; Shionogi: Consultancy, Speakers Bureau; Servier: Speakers Bureau; Roche: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; MSD: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Grifols: Consultancy; Gilead: Consultancy, Speakers Bureau; CellTrion: Consultancy; Celgene: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Abbie: Consultancy, Speakers Bureau; Alexion: Consultancy, Speakers Bureau.


2020 ◽  
pp. 133-140
Author(s):  
Rei Ogawa

AbstractThe Vancouver scar scale, the Manchester scar scale, and the Patient and Observer Scar Assessment Scale (POSAS) are all very well-known scar evaluation methods. These tools are based on a number of scar variables, including color, height, and pliability. However, since all were mainly developed to evaluate burn scars, they are difficult to use in clinical practice for keloids and hypertrophic scars. This is because these pathological scars require both differential diagnosis and a way to evaluate their response to therapy. The Japan Scar Workshop (JSW) has sought to develop a scar assessment scale that meets these clinical needs. The first version of this scar assessment tool was named the JSW scar scale (JSS), and it was reported in 2011. In 2015, the revised second version was reported. The JSS consists of two tables. One is a scar classification table that is used to determine whether the scar is a normal mature scar, a hypertrophic scar, or a keloid. This grading system helps the user to select the most appropriate treatment method for the scar. The other table in the JSS is an evaluation table that is used to judge the response to treatment and for follow-up. Both tables contain sample images of each subjective keloid/hypertrophic scar item that allow the user to evaluate each item without hesitation.


2019 ◽  
Vol 36 (1) ◽  
pp. 25-31
Author(s):  
Danielle Mendelsohn ◽  
John R. Lewis ◽  
Kristin Iglesias Scott ◽  
Dorothy C. Brown ◽  
Alexander M. Reiter

The objectives of this study were to retrospectively describe clinicopathological features of eosinophilic oral disease in dogs, to identify possible risk factors or predispositions to the condition, and to report overall treatment response. Canine medical records from a veterinary teaching hospital and private referral practice over a 17-year period were reviewed for a diagnosis of eosinophilic oral disease. Twenty-four dogs with 26 lesions met the inclusion criteria. Patient mean age and body weight were 6.8 (3.8) years and 13.4 kg, respectively. Fifteen breeds were represented including Cavalier King Charles spaniel (16.7%), Labrador retriever (12.5%), and West Highland white terrier (12.5%). Eosinophilic lesions were found in the palate (65.4%), tongue (26.9%), and other oral locations (7.7%). Median follow-up time was 5 months. Analysis revealed statistically significant associations between lesion location and body weight (palatal and tongue lesions were more likely in smaller dogs, whereas lesions in the other category [lip or mucosa] were more likely in larger dogs). There was a correlation in lesion location and resolution (all dogs with palatal lesions became asymptomatic at their last recheck), and resolution and the use of antibiotics plus prednisone (greater likelihood of resolution without the use of this combination). Seventy percent of asymptomatic dogs resolved without medication or with allergen therapy alone, suggesting that asymptomatic dogs may respond well to conservative management. No associations were found between lesion location and breed, signalment and response to therapy, lesion resolution and the use of glucocorticoids, or significance of peripheral eosinophilia.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Nooshin Dalili ◽  
Pedram Ahmadpoor ◽  
Behzad Einollahi ◽  
Hamed Azhdari Tehrani

Abstract Background and Aims Renal transplantation is considered as the best replacement therapy for advanced ESRD patients. An allograft rejection happens as a result of post transplant immune reactions, which change the outcome of the organ transplantation. Today a major challenge in the field of transplantation is the identification of easy, reliable and non-invasive markers or methods that being able to predict the probability of organ rejection. One of the possible methods is looking for type of infiltrated cells in tissue obtaining by biopsy stained with specific cellular markers and assesses the infiltration of these cells in different types of rejection. Here the severity of CD3, CD20, Th17 and FOXP3 infiltration in patients with biopsy proven acute cellular rejection was evaluated based on IHC staining, whether these specific infiltrations can show an association with graft outcome or not. Method 50 patients with biopsy proven Acute T Cell Mediated Rejection (ATCMR) recruited. Previous clinical data and 1 year clinical follow up collected. The entire specimen assessed for infiltration of CD3, CD20, FOXP3 Tregs and Th17 with IHC. Patients divided into subgroups: stable graft function versus impaired graft function based on serum creatinine course in one year follow up after rejection therapy and appropriate response to treatment versus failure to response, based on allograft function throughout the course of admission. Results In impaired graft function arm, FOXP3 (7.88 vs. 8.02 with P-value 0.96) and Th17 cells were higher (5.01 vs. 10.2 with P-value 0.24) but with non-significant values. FOXP3/Th17 ratio was higher in stable group (1.4 vs. 1.12 with P-value 0.22). In failure to response to therapy group both FOXP3 (9.95 vs. 6.63 with P-value 0.1) and Th17 (11.3 vs. 8.3 with P-value 0.15) cells were higher. FOXP3/Th17 ratio was higher in proper response group (1.19 vs. 1.15 with P-value 0.8). No significant difference was obtained between CD3 and CD20 infiltration in these two groups. Conclusion Final results showed that Th17 has more important role in predicting the graft outcome and response to treatment and FOXP3 infiltration had a minor part. This may be in controversial with previous facts about the role of FOXP3 cells, which drive the allograft into stable condition.


2020 ◽  
Vol 91 (10) ◽  
pp. 1092-1099 ◽  
Author(s):  
Pietro Emiliano Doneddu ◽  
Dario Cocito ◽  
Fiore Manganelli ◽  
Raffaella Fazio ◽  
Chiara Briani ◽  
...  

ObjectivesTo determine the prevalence of different comorbidities in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and their impact on outcome, treatment choice and response.MethodsUsing a structured questionnaire, we collected information on comorbidities from 393 patients with CIDP fulfilling the European Federation of Neurological Societies and Peripheral Nerve Society criteria included in the Italian CIDP database.ResultsOne or more comorbidities were reported by 294 patients (75%) and potentially influenced treatment choice in 192 (49%) leading to a less frequent use of corticosteroids. Response to treatment did not differ, however, from that in patients without comorbidities. Diabetes (14%), monoclonal gammopathy of undetermined significance (MGUS) (12%) and other immune disorders (16%) were significantly more frequent in patients with CIDP than expected in the general European population. Patients with diabetes had higher disability scores, worse quality of life and a less frequent treatment response compared with patients without diabetes. Patients with IgG-IgA or IgM MGUS had an older age at CIDP onset while patients with other immune disorders had a younger age at onset and were more frequently females. IgM MGUS was more frequent in patients with motor CIDP than in patients with typical CIDP.ConclusionsComorbidities are frequent in patients with CIDP and in almost 50% of them have an impact on treatment choice. Diabetes, MGUS and other immune diseases are more frequent in patients with CIDP than in the general population. Only diabetes seems, however, to have an impact on disease severity and treatment response possibly reflecting in some patients a coexisting diabetic neuropathy.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4747-4747 ◽  
Author(s):  
Hans Hasselbalch

Abstract Background. Imatinib targets the ATP-binding sites of the protein tyrosine kinase domains associated with Bcr-abl, platelet-derived growth factor receptors (PDGFR) and c-kit. Most recently imatinib has been to inhibit autonomous erythropoiesis in vitro in polycythemia vera (PV)(1). Several clinical studies have indicated that imatinib may reduce phlebotomy requirements (2,3), but only a few patients have been followed for longer periods on imatinib monotherapy (2,3). Aim of the study. To evaluate the safety and efficacy of long term monotherapy with imatinib in PV. Patients.Eight patients (median age 60 years, range 39–68) have been treated. Five of the patients were enrolled in a phase II treatment protocol and three patients have been treated off protocol. None of the patients in the protocol had received cytotoxic treatment whereas the three patients treated off protocol had been treated with hydroxyurea (HU) and PEG-Intron. Imatinib was given at an initial dose of 400 mg/day in all patients. Methods. The diagnosis of PV was made according to conventional criteria, including an increased red cell blood volume and a low plasma erythropoietin. All patients were negative for the Bcr-abl transcript. A complete response (CR) was defined as phlebotomy-free within the first year of treatment, lasting at least 6 mo together with a platelet count less than 600 x 109/l and absence of splenomegaly. A partial response (PR) was defined by phlebotomy-free within the first year of treatment, lasting at least 6 mo together with a platelet count more than 600 x 109/l and a palpable spleen but less than 50 % of the original size (2). A minor response (MR) was defined as a reduction in the need of phlebotomies of at least 50 % but no change in the platelet counts. Results. Four patients have been followed for 12 mo on a dose of 400 mg daily apart from short periods, when the dose had to be decreased to 100 mg/day and 300mg/day, respectively, due to temporary side effects. Responses were seen in all evaluable patients (7/7) (CR=1; PR=6). The PR’s in two of the patients were obtained when HU (n=1) or PEG-Intron (n=1) were added. A definite decline in the Ht within the first month (&lt; 0.45) and a reduction in the need of phlebotomies were recorded in all evaluable patients whereas the leucocyte and platelet counts displayed a highly heterogeneous response pattern with unchanged and even rising platelet counts in 3 patients. The one patient with a CR displayed a reduction of spleen size and a decrease in the degree of bone marrow fibrosis after being treated for 12 mo. Almost complete alleviation of severe pruritus was noticed in one patient a few weeks after starting imatinib. One patient had to discontinue treatment after 1 week due to severe musculoskeletal pain. Otherwise the side effects were moderate and often transient. One of the patients noticed no side effects at all. Conclusions. Imatinib in PV is followed by a decrease in the Ht but highly heterogeneous leucocyte-and platelet responses in some patients when using 400 mg/day.Combinational therapy with HU or PEG-Intron seems safe and effective.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2232-2232 ◽  
Author(s):  
Geoffrey Dusheiko ◽  
Nezam H Afdhal ◽  
Edoardo Giannini ◽  
Pei-Jer Chen ◽  
Kwang-Hyub Han ◽  
...  

Abstract Abstract 2232 Introduction: Thrombocytopenia (TCP) is a common complication of cirrhosis in patients with hepatitis C virus (HCV) infections (Louie et al 2011); the presence of TCP impairs the ability to initiate peginterferon alpha (PEG) therapy and necessitates PEG dose reduction or discontinuation, thus reducing the potential for sustained virologic response (SVR). Eltrombopag, an oral, nonpeptide thrombopoietin receptor agonist approved for the treatment of chronic immune thrombocytopenia, increases platelet counts in patients with TCP due to HCV-related cirrhosis (McHutchison et al 2007). ENABLE 1 was a phase 3, multicenter, two-part study of eltrombopag for the treatment of HCV-associated TCP. Part 1 involved open-label, pre-antiviral treatment with eltrombopag. Patients achieving platelet counts ≥90,000/μL were randomized in Part 2 to receive eltrombopag or placebo in combination with antiviral therapy (PEG-2a plus ribavirin). Aim: To assess the safety and efficacy of eltrombopag during the open-label, pre-antiviral treatment phase (Part 1) of ENABLE 1 in patients with cirrhosis. Methods: Patients with chronic HCV and a baseline platelet count <75,000/μL were enrolled. In Part 1, all patients received open-label oral eltrombopag (25 mg daily with dose escalations every 2 weeks to a maximum dose of 100 mg) for up to 9 weeks or until platelet counts reached ≥90,000/μL. Patients who failed to achieve platelet counts ≥90,000/μL following 3 weeks of eltrombopag 100 mg daily did not enter Part 2 and attended scheduled follow-up visits. Patients achieving these counts were randomized 2:1 to eltrombopag or placebo (Part 2) at the final dose received in Part 1, in combination with antiviral therapy for up to 48 weeks. Results: A total of 716 patients were enrolled; 1 patient withdrew due to a protocol deviation, and 715 entered the open-label pre-antiviral phase. At study entry, most patients were male (62%) and Caucasian (72%); 17% were of Japanese/East Asian heritage. The median age was 52 years (range, 19–76). 488 patients (68%) had cirrhosis (FibroSURE™ score equivalent to METAVIR F4). The median duration of treatment during Part 1 was 20 days and the median of the mean daily dose was 25 mg (range, 0.8–75 mg). Median baseline platelets were 59,000/μL; these increased to 89,000/μL by week 2 and remained consistently elevated throughout open-label treatment (Figure). Following a median of 2 weeks of treatment (range, 0.1–9.6 weeks), 691 patients (97%) achieved platelet counts ≥90,000/μL. Treatment was discontinued during Part 1 for 33 patients (5%): platelets <90,000/μL (11); adverse events (AEs, 9); investigator discretion (7); patient decision (3); loss of follow-up (2); or a protocol deviation (1). During Part 2, 682 patients (95%) were randomized, 2 patients withdrew consent following randomization, and 680 patients (95%) initiated antiviral treatment. Of the patients who initiated treatment, 451 (66%) did so within 2 weeks and 627 (92%) did so within 4 weeks. The most common AEs observed during the open-label treatment phase were headache (7%), fatigue (4%), nausea (3%), and diarrhea (3%). Ninety-five patients (13%) experienced platelet counts >200,000/μL. No thromboembolic events were observed during open-label treatment. Conclusions: Eltrombopag was generally well-tolerated and resulted in sustained increase in platelet counts during the open-label, pre-antiviral treatment phase. Platelet count increases were seen as early as 2 weeks following initiation of treatment. The vast majority of patients (97%) achieved platelet count increases to ≥90,000/μL, the threshold for initiating PEG-2a plus ribavirin therapy, and most did so within 4 weeks of initiating eltrombopag treatment. Disclosures: Dusheiko: GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding. Off Label Use: Eltrombopag, inteferon and Ribavirin; eltrombopag is a thrombopoetin receptor agonist. Its efficacy and safety in raising platelet counts in hepatitis C positive patients (most with cirrhosis) and thrombocyotopaenia was studied in this protocol. Afdhal:Merck: Consultancy, Honoraria, Research Funding; Vertex: Consultancy, Honoraria, Research Funding; Idenix: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Springbank: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Pharmasett: Consultancy, Honoraria, Research Funding; Abbott: Consultancy, Honoraria, Research Funding. Giannini:GlaxoSmithKline: Consultancy, Speakers Bureau; Hoffman-LaRoche: Consultancy, Speakers Bureau. Chen:Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mostafa Kamel:GlaxoSmithKline: Employment, Equity Ownership. Brainsky:GlaxoSmithKline: Employment, Equity Ownership. Geib:GlaxoSmithKline: Employment. Vasey:GlaxoSmithKline: Employment. Patwardhan:GlaxoSmithKline: Employment, company shares. Campbell:GlaxoSmithKline: Employment, Equity Ownership. Theodore:GlaxoSmithKline: Employment, Equity Ownership, Patents & Royalties.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3289-3289
Author(s):  
Jianlin Qiao ◽  
Huy Tran ◽  
Fi-Tjen Mu ◽  
Robert K Andrews ◽  
Elizabeth E Gardiner

Abstract Abstract 3289 In this study we assess platelet receptor expression and shedding in patients with immune thrombocytopenia (ITP) before and during treatment. The aim is to evaluate the potential value of quantitative measurement of platelet receptors for diagnosis and/or monitoring treatment in thrombocytopenia due to immune or other causes. The platelet-specific collagen receptor, glycoprotein (GP)VI, is associated with the Fc receptor γ-chain (FcRγ). GPVI/FcRγ is coassociated on platelet surface with the GPIb-IX-V complex; GPIbα of GPIb-IX-V binds von Willebrand factor and other ligands. Our previous studies showed engagement of platelet FcγRIIa by antiplatelet antibodies induced ectodomain shedding of GPVI, generating soluble ectodomain (sGPVI) in plasma. However, apart from one individual with an anti-GPVI antibody, whether anti-platelet antibodies associated with ITP affect GPVI/GPIb expression/shedding has not been addressed. In this study we used flow cytometry and a sGPVI ELISA to assess 1) whether patients with ITP had dysregulated expression/shedding of GPVI or GPIbα, and 2) whether platelet receptor expression changes prior to recovery of platelet count in individuals undergoing treatment for ITP. In 9 ITP patients (mean age=48.6, range 29–79; 6 female) with platelet count 61±9 × 109/L (range, 33–122 × 109/L), GPVI surface expression (GeoMean±SE, 137±17) was lower than healthy controls (274±26; n=17; platelet count 247±13), and sGPVI in patient plasma was significantly higher (39±4 ng/mL) compared to 17 healthy donors (19±3 ng/mL) (P=0.0006). In longitudinal samples analysed at weekly intervals during 2-month treatment with steroids, decreased GPVI surface expression and increased sGPVI in plasma remained essentially unchanged as the platelet count normalized, consistent with persistent anti-platelet antibody. However, while levels of intact platelet GPIbα were significantly reduced in ITP compared to healthy donors (P=0.0053), they approached healthy levels within 1 week of treatment, preceding improvement in platelet count or other measures. GPIbα expression/cleavage has been previously implicated in platelet clearance in experimental models, and our analysis suggests the proteolytic status of human GPIbα may be a novel early marker for evaluating response to treatment in ITP. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3288-3288 ◽  
Author(s):  
Robert Makar ◽  
Olga S. Zhukov ◽  
Mervyn A. Sahud ◽  
David J. Kuter

Abstract Abstract 3288 INTRODUCTION: Thrombopoietin (TPO) is the major regulator of platelet production. In prior clinical studies, thrombopoietin levels have been shown to vary inversely with circulating platelet mass and with the rate of platelet production. Thus, TPO levels may help distinguish between the various disorders of thrombocytopenia. In addition, the introduction of TPO agonists has created an interest in predicting the response of patients to these agents. Determining TPO levels may help predict such treatment responses. METHODS: Sera from 121 patients with a history of abnormal platelet counts were tested using a novel, commercially available ELISA assay that measures TPO levels. The TPO assay detected TPO levels as low as 7 pg/mL and was linear for levels up to 2000 pg/mL. The coefficient of variation ranged from 27% near the lower limit of detection to 9% at a TPO concentration of 669 pg/mL. The reference range for TPO was established in serum samples from 118 apparently healthy individuals (58 males and 60 females) and was 7–99 pg/mL. The Wilcoxon test was used to compare continuous variables and the Fisher's exact test was used to compare categorical variables. RESULTS: The patient population included 40 patients with a consumptive thrombocytopenia (38 with primary or secondary immune thrombocytopenic purpura (ITP), 2 with thrombotic thrombocytopenic purpura), 34 patients with myeloproliferative disorders (23 with essential thrombocytosis, 9 with polycythemia vera, 2 with an ill-defined myeloproliferative disorder), and 47 patients with hypoproliferative thrombocytopenia (29 with chemotherapy-related thrombocytopenia, 19 with primary or secondary bone marrow failure syndromes). Among the 38 patients with ITP, 11 were taking TPO agonists (9 on romiplostim, 2 on eltrombopag), 19 were taking immunomodulatory agents (16 on steroids alone or in combination with other therapies, 2 on azathioprine, 1 on danazol), and 12 were off ITP-specific therapy when the TPO level was measured. 9 out of 38 (24%) patients with ITP had undergone splenectomy and/or been previously treated with rituximab. The median serum TPO level in patients with consumptive thrombocytopenia was 64.5 pg/mL (interquartile range, 48.5–97.5 pg/mL) and the corresponding median platelet count was 68,000/μL (interquartile range, 27,000–144,500) (Figure). While patients with myeloproliferative disorders had similar TPO levels [median 87.0 pg/mL (38.0–125.5)], their platelet counts were significantly higher than those of patients with consumptive thrombocytopenia [median 549,500/mL (431,250–693,000] (P <0.0001). Contrastingly, comparable platelet counts [median 61,000/μL (31,000–118,000)] were observed among patients with hypoproliferative thrombocytopenia, but serum TPO levels were significantly higher than those of patients with consumptive thrombocytopenia [844 pg/mL (409.5–1551.5), P <0.0001]. Among 22 evaluable patients meeting diagnostic criteria for primary or secondary ITP who had taken a TPO agonist for at least 1 month, serum TPO levels appeared to predict responsiveness to the drug. A clinical response to a TPO agonist was defined as achieving a platelet count ≥50,000/μL after starting the drug and maintaining it at or above that count in ≥50% of subsequent complete blood counts from initiation until discontinuation of the drug, loss to follow-up, or 6 months had passed, whichever was longest, without the need for recurrent rescue therapy. Whereas 14 out of 16 (88%) ITP patients with a TPO level <99 pg/mL met our definition for a clinical response to treatment with a TPO agonist, only 1 out of 6 patients (17%) with a TPO level >99 pg/mL responded (P <0.005 for the difference in clinical response to TPO agents.) CONCLUSIONS: TPO levels may have diagnostic utility in discriminating between patients with hypoproliferative and consumptive thrombocytopenia. High TPO levels among patients with ITP may predict a poor clinical response to treatment with TPO agonists. Further studies are required to confirm these data. Disclosures: Zhukov: Quest Diagnostics: Employment. Sahud:Quest Diagnostics: Employment. Kuter:Quest Diagnostics: Consultancy, Research Funding.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3534-3534
Author(s):  
Andrew L. Frelinger ◽  
Anja J Gerrits ◽  
Michelle A. Berny-Lang ◽  
Travis Brown ◽  
Sabrina L. Carmichael ◽  
...  

Abstract Background Immune thrombocytopenia (ITP) patients with similarly low platelet counts differ in their tendency to bleed. Aim To determine if differences in platelet function in ITP patients with similarly low platelet counts partly account for the variation in bleeding tendency. Methods The relationship between bleeding scores and platelet function markers was investigated in a single center cross-sectional study of pediatric patients with ITP. Following informed consent, blood was collected from ITP patients and bleeding was graded using the Buchanan and Adix Score (J Pediatr 2002) at routine clinic visits or while admitted to the hospital. Bleeding scores were obtained by one of three hematologists blinded to platelet function results, and investigators performing platelet function tests were blinded to clinical results. Platelet function was assessed by whole blood flow cytometric measurement of unstimulated, ADP- or TRAP-stimulated platelet surface activated GPIIb-IIIa (as measured by PAC1 binding), P-selectin, and GPIb and by unstimulated, convulxin-, or ADP plus TRAP-stimulated platelet surface phosphatidylserine expression (as determined by annexin V binding). Platelet count, immature platelet fraction (IPF) and mean platelet volume (MPV) were determined by a Sysmex XE-2100, and platelet forward angle light scatter (FSC) was measured by flow cytometry. Results Platelet function and bleeding scores were evaluated in 34 consecutive consenting pediatric ITP patients (16 female, 18 male, age 9.7 ± 5.7 years [mean ± SD]). ITP was newly diagnosed (< 3 months) in 10 patients, persistent (3 -- 12 months) in 7 patients, and chronic (>12 months) in 17 patients. Platelet count at the time of the blood draw was 47 ± 55 x 109/L. The median bleeding score on day of blood draw was 1 (range 0 to 4). By univariate analysis, higher IPF, and lower platelet count were significantly associated with a higher bleeding score (odds ratio [OR] >1, p<0.05) but MPV was not. Multiple measures of platelet function were associated with bleeding scores by univariate analysis: higher levels of platelet FSC (a measure affected by multiple variables including size) surface GPIb on unstimulated, ADP- or TRAP-stimulated platelets, surface P-selectin on unstimulated platelets, and platelet FSC were associated with increased odds for higher bleeding scores (ORs each >1, p<0.05), while higher ADP- and TRAP-stimulated platelet surface activated GPIIb-IIIa and P-selectin were associated with reduced odds of higher bleeding scores (ORs each <1, p<0.05). After adjustment for platelet count, higher levels of platelet surface P-selectin on unstimulated platelets, GPIb on TRAP-stimulated platelets, and FSC remained significantly associated with increased odds for higher bleeding scores (Figure), but IPF did not. Similarly, after adjustment for platelet count, higher TRAP-stimulated percentage of P-selectin and activated GPIIb-IIIa positive platelets remained significantly associated with reduced odds of higher bleeding scores (Figure). These findings were independent of recent ITP-related treatment. Conclusions In this study of pediatric ITP patients, we identified selected platelet function markers which, independent of platelet count, are associated with increased (platelet FSC, platelet surface P-selectin on unstimulated platelets, and GPIb on TRAP-stimulated platelets) or decreased (TRAP-stimulated percent P-selectin and GPIIb-IIIa positive platelets) odds of high bleeding scores. Possible hypotheses to explain these associations are as follows: 1) Increased P-selectin on unstimulated platelets demonstrates in vivo platelet activation, possibly as a consequence of the recent bleeding. 2) Because platelet activation results in a reduction in platelet surface GPIb and increases in platelet surface activated GPIIb-IIIa and P-selectin, the ORs associated with all of these markers could be explained by reduced ability of platelets in patients with higher bleeding scores to respond to agonists. 3) While platelet FSC is partly related to size, the finding that MPV and IPF, adjusted for platelet count, were not associated with bleeding score suggests that factors other than size account for the association of platelet FSC with higher bleeding scores. Further study is required to validate these findings and determine if differences in platelet function are associated with future risk for bleeding. Disclosures: Off Label Use: Eltrombopag was given to WAS/XLT patients for treatment of thrombocytopenia. Neufeld:Shire: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Apopharma: Consultancy. Michelson:Sysmex: Honoraria.


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