Identification of novel mutations in ADAMTS13 in an adult patient with congenital thrombotic thrombocytopenic purpura

Blood ◽  
2004 ◽  
Vol 104 (7) ◽  
pp. 2081-2083 ◽  
Author(s):  
Toshihiro Uchida ◽  
Hideo Wada ◽  
Minoru Mizutani ◽  
Miho Iwashita ◽  
Hiroaki Ishihara ◽  
...  

Abstract Congenital thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) is associated with an inherited von Willebrand factor-cleaving protease (ADAMTS13 [a disintegrin and metalloprotease with thrombospondin type I domains 13]) deficiency. In this study, we identified novel mutations in the ADAMTS13 gene in a patient with TTP. The patient was a 51-year-old Japanese male who exhibited TTP symptoms at frequent intervals. The ADAMTS13 activity during acute episodes was less than 3% that of normal. The enzyme activities of the patient's father and mother were both 46%, and both parents were asymptomatic. Genetic analysis revealed that the patient was a compound heterozygote for 2 mutations. One mutation was a missense mutation in the metalloprotease domain (A250V, exon 7), and the other was a guanine to adenine substitution at the 5′ end of intron 3 (intron 3 G→A). In vitro expression studies revealed that the A250V mutation markedly reduced ADAMTS13 activity and the intron 3 G→A mutation caused abnormal mRNA synthesis. (Blood. 2004;104: 2081-2083)

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5005-5005
Author(s):  
Xia Bai ◽  
JIan Su ◽  
Lijuan Cao ◽  
Changgeng Ruan

Abstract Introduction: Congenital thrombotic thrombocytopenic purpura (TTP) is characterized by disseminated thrombus due to the mutations of ADAMTS13, which cleaves its substrate von Willebrand factor(VWF) in shear-induced unfolding condition. Most of the congenital TTP we found is woman with pregnancy. Here, we characterize two children suspected with congenital TTP. Methods:ADAMTS13 activities were analyzed by residual collagen binding assay (R-CBA) plus FRET-VWF substrate. And the inhibitors of ADAMTS13 were analyzed by 9:1 mixture of patient and pooled normal plasma followed by R-CBA. The secretion of recombinant ADAMTS13 mutants was studied. Results: Two children, one aged four months and the other aged three years old, were diagnosed with congenital TTP because their ADAMTS13 activities were less than 5% (both FRET-VWF and R-CBA), and there are short of ADAMTS13 inhibitors. The following mutations were found: Q1385P, Y177C, C522R. In addition to the previously reported mutation of Y177C, the two novel mutations (Q1385P and C522R) failed to secrete from the HEK293 cells. Conclusion: Two children with congenital TTP were determined thanks to screening of ADAMTS13 activity and its corresponding inhibitor assays, and it seems that congenital TTP could occur in different ages although most of congenital TTP we found were women with pregnancy. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2005 ◽  
Vol 105 (2) ◽  
pp. 542-544 ◽  
Author(s):  
Jan-Dirk Studt ◽  
Johanna A. Kremer Hovinga ◽  
Gerhard Antoine ◽  
Martin Hermann ◽  
Manfred Rieger ◽  
...  

AbstractSevere ADAMTS13 deficiency in thrombotic thrombocytopenic purpura (TTP) is either constitutional and caused by ADAMTS13 mutations, or acquired and most often due to ADAMTS13 inhibitory autoantibodies. In strongly hemolytic serum of a pediatric patient, diagnosed with TTP postmortem, ADAMTS13 activity was less than 3%. Both parents had an ADAMTS13 activity of approximately 50%. Sequencing of the ADAMTS13 gene revealed an intronic 687-2A>G substitution affecting exon 7, homozygous in the propositus and heterozygous in both parents, confirming constitutional ADAMTS13 deficiency. ADAMTS13 activity of normal plasma was inhibited by incubation with the propositus' serum, suggesting alloantibody formation to ADAMTS13. However, immunoglobulin purified from serum had no ADAMTS13 inhibitory effect, whereas the immunoglobulin-depleted hemolytic serum inhibited ADAMTS13 activity of normal plasma, suggesting an inhibitory effect of hemolysis products. Incubation of hemoglobin, recombinant and from lysed erythrocytes, with normal plasma revealed an ADAMTS13 inhibitory effect at hemoglobin concentrations of 2 g/L or higher.


2021 ◽  
Vol 29 (3) ◽  
pp. 270-273
Author(s):  
Başak Ergin ◽  
Berna Buse Kobal ◽  
Zeynep Yazıcı ◽  
Ali Hakan Kaya ◽  
Sezin Canbek ◽  
...  

Objective Thrombotic thrombocytopenic purpura is a thrombotic microangiopathic condition characterized by hemolytic anemia, thrombocytopenia, neurologic abnormalities, fever and renal dysfunction. Thrombotic microangiopathies such as preeclampsia and HELLP syndrome are pregnancy-specific, whereas others such as thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome are not. In this report, we present a case at which we identified a novel mutation which led to a significant reduction of ADAMTS13 activity. Case(s) A nulliparous pregnant woman of 32-year-old presenting with epigastric pain, hypertension and low platelet count was first suspected of HELLP syndrome, but was diagnosed with congenital TTP after delivery. Conclusion HELLP syndrome co-existed with undiagnosed TTP in this case. We strive to have sufficient awareness in order to distinguish these two pathologies from each other on an antenatal basis, because the causes of the managements are entirely different.


2013 ◽  
Vol 61 (3) ◽  
pp. 558-561 ◽  
Author(s):  
Ayse Metin ◽  
Sule Unal ◽  
Fatma Gümrük ◽  
Roberta Palla ◽  
Andrea Cairo ◽  
...  

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4661-4661
Author(s):  
Sarah Steinemann ◽  
Tanja Falter ◽  
Mirjeta Qorraj ◽  
Thomas Vigh ◽  
Inge Scharrer

Abstract Abstract 4661 Introduction: Thrombotic thrombocytopenic purpura (TTP) is characterized by thrombocytopenia, hemolytic anemia and microthrombi. A deficiency of the metalloprotease ADAMTS 13, which cleaves a Tys1605-Met1606 bond in the A2 subunit of von Willebrand factor (VWF), leads to formation of ultra large von Willebrand multimers (UL-VWF) and can cause platelet aggregation and mircovascular thrombosis. Treatment of choice is the substitution of plasma with plasmaexchange. There are two different plasma types available: Fresh Frozen Plasma (FFP) and solvent/detergent (s/d) treated plasma. This treatment may carry significant risks and side effects for the patients. Therefore we investigated the side effects of the therapy and furthermore the ADAMTS13 activity of the two plasma types. Methods: A questionnaire was send to 66 TTP patients of the Department of Hematology to evaluate different side effects of the therapy. 20 batches of FFP and 4 batches of s/d plasma of all blood groups were investigated on ADAMTS13 activity. The ADAMTS13 activity was detected with BCS-Method according to Böhm and two commercial FRET assays. Results: So far 34 patients were inquired about age, weight and suspected trigger situations that might have caused their TTP manifestation. The mean age of the patients was 34 years with a mean weight of 70kg. A previous infection caused TTP manifestation in 42% of the patients; drug therapy (22%) and pregnancy (17%) were other mentioned triggers. 94% of the patients suffered from an acquired TTP and only 6% had a hereditary TTP. The patients had 2.88 relapses and were treated with 16.27 plasmaexchanges. 56% had an additional therapy with Rituximab to achieve a faster remission of the disease. These patients needed less plasmaexchanges for recovery, which proofed to be significant at 2% level in a one sided t-test. Tingling (64.7%) and shivering (51%) were the most often mentioned side effects and simultaneously described as the strongest. Shivering was significantly correlated to tachycardia (p<0.01). Headaches were significantly correlated to hot flushes, tingling and collapse (p< 0.05). Side effects and allergic reactions occurred in the therapy with FFP as well as with s/d plasma. Another side effect was the complication that came along with infection of the venous access. Most patients had a central venous catheter (72%) and described infections and pruritus (60%), 50% of them mentioned this complication more than once. We found in usual FFP slightly higher ADAMTS13 activity levels (696.97 ng/ml) than in s/d virus inactivated plasma (643.86 ng/ml). The ADAMTS13 activity varied between the different assays (normal range: 666 ± 135ng/ml). Conclusion: Our investigation demonstrated that plasmaexchange therapy is still associated with a wide range of side effects. Side effects of plasmaexchange that were most frequently described by patients were tingling and shivering. Headaches also occurred in various cases. Patients suffered generally from more than one side effect at the same time during the treatment. Allergic reactions to the plasma therapy were mentioned by 65% of the patients. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4674-4674
Author(s):  
Xia Bai ◽  
Jian Su ◽  
Minghua Jiang ◽  
Zhaoyue Wang ◽  
Changgeng Ruan

Abstract Abstract 4674 Congenital thrombotic thrombocytopenic purura (TTP) is caused by gene mutations of von Willebrand factor-cleaving protease (a disintegrin and metalloprotease with thrombospondin type I domains 13, ADAMTS13). In this study, one novel mutation in the ADAMTS13 gene was found in a woman whose presents are first cousins. Thrombocytopenia occurred during the second trimesters in her first pregnancy, and she died of recurrent attacks after diagnosis of TTP. The ADAMTS13 activity measured using the recombinant FRET-VWF73 during her acute episode was less than 5%. ADAMTS13 inhibitor was negative measured by 9:1 mixture of patient and pooled normal plasma followed by ADAMTS13 activity assay using the VWF multimer electrophoresis. The 29 exons and exon-intron boundary sites of ADAMTS13 gene was analyzed using the human genomic DNA extracted from peripheral leukocytes of the patient. The results demonstrated she was homozygous for R498C. This novel mutant was constructed using the expression plasmid pSectag containing ADAMTS13 cDNA, and the vector was introduced by linpofectamine 2000 to Hela cells. Western Blot revealed that rADAMTS13-wide type (WT) was synthesized as a single band with molecular mass close to 190 Kda in the conditioned media, however, no detectable ADAMTS13 of this mutant existed. The lysates of cells expressing the mutant showed the same protein amounts compared to the rADAMTS13-WT. The immunofluorescence study demonstrated that mutant had the same localization pattern at Endoplasmic Reticulum(ER)and Golgi-compartments compared to the rADAMTS13-WT. The results imply that this mutant may be retained in the cellular ER and Golgi-comparments, but rapidly degraded or insufficiently secreted. Disclosures: No relevant conflicts of interest to declare.


2012 ◽  
Vol 59 (7) ◽  
pp. 1296-1298 ◽  
Author(s):  
Timothy D. Prestidge ◽  
Erica Rurali ◽  
Louis Wadsworth ◽  
John K. Wu ◽  
Jane C. Moore ◽  
...  

2014 ◽  
Vol 112 (08) ◽  
pp. 297-303 ◽  
Author(s):  
Ilaria Mancini ◽  
Carla Valsecchi ◽  
Luca Lotta ◽  
Louis Deforche ◽  
Silvia Pontiggia ◽  
...  

SummaryCollagen-binding activity (CBA) and FRETS-VWF73 assays are widely adopted methods for the measurement of the plasmatic activity of ADAMTS13, the von Willebrand factor (VWF) cleaving-protease. Accurately assessing the severe deficiency of ADAMTS13 is important in the management of thrombotic thrombocytopenic purpura (TTP). However, non-concordant results between the two assays have been reported in a small but relevant percentage of TTP cases. We investigated whether CBA or FRETS-VWF73 assay reflects ADAMTS13 proteolytic activity in acquired TTP patients with non-concordant measurements. Twenty plasma samples with non-concordant ADAMTS13 activity results, <10% using FRETS-VWF73 and ≥20% using CBA, and 11 samples with concordant results, <10% using either FRETS-VWF73 and CBA assays, were analysed. FRETS-VWF73 was performed in the presence of 1.5 M urea. ADAMTS13 activities were also measured under flow conditions and the VWF multimer pattern was defined in order to verify the presence of ultra-large VWF due to ADAMTS13 deficiency. In FRETS-VWF73 assay with 1.5 M urea, ADAMTS13 activity significantly increased in roughly 50% of the samples with non-concordant results, whereas it remained undetectable in all samples with concordant measurements. Under flow conditions, all tested samples showed reduced ADAMTS13 activity. Finally, samples with non-concordant results showed a ratio of high molecular weight VWF multimers higher than normal. Our results support the use of FRETS-VWF73 over CBA assay for the assessment of ADAMTS13 severe deficiency and indicate urea as one cause of the observed differences.


Blood ◽  
2002 ◽  
Vol 100 (3) ◽  
pp. 778-785 ◽  
Author(s):  
Giuseppe Remuzzi ◽  
Miriam Galbusera ◽  
Marina Noris ◽  
Maria Teresa Canciani ◽  
Erica Daina ◽  
...  

Abstract Whether measurement of ADAMTS13 activity may enable physicians to distinguish thrombotic thrombocytopenic purpura (TTP) from hemolytic uremic syndrome (HUS) is still a controversial issue. Our aim was to clarify whether patients with normal or deficient ADAMTS13 activity could be distinguished in terms of disease manifestations and multimeric patterns of plasma von Willebrand factor (VWF). ADAMTS13 activity, VWF antigen, and multimeric pattern were evaluated in patients with recurrent and familial TTP (n = 20) and HUS (n = 29). Results of the collagen-binding assay of ADAMTS13 activity were confirmed in selected samples by testing the capacity of plasma to cleave recombinant VWF A1-A2-A3. Most patients with TTP had complete or partial deficiency of ADAMTS13 activity during the acute phase, and in some the defect persisted at remission. However, complete ADAMTS13 deficiency was also found in 5 of 9 patients with HUS during the acute phase and in 5 patients during remission. HUS patients with ADAMTS13 deficiency could not be distinguished clinically from those with normal ADAMTS13. In a subgroup of patients with TTP or HUS, the ADAMTS13 defect was inherited, as documented by half-normal levels of ADAMTS13 in their asymptomatic parents, consistent with the heterozygous carrier state. In patients with TTP and HUS there was indirect evidence of increased VWF fragmentation, and this occurred also in patients with ADAMTS13 deficiency. In conclusion, deficient ADAMTS13 activity does not distinguish TTP from HUS, at least in the recurrent and familial forms, and it is not the only determinant of VWF abnormalities in these conditions.


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