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Thrombotic thrombocytopenia purpura is characterised by microangiopathic haemolytic anaemia and red cell fragmentation on the peripheral smear, neurological involvement and thrombocytopenia. Diagnosis in the context of sickle cell disease can be challenging due to the inherent haemolytic state and the multitude of other associated complications of the latter. Specifically, fat embolism syndrome characterised by respiratory failure, neurological impairment and thrombocytopenia can be misdiagnosed this way. Confirmation of a diagnosis of thrombotic thrombocytopenic purpura requires demonstration of very low levels (

Thrombotic thrombocytopenic purpura (TTP) is a rare thrombomicroangiopathy caused by deficiency of ADAMTS13. Acute neurological involvement is well described, but its long-term impact requires evaluation. One-hundred thirty-one patients, following an acute TTP event, with severe headache or neurological symptoms had a cerebral MRI. Fifty-six percent had abnormal imaging, more commonly in patients with neurological symptoms than headaches only (80% vs. 18%, P < 0·0001). In remission, 27% (n = 35) reported persistent cognitive symptoms: specifically, impaired memory (66%), difficulty concentrating (26%), and word-finding difficulties not secondary to an acute stroke (26%). Sixty-five percent also reported depression and 55% reported anxiety, regardless of presenting neurology. The frontal lobe was disproportionally affected in patients with marked intellectual impairment, seen in 67% of patients compared to 19% of patients without intellectual impairment (P = 0·002). The primary MRI finding in these patients was hyperintense white matter lesions. An abnormal MRI was associated with a lower median verbal IQ (85 vs. 99, P = 0·02) and performance IQ (83 vs. 100, P = 0·02). In conclusion, neurological symptoms are frequently associated with an abnormal cerebral MRI scan, and white matter frontal lobe lesions are particularly significant, leading to marked intellectual impairment. Anxiety and depression were evident in over half of patients, regardless of neurological involvement at presentation.

Rituximab, an anti-CD20 monoclonal antibody, can be used to treat immune thrombotic thrombocytopenic purpura (iTTP) during acute presentation or disease relapse. Undesirable side-effects include severe hypersensitivity reactions, particularly anaphylaxis and rituximab-induced serum sickness, with a minority not maintaining a response to treatment. Alternative humanised anti-CD20 treatments, obinutuzumab and ofatumumab, have been used. A review of the UK TTP Registry showed 15 patients received these drugs over 26 treatment episodes (eight obinutuzumab and 18 ofatumumab). Indications for alternative anti-CD20 treatment were severe infusion-related reactions, acute rituximab-induced serum sickness and a short duration of disease remission. All patients achieved disease remission (ADAMTS13 [A disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13] activity ≥30 iu/dl) after a median 15 days and 92% of episodes achieved complete remission (≥60 iu/dl). Seven patients required further treatment for disease relapse with a median relapse-free survival of 17.4 months. All patients continued to respond to re-treatment with the preceding drug when relapse occurred. There were four adverse events in 26 treatment episodes (15%) - two infections and two infusion reactions. These results suggest that obinutuzumab and ofatumumab may be considered as an alternative option to rituximab in the treatment of iTTP with a comparable safety profile, absence of significant hypersensitivity reactions and sustained normalisation of ADAMTS13.

Acquired immune thrombotic thrombocytopenic purpura (iTTP) is a rare disease with a poor prognosis if undiagnosed. It is caused by autoantibody production to the von Willebrand factor (VWF) cleaving protease, A disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13). Caplacizumab, an immunoglobulin directed to the platelet glycoprotein Ibα receptor of VWF, has been reported to induce quicker resolution of iTTP compared to placebo. The laboratory measurement of VWF activity was significantly reduced in clinical trials of caplacizumab. Several VWF assays are available in the UK and this study investigated whether differences in VWF parameters were present in 11 patients diagnosed with iTTP and treated with daily caplacizumab. Chromogenic factor VIII activity, VWF antigen, collagen binding activity, VWF multimers and six VWF activity assays were measured prior to caplacizumab therapy and on several occasions during treatment. VWF antigen and collagen binding activity levels were normal or borderline normal in all patients. Ultra-large molecular weight multimers were present in all patients following treatment. VWF activity assays were normal or reduced during treatment, but this was reagent and patient dependant. In the unusual scenario of a caplacizumab-treated patient requiring measurement of VWF activity, it is important that laboratories understand how their local reagents perform as results cannot be predicted.

Immune thrombotic thrombocytopenic purpura (iTTP) is an acute, multisystem thrombotic microangiopathy mediated by ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) autoantibodies. Immunosuppression with anti-CD20 therapy is the mainstay of treatment. MabThera's patent has now expired and biosimilars have been approved. Eighty-four consecutive patient episodes over 2 years, prior to and following our switch to Truxima are presented. Day 1 (D1), Day 28 (D28) and 3-month platelet counts, ADAMTS13 activity, and CD19 levels, adverse reactions and infective complications were recorded. Platelet counts were not significantly different between acute MabThera and Truxima treatment (D1 P = 0.085, D28 P = 0.77, 3 months P = 0.71) and electively (D1 P = 0.79, D28 P = 0.68, 3 months P = 0.99). ADAMTS13 recovery also was not significantly different acutely (D1 P = 0.99, D28 P = 0.27, 3 months P = 0.26) and electively (D1 P = 0.59, D28 P = 0.61, 3 months P = 0.34). CD19% depletion at D1 and 3 months was not significantly different acutely (D1 P = 0.52, 3 months P = 0.56) and electively (D1 P = 0.22, 3 months P = 0.19). Infusion reactions and infective complications were comparable with both therapies. This is the first series of the Rituximab biosimilar Truxima to be reported in iTTP, demonstrating equivalence to MabThera in terms of ADAMTS13 recovery, CD19 depletion, and platelet count at D28 and 3 months post-administration, with comparable infusion and infective complications. The financial benefit of the biosimilar anti-CD20 is considerable.

Sepsis may be associated with activation of the coagulation system and, in its most severe form, may result in disseminated intravascular coagulation (DIC). Initially, there is thrombosis primarily affecting small and medium sized vessels and contributing to organ dysfunction, but continued activation results in consumption of coagulation factors. This results in prolongation of global coagulation parameters. Often thrombocytopenia is the initial feature in sepsis, which may be followed by prolongation of global coagulation assays, and in severe cases, associated with hypofibrinogenaemia, with overactivation of the fibrinolytic path. The end result is a bleeding phenotype. Scoring systems can be used to help identify patients at risk of DIC and aid in confirming a diagnosis of DIC utilising routine laboratory parameters. Discussion includes medical and blood product support of haemostasis, from thrombotic to bleeding states, in relation to sepsis trigger.

OBJECTIVES Primary immune thrombocytopenia (ITP) is a bleeding disorder characterised by an isolated thrombocytopenia in the absence of an alternative diagnosis. The condition is highly heterogeneous with some patients requiring multiple of therapy before achieving response. In this study, we collected data on a large cohort of primary ITP patients with the objective of identifying variables which may predict treatment requirements. METHODS We collected data on 379 patients, 275 with a confirmed diagnosis of primary ITP included demographics, baseline laboratory results and treatments. These were compared against treatment responses and lines of therapy. RESULTS Patients who presented with a platelet count of 2 lines of therapy (P-value

Introduction: Thrombotic thrombocytopenic purpura (TTP) is an acute life-threatening condition, associated with a low platelet count, hemolytic anemia, fragmentation, and polychromasia on blood fil...

Immune-mediated thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder caused by antibodies against ADAMTS13. From the United Kingdom TTP registry, we undertook a prospective study investigating the impact of the presenting anti-ADAMTS13 IgG antibody and ADAMTS13 antigen on mortality. A total of 312 episodes involving 292 patients over 87 months were included; 68% were female, median age 46 (range, 11-88 years), and median presenting ADAMTS13 of 77%) had a mortality of 16.9% compared with 5.0% for the lowest quartile (antibody 11%) (P = .005). The synergistic effect of anti-ADAMTS13 IgG antibody in the upper quartile and ADAMTS13 antigen in the lowest quartile had the highest mortality of 27.3%. We conclude that both anti-ADAMTS13 IgG antibody and ADAMTS13 antigen levels correlate with outcome in TTP with increased cardiac and neurological involvement and increased mortality.

Mutations in more than 250 genes are implicated in inherited retinal dystrophy; the encoded proteins are involved in a broad spectrum of pathways. The presence of unsolved families after highly parallel sequencing strategies suggests that further genes remain to be identified. Whole-exome and -genome sequencing studies employed here in large cohorts of affected individuals revealed biallelic mutations in ARHGEF18 in three such individuals. ARHGEF18 encodes ARHGEF18, a guanine nucleotide exchange factor that activates RHOA, a small GTPase protein that is a key component of tight junctions and adherens junctions. This biological pathway is known to be important for retinal development and function, as mutation of CRB1, encoding another component, causes retinal dystrophy. The retinal structure in individuals with ARHGEF18 mutations resembled that seen in subjects with CRB1 mutations. Five mutations were found on six alleles in the three individuals: c.808A>G (p.Thr270Ala), c.1617+5G>A (p.Asp540Glyfs ∗ 63), c.1996C>T (p.Arg666 ∗ ), c.2632G>T (p.Glu878 ∗ ), and c.2738_2761del (p.Arg913_Glu920del). Functional tests suggest that each disease genotype might retain some ARHGEF18 activity, such that the phenotype described here is not the consequence of nullizygosity. In particular, the p.Thr270Ala missense variant affects a highly conserved residue in the DBL homology domain, which is required for the interaction and activation of RHOA. Previously, knock-out of Arhgef18 in the medaka fish has been shown to cause larval lethality which is preceded by retinal defects that resemble those seen in zebrafish Crumbs complex knock-outs. The findings described here emphasize the peculiar sensitivity of the retina to perturbations of this pathway, which is highlighted as a target for potential therapeutic strategies.

Inherited retinal disease is a common cause of visual impairment and represents a highly heterogeneous group of conditions. Here, we present findings from a cohort of 722 individuals with inherited retinal disease, who have had whole-genome sequencing (n = 605), whole-exome sequencing (n = 72), or both (n = 45) performed, as part of the NIHR-BioResource Rare Diseases research study. We identified pathogenic variants (single-nucleotide variants, indels, or structural variants) for 404/722 (56%) individuals. Whole-genome sequencing gives unprecedented power to detect three categories of pathogenic variants in particular: structural variants, variants in GC-rich regions, which have significantly improved coverage compared to whole-exome sequencing, and variants in non-coding regulatory regions. In addition to previously reported pathogenic regulatory variants, we have identified a previously unreported pathogenic intronic variant in $\textit{CHM}$ in two males with choroideremia. We have also identified 19 genes not previously known to be associated with inherited retinal disease, which harbor biallelic predicted protein-truncating variants in unsolved cases. Whole-genome sequencing is an increasingly important comprehensive method with which to investigate the genetic causes of inherited retinal disease.

Differentiation between the thrombotic microangiopathies (TMAs) that present in pregnancy may be clinically challenging, but is critical to ensure correct management because of the impact on fetal and maternal outcomes. Thrombotic thrombocytopenic purpura (TTP) and atypical haemolytic uraemic syndrome (aHUS) are medical/obstetric emergencies that require specialist input, both at the time of acute diagnosis and follow-up in subsequent pregnancies. Features of preeclampsia and HELLP syndrome (haemolysis, elevated liver enzymes, low platelets) may precede or be present in evolving TTP or aHUS. Clinicians need to be mindful of how a presumed diagnosis of a specific TMA in pregnancy may evolve and be prepared to frequently reassess signs and symptoms and revise the diagnosis and management plan accordingly.

A 65-year-old man presented with two transient ischaemic attacks, and was then found to have a deep vein thrombosis. He later had recurrent ischaemic strokes. After thorough investigation, the only cause we identified was a previously undiagnosed metastatic pancreatic cancer. We describe the assessment of this presentation and discuss the causes and management of cancer-related stroke.

Introduction L’efficacite du caplacizumab dans le Purpura Thrombotique Thrombocytopenique acquis (PTTa) a ete demontree vs bras controle placebo, les deux bras conjointement a une association echanges plasmatiques et traitement immunosuppresseur, dans les essais de phase 2 TITAN et de phase 3 HERCULES. Sont presentes ici les resultats integres d’efficacite des deux essais. Patients et methodes Tous les patients randomises dans les essais TITAN et HERCULES ont ete inclus dans cette analyse de population. Les patients etaient traites en simple (TITAN) ou double (HERCULES) aveugle puis suivis 30 jours. Les patients de l’essai HERCULES beneficiaient d’un switch vers un bras ouvert caplacizumab en cas de recurrence sous traitement a l’etude. Le critere primaire etait la normalisation plaquettaire, analysee selon les definitions propres aux deux essais. Resultats Un total de 220 patients a ete randomise (108 bras caplacizumab, 112 bras placebo). Les caracteristiques demographiques et cliniques etaient bien equilibrees a l’inclusion hormis les antecedents de PTT plus nombreux dans le bras placebo. Le temps de normalisation plaquettaire est significativement ecourte dans le bras caplacizumab (p Conclusion Cette analyse integree des resultats d’efficacite confirme les resultats des etudes TITAN et HERCULES prises individuellement et montre une normalisation plaquettaire significativement ecourtee dans le bras caplacizumab Vs bras controle. Par ailleurs, Ce traitement permet egalement une reduction significative des deces lies au PTT, des recurrences de PTT ou des evenements thromboemboliques majeurs sous traitement, des deces lies au PTT sous traitement, des recurrences sous traitement et durant la totalite de l’etude, des patients refractaires et du nombre moyen de jours sous echanges plasmatiques.

Thrombotic microangiopathies (TMAs) are frequently difficult to differentiate clinically, and measurement of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) remains vital in thrombotic thrombocytopenic purpura (TTP) diagnosis. We retrospectively reviewed cases referred for ADAMTS13 testing, using UK TTP Registry screening data. Of a total 810 cases, 350 were confirmed as TTP. The 460 non-TTP cases comprised secondary TMAs (24·57%) and haemolytic uraemic syndrome (HUS) (27·17% aHUS, 2·83% Shiga-like toxin-producing E. coli [STEC]-HUS); the remainder were TMAs with no clear association, not TMAs, or had no confirmed diagnosis. ADAMTS13 levels were significantly lower in TTP than STEC-HUS, aHUS and other TMAs. TTP patients had significantly lower platelet count (15 × 10(9) /l; range 0-96) than aHUS (57 × 10(9) /l; range 13-145, P0·0001) or STEC-HUS (35 × 10(9) /l; range 14-106, P0·0001); they also had lower creatinine levels (92 μmol/l; range 43-374) than aHUS (255 μmol/l; range 23-941, P0·0001) and STEC-HUS (324 μmol/l; range 117-639, P0·0001). However, 12/34 (35·3%) aHUS patients had a platelet count30 × 10(9) /l and 26/150 (17·3%) of TTP patients had a platelet count30 × 10(9) /l; 23/150 (15·3%) of TTP patients had a creatinine level150 μmol/l. This study highlights the wide variety of TMA presentations, and confirms the utility of ADAMTS13 testing in TTP diagnosis.

Reduced ADAMTS13 activity is seen in thrombotic thrombocytopenic purpura (TTP), and may lead to accumulation of prothrombotic ultra-large von Willebrand factor (ULVWF) multimers in vivo. ADAMTS13 activity and its relationship with VWF antigen (VWF:Ag) levels and platelet function in 'non-TTP related' TIA or ischaemic stroke has not been comprehensively studied.In this prospective pilot observational analytical case-control study, ADAMTS13 activity and VWF:Ag levels were quantified in platelet poor plasma in 53 patients in the early phase (≤ 4 weeks) and 34 of these patients in the late phase (≥ 3 months) after TIA or ischaemic stroke on aspirin. Data were compared with those from 22 controls not on aspirin. The impact of ADAMTS13 on platelet function in whole blood was quantified by measuring Collagen-ADP (C-ADP) and Collagen-Epinephrine closure times on a platelet function analyser (PFA-100(®)).Median ADAMTS13 activity was significantly reduced in the early phase (71.96% vs. 95.5%, P0.01) but not in the late phase after TIA or stroke compared with controls (86.3% vs. 95.5%, P=0.19). There was a significant inverse relationship between ADAMTS13 activity and VWF:Ag levels in the early phase (r=-0.31; P=0.024), but not in the late phase after TIA or stroke (P=0.74). There was a positive correlation between ADAMTS13 activity and C-ADP closure times in early phase patients only, likely mediated via VWF:Ag levels.ADAMTS13 activity is reduced and VWF:Ag expression is increased within 4 weeks of TIA or ischaemic stroke onset, and can promote enhanced platelet adhesion and aggregation in response to stimulation with collagen and ADP via VWF-mediated pathways. These data improve our understanding of the dynamic haemostatic and thrombotic profiles of ischaemic cerebrovascular disease (CVD) patients, and are important in view of the potential future role that ADAMTS13 may have to play as an anti-thrombotic agent in CVD.

Thrombotic thrombocytopenic purpura diagnosis and therapy has transformed with improved understanding of the disorder and availability of therapies. Plasma exchange remains the cornerstone of treatment. Prompt therapy can improves morbidity and mortality. However, given the plasma volumes used, those offering protection against transfer of microbes are preferable. Reviewed is a brief history of TTP and current plasmas available, their use and safety profiles, concentrating on the current UK recommendations.

Pregnancy can precipitate thrombotic thrombocytopenic purpura (TTP). We present a prospective study of TTP cases from the United Kingdom Thrombotic Thrombocytopenic Purpura (UK TTP) Registry with clinical and laboratory data from the largest cohort of pregnancy-associated TTP and describe management through pregnancy, averting fetal loss and maternal complications. Thirty-five women presented with a first TTP episode during pregnancy: 23/47 with their first congenital TTP (cTTP) episode and 12/47 with acute acquired TTP in pregnancy. TTP presented primarily in the third trimester/postpartum, but fetal loss was highest in the second trimester. Fetal loss occurred in 16/38 pregnancies before cTTP was diagnosed, but in none of the 15 subsequent managed pregnancies. Seventeen of 23 congenital cases had a missense mutation, C3178T, within exon 24 (R1060W). There were 8 novel mutations. In acquired TTP presentations, fetal loss occurred in 5/18 pregnancies and 2 terminations because of disease. We also present data on 12 women with a history of nonpregnancy-associated TTP: 18 subsequent pregnancies have been successfully managed, guided by ADAMTS13 levels. cTTP presents more frequently than acquired TTP during pregnancy and must be differentiated by ADAMTS13 analysis. Careful diagnosis, monitoring, and treatment in congenital and acquired TTP have assisted in excellent pregnancy outcomes.

Introduction Le caplacizumab est un nanocorps divalent inhibant l’adhesion plaquettaire par fixation au domaine A1 du facteur Willebrand. Nous avons evalue son efficacite et sa tolerance dans le traitement du purpura thrombotique thrombocytopenique acquis (PTT). Patients et methodes Des patients traites pour un episode aigu de PTT et ayant beneficie d’un premier echange plasmatique (EP) ont ete randomises avec un ratio 1 :1 entre un bras placebo (PBO) et un bras caplacizumab (CAPLA), en plus d’EP quotidiens et d’une corticotherapie (traitement standard). La periode de traitement couvrait la duree des EP quotidiens et les 30 j suivant leur arret. A la fin de cette periode, une extension de traitement hebdomadaire sur un maximum de 4 semaines pouvait etre proposee en cas d’un deficit severe persistant en ADAMTS13, en plus de l’optimisation du traitement immunosuppresseur. Les patients ont ete suivis 28 jours apres la derniere administration du produit a l’etude. Resultats Cent quarante-cinq patients ont ete randomises, 73 dans le bras PBO et 72 dans le bras CAPLA. Les caracteristiques demographiques ainsi que celles du PTT a l’inclusion etaient comparables hormis un taux plus important d’episodes initiaux de PTT dans le bras CAPLA. La probabilite de normalisation plaquettaire a ete a tout moment accrue de 50 % pour les patients du bras CAPLA comparativement aux patients du bras PBO (ratio de normalisation plaquettaire = 1,55 ; IC95 % [1,10–2,20], p Conclusion Le traitement par caplacizumab reduit le temps de normalisation plaquettaire. Il permet egalement une reduction significative des deces lies au PTT, des recurrences de PTT ou des evenements thromboemboliques majeurs sous traitement. Cette therapeutique a un profil de tolerance favorable avec des saignements mucocutanes rapportes comme etant l’evenement indesirable le plus frequent. Le caplacizumab, grâce a l’inhibition rapide de l’adhesion des plaquettes au facteur Willebrand, represente une nouvelle modalite therapeutique dans la prise en charge du PTT acquis en association au traitement standard (clinicaltrials.gov : NCT02553317 ).

Summary Thrombotic thrombocytopenic purpura (TTP) and atypical haemolytic uraemic syndrome (aHUS) are acute, rare life‐threatening thrombotic microangiopathies that require rapid diagnosis and treatment. They are defined by microangiopathic haemolytic anaemia and thrombocytopenia, with renal involvement primarily in aHUS and neurological and cardiological sequelae in TTP. Prompt treatment for most cases of both conditions is with plasma exchange initially and monoclonal therapy (rituximab in TTP and eculizumab in aHUS) as the mainstay of therapy. Here we discuss the diagnosis and therapy for both disorders.

Thrombotic thrombocytopenic purpura (TTP) and atypical hemolytic uremic syndrome (aHUS) are thrombotic microangiopathies (TMAs) that can present in pregnancy. The presentation can be with typical microangiopathic features and thrombocytopenia, but there is also a significant risk of in-utero fetal loss. TTP presents most commonly in the third trimester and aHUS in the postpartum period. On presumptive diagnosis, plasma exchange should be started and ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) activity measured. An activity of 10% is in keeping with TTP, which may be late-onset congenital TTP or acquired disease: the former will require regular plasma therapy and the latter immunosuppression. In aHUS, eculizumab is the therapy of choice. In future pregnancies, follow-up with a multidisciplinary team including fetomaternal and specialist obstetrics should be undertaken.