scholarly journals Thrombocytopenia: diagnosis with flow cytometry and antiplatelet antibodies

2011 ◽  
Vol 9 (2) ◽  
pp. 130-134
Author(s):  
João Carlos de Campos Guerra ◽  
Ruth Hissae Kanayama ◽  
Sonia Tsukasa Nozawa ◽  
Márcia Regina Ioshida ◽  
Irina Yoko Takiri ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Hepatitis C ◽  
Hiv Infection ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Direct Method ◽  
Thrombocytopenic Purpura ◽  
Platelet Counts ◽  
Antiplatelet Antibodies ◽  
Normal Platelet ◽  
Platelet Autoantibodies

Objective: To identify antiplatelet antibodies by flow cytometry (direct method) in patients with thrombocytopenia. Methods: Between January 1997 and March 2004 a total of 15100 patients were referred to the Centro de Hematologia de São Paulo for hematological investigation of several diagnoses (anemia, leukopenia, thrombocytopenia, coagulation abnormalities, adenomegaly, leukemia and others). Of those, 1057 were referred because of thrombocytopenia and were divided into two groups: Group Idiopathic thrombocytopenic purpura, with no identifiable cause; and Group Other thrombocytopenia, which included low normal platelet counts cause to be established, hepatitis C and HIV infection, hypersplenism, EDTA-induced artifacts, laboratory error, and other causes. Flow cytometry immunophenotyping was done in 115 cases to identify platelet autoantibodies (direct method). Results: Of the total number of patients, 1057 (7%) presented low platelet counts, 670 were females (63.4%) and age range of one to 75 years. Of the 115 cases (9.7%) submitted to immunophenotyping, the results were positive in 40% and the test was inconclusive in 5%. Idiopathic thrombocytopenic purpura was found in 52% of patients, more often in women. Hepatitis C virus infection was found in 7% and HIV infection in 1%. Low normal platelet counts were found in 17%, laboratory errors in 6%, and laboratory artifacts in 1% of cases. Platelet autoantibodies were found in 76.9% of all idiopathic thrombocytopenic purpura cases. It was negative in 83.3% of the low normal counts. Conclusion: antiplatelet autoantibodies when present help to diagnose idiopathic thrombocytopenic purpura. When absent, suggest other causes of thrombocytopenia.

scholarly journals Microscopic platelet size and morphology in various hematologic disorders

Blood ◽  
1978 ◽  
Vol 51 (3) ◽  
pp. 479-486
Author(s):  
Z Zeigler ◽  
S Murphy ◽  
FH Gardner
Keyword(s):  
Idiopathic Thrombocytopenic Purpura ◽  
Lupus Erythematosus ◽  
Thrombocytopenic Purpura ◽  
Hematologic Disorders ◽  
Platelet Counts ◽  
Normal Platelet ◽  
Large Size ◽  
Platelet Size ◽  
Microscopic Evaluation ◽  
Size And Morphology

Microscopic evaluation of apparent platelet size and morphology was examined in a variety of hematologic disorders. The time of preparation of the blood smear was important. An artifactual increase in platelet size was noted on blood films from 20 normal individuals that were prepared either immediately or 180 min after venipuncture. The clearest differentiation of patient categories was obtained with smears prepared 60 min after venipuncture using blood anticoagulated with K3EDTA. Under these conditions, normal size and morphology values were found in thrombocytopenic patients with aplasia or with increased splenic pooling. In contrast, large size values were a reliable finding in idiopathic thrombocytopenic purpura patients, whose platelet counts were less than 50,000/microleter. Large size values were also noted in patients with infiltrated bone marrows or myeloproliferative syndromes regardless of the platelet count. The last two groups usually showed abnormal platelet morphology with greater than 10% hypogranular platelets. Normal platelet size and morphology were observed in patients with iron-deficiency and megaloblastic anemias and in patients with idiopathic thrombocytopenic purpura and systemic lupus erythematosus who had normal platelet counts.

scholarly journals Microscopic platelet size and morphology in various hematologic disorders

Blood ◽  
1978 ◽  
Vol 51 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Z Zeigler ◽  
S Murphy ◽  
FH Gardner
Keyword(s):  
Idiopathic Thrombocytopenic Purpura ◽  
Lupus Erythematosus ◽  
Thrombocytopenic Purpura ◽  
Hematologic Disorders ◽  
Platelet Counts ◽  
Normal Platelet ◽  
Large Size ◽  
Platelet Size ◽  
Microscopic Evaluation ◽  
Size And Morphology

Abstract Microscopic evaluation of apparent platelet size and morphology was examined in a variety of hematologic disorders. The time of preparation of the blood smear was important. An artifactual increase in platelet size was noted on blood films from 20 normal individuals that were prepared either immediately or 180 min after venipuncture. The clearest differentiation of patient categories was obtained with smears prepared 60 min after venipuncture using blood anticoagulated with K3EDTA. Under these conditions, normal size and morphology values were found in thrombocytopenic patients with aplasia or with increased splenic pooling. In contrast, large size values were a reliable finding in idiopathic thrombocytopenic purpura patients, whose platelet counts were less than 50,000/microleter. Large size values were also noted in patients with infiltrated bone marrows or myeloproliferative syndromes regardless of the platelet count. The last two groups usually showed abnormal platelet morphology with greater than 10% hypogranular platelets. Normal platelet size and morphology were observed in patients with iron-deficiency and megaloblastic anemias and in patients with idiopathic thrombocytopenic purpura and systemic lupus erythematosus who had normal platelet counts.

scholarly journals (NZW x BXSB)F1 mouse. A new animal model of idiopathic thrombocytopenic purpura.

1988 ◽  
Vol 167 (6) ◽  
pp. 2017-2022 ◽  
Author(s):  
N Oyaizu ◽  
R Yasumizu ◽  
M Miyama-Inaba ◽  
S Nomura ◽  
H Yoshida ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Animal Model ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Bone Marrow Cells ◽  
Normal Bone Marrow ◽  
Thrombocytopenic Purpura ◽  
Thrombocyte Count ◽  
Normal Bone ◽  
Antiplatelet Antibodies ◽  
Normal Platelet

A decrease in thrombocyte count was observed in (NZW x BXSB)F1 (W/B F1) mice at the age of greater than 5 mo, whereas megakaryocyte counts were found to increase in such mice. FACS analyses revealed the presence of both platelet-associated antibodies (PAA) and circulating antiplatelet antibodies. There is a correlation between the presence of these antibodies and the degree of thrombocytopenia. The transplantation of normal bone marrow cells from BALB/c nu/nu mice to W/B F1 mice was found to have preventative and curative effects on thrombocytopenia; the mice showed normal platelet counts and no evidence of circulating antiplatelet antibodies. These results indicate that thrombocytopenia in W/B F1 mice is due to the presence of antibodies to platelets. We therefore think that W/B F1 mice serve as a useful animal model of idiopathic thrombocytopenic purpura (ITP) not only for elucidating the mechanism of the development of antiplatelet antibodies, but also for characterizing autoantibodies to platelets.

Platelet Counts Remain Elevated in Two Patients with Idiopathic Thrombocytopenic Purpura after Cessation of Oral Eltrombopag.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3927-3927 ◽  
Author(s):  
Gregory Cheng
Keyword(s):  
Idiopathic Thrombocytopenic Purpura ◽  
Platelet Destruction ◽  
Double Blind ◽  
Thrombocytopenic Purpura ◽  
Platelet Counts ◽  
Normal Platelet ◽  
Baseline Levels ◽  
Platelet Growth Factor ◽  
Dose Dependent Increase ◽  
Dose Dependent

Abstract Idiopathic thrombocytopenic purpura (ITP) is a disease of inadequate platelet production and increased platelet destruction. Two randomized, double-blind, placebo-controlled trials (TRA100773 A/B) reported that eltrombopag, the first-in-class, oral, platelet growth factor, results in a dose-dependent increase in platelet counts in adult patients with chronic ITP. After treatment of eltrombopag was stopped, platelet counts returned to baseline levels in most patients within 2 weeks, reflecting the normal platelet lifespan (range, 10–14 days). This abstract presents data on two patients enrolled in TRA100773 A/B in whom a prolonged platelet count elevation was observed after cessation of eltrombopag treatment. A 79-year old Asian female (Patient 1) was diagnosed with ITP in September 2003. Prior ITP therapy included prednisolone and Danazol simultaneously in 1997. Prednisolone was stopped after 10 months. Danazol was continued until March 2005 (Day -50). The patient relapsed in March 2005 and received dexamethasone (5 days), IVIg (once), vincristine, and cyclosporin A without a significant response. Eltrombopag treatment was started in May 2005 leading to an increase in platelet counts that remained elevated above 100,000/uL after treatment with eltrombopag was discontinued (Table). Patient 2, a 49-year old Asian female, was diagnosed with ITP in 1997. She relapsed after two courses of dexmethasone 40 mg, QD × 4, administered in September 2003 with a 3-month response and in January 2006 with a 1-month response. Therapy with eltrombopag was initiated in March 2006. As was seen with Patient 1, platelet counts increased after administration of eltrombopag and remained elevated after cessation of eltrombopag (Table). To the best of our knowledge, this is the first report of an ongoing prolonged elevation of platelet counts after cessation of thrombopoietic medication, such as eltrombopag. Platelet Counts (/uL) Patient 1 Patient 2 *Eltrombpag withdrawn in both patients. Screening 26,000 69,000 Day 1 26,000 26,000 Day 8 193,000 136,000 Day 15* 591,000 283,000 Day 22 664,000 --- Day 50 --- 260,000 Day 57 330,000 116,000 Day 71 112,000 100,000 Day 85 116,000 111,000

PAICA: A Method for Characterizing Platelet-Associated Antibodies - Its Application to the Study of Idiopathic Thrombocytopenic Purpura and to the Detection of Platelet-bound c7E3

1996 ◽  
Vol 76 (06) ◽  
pp. 1020-1029 ◽  
Author(s):  
Laurent Macchi ◽  
Gisèle Clofent-Sanchez ◽  
Gérald Marit ◽  
Claude Bihour ◽  
Catherine Durrieu-Jais ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Flow Cytometry ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Antithrombotic Therapy ◽  
Membrane Glycoproteins ◽  
Serum Antibodies ◽  
Platelet Destruction ◽  
Thrombocytopenic Purpura ◽  
Capture Assay ◽  
Specific Membrane

SummaryIn idiopathic thrombocytopenic purpura (ITP), autoantibodies reacting with antigens on the platelet membrane bring about accelerated platelet destruction. We now report PAICA (“Platelet-Associated IgG Characterization Assay”), a method for detecting autoantibodies bound to specific membrane glycoproteins in total platelet lysates. This monoclonal antibody (MAb) capture assay takes into account the fact that antibodies on circulating platelets may be translocated to internal pools as well as being on the surface. A total of twenty ITP patients were examined by PAICA, and the results compared with those obtained by measuring (i) serum antibodies bound to paraformaldehyde-fixed control platelets by ELISA, (ii) IgG bound to the surface of the patient’s own platelets by flow cytometry (PSIgG), (iii) total platelet-associated IgG (PAIgG) by ELISA and (iv) serum antibodies reacting with control platelets by MAIPA (“Monoclonal Antibody-specific Immobilization of Platelet Antigens”). Of twelve patients with elevated PAIgG, nine had increased PSIgG yet eleven reacted positively in PAICA. Of these, eight possessed antibodies directed against GP Ilb-IIIa, two against GP Ib-IX and one patient possessed antibodies directed against GP Ilb-IIIa and GP Ia-IIa respectively. Only seven of the patients possessed serum antibodies detectable by MAIPA. PAICA was also able to detect platelet-associated c7E3 (the chimeric form of Fab fragments of the MAb 7E3) following its infusion during antithrombotic therapy, when it proved more sensitive over a seven-day period than a MAIPA assay adapted for assessing surface-bound antibody. We propose that PAICA provides added sensitivity to the detection of platelet-associated antibodies in immune thrombocytopenias or following therapy with humanized MAbs.

scholarly journals Subarachnoid Haemorrhage Complicating Resistant Idiopathic Thrombocytopenic Purpura: A Case Report

2014 ◽  
Vol 4 (2) ◽  
pp. 105-107
Author(s):  
Farhana Afroz ◽  
Hasna Fahmima Haque ◽  
Samira Rahat Afroze ◽  
Muhammad Abdur Rahim ◽  
Aparna Rahman ◽  
...  
Keyword(s):  
Case Report ◽  
Autoimmune Disease ◽  
Subarachnoid Haemorrhage ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Conservative Management ◽  
Thrombocytopenic Purpura ◽  
Platelet Counts ◽  
Chronic Itp

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease where low platelet counts predisposeto various bleeding tendencies; intracranial haemorrhageis one of them. It is a rare and devastating complication of ITP, mostly presenting as intracerebral (ICH) or subarachnoid haemorrhage (SAH). Here, we report a 32-year-old splenectomized chronic ITP patient on corticosteroid and azathioprine, in whom spontaneous SAH developed. In this case, conservative management resulted in clinicoradiological improvement and showed eventual favourable out-come.Birdem Med J 2014; 4(2): 105-107

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