Barbara Ferrari

Thromboembolic Complications in Malignant Haematological Disorders

It is well known that solid cancers are associated with thromboembolic complications, but recent studies have shown that the incidence of thrombosis may be as high (or even higher) in patients with malignant haematological disorders. However, this may be obscured by the significant morbidity and mortality due to other complications of haematological malignancies, such as bleeding and infections. The vast majority of patients with haematological neoplasias also have clinically silent haemostatic abnormalities, but some may show clinical manifestations, including venous thromboembolism, pulmonary embolism, disseminated intravascular coagulation and life-threatening thrombohaemorrhagic syndrome in acute leukaemias. The pathogenesis of thromboembolic disease in haematological malignancies is complex and multifactorial: tumour cell-derived procoagulant, fibrinolytic or proteolytic factors and inflammatory cytokines affect clotting activation, and chemotherapy and anti-angiogenic drugs increase thrombotic risk in patients with lymphoma, acute leukaemia and multiple myeloma. Infectious complications are another important factor: endotoxins from gram-negative bacteria induce the release of tissue factor (TF), Tumor Necrosis Factor (TNF) and interleukin-1b (IL-1b), and gram-positive organisms can release bacterial mucopolysaccharides that directly activate factor XII. Leukaemic patients may be affected by other prothrombotic factors, including hyperleukocytosis, increased TF expression and activation, and the prothrombotic properties of therapeutic agents such as all-trans retinoic acid and L-asparaginase, which can induce thrombosis involving multiple organs. The very high risk of haemorrhaging in these patients warrants prospective randomised trials evaluating optimal anti-thrombotic prophylaxis and treatment.

Urinary Sediment Findings in Acute Interstitial Nephritis

RESEARCH LETTERS Urinary Sediment Findings in Acute Interstitial Nephritis To the Editor: Acute interstitial nephritis (AIN) is a condition characterized by acute kidney injury associated with acute cellular infiltrate of the renal interstitium due to various causes. Published data for urinary sediment findings in AIN are few. In this case series, we describe detailed findings observed in 21 patients with biopsy-proven AIN due to different causes. We reviewed all reports of biopsies performed on native kidneys at our institution during a 14-year period (January 1, 1997, to February 1, 2011) and identified AIN cases. All patients with AIN were considered for inclusion. All microscopic slides arising from these kidney biopsies were reviewed by 2 of us for the presence or absence of interstitial cellular infiltrate, tubulitis, tubular necrosis, tubular basement membrane gaps, interstitial red blood cell (RBC) extravasation, RBCs, and intratubular RBC casts. Of 839 kidney biopsies, 23 (2.7%) were found to have AIN in the absence of significant glomerular lesions. We included 21 patients (Table 1), having excluded one because of bacteria (2 ) in the urinary sediment and another for focal glomerular immunoglobulin A and C3 by immunofluorescence (which was negative at the glomerular level in all other cases).

Pregnancy complications in acquired thrombotic thrombocytopenic purpura: a case-control study

BackgroundPregnant women with a history of acquired thrombotic thrombocytopenic purpura (TTP) are considered at risk for disease recurrence and might be at risk for miscarriage, similar to other autoimmune disorders. However, the exact entity of these risks and their causes are unknown. The aim of this study was to evaluate risk factors associated with adverse pregnancy outcome, in terms of both gravidic TTP and miscarriage, in women affected by previous acquired TTP.MethodsWe conducted a nested case–control study in women with a history of acquired TTP enrolled in the Milan TTP registry from 1994 to October 2012, with strict inclusion criteria to reduce referral and selection bias.ResultsFifteen out of 254 women with acquired TTP were included, namely four cases with gravidic TTP, five with miscarriage, and six controls with uncomplicated pregnancy. In the cases, ADAMTS13 activity levels in the first trimester were moderately-to-severely reduced (median levels <3% in gravidic TTP and median levels 20% [range 14-40%] in the women with miscarriage) and anti-ADAMTS13 antibodies were invariably present, while in the control group ADAMTS13 activity levels were normal (median 90%, range 40-129%), with absence of detectable anti-ADAMTS13 antibodies. Reduced levels of ADAMTS13 activity (<25%) in the first trimester were associated with an over 2.9-fold increased risk for gravidic TTP and with an over 1.2-fold increased risk for miscarriage (lower boundary of the confidence interval of the odds ratio). In addition, the presence of anti-ADAMTS13 antibodies during pregnancy was associated with an over 6.6-fold increased risk for gravidic TTP and with an over 4.1-fold increased risk for miscarriage.ConclusionsADAMTS13 activity evaluation and detection of anti-ADAMTS13 antibody could help to predict the risk of complications in pregnant women with a history of acquired TTP.

Two novel heterozygote missense mutations of the ADAMTS13 gene in a child with recurrent thrombotic thrombocytopenic purpura.

BACKGROUND Thrombotic thrombocytopenic purpura is a rare, life-threatening disease characterised by microangiopathic haemolytic anaemia, thrombocytopenia and symptoms related to organ ischaemia, mainly involving the brain and the kidney. It is associated with a deficiency of ADAMTS13, a plasma metalloprotease that cleaves von Willebrand factor. The congenital form (Upshaw-Schulman syndrome) is rare and is associated with mutations of the ADAMTS13 gene on chromosome 9q34. The clinical symptoms of congenital thrombotic thrombocytopenic purpura are variable, with some patients developing their first episode during the neonatal period or childhood and others becoming symptomatic in adulthood. MATERIALS AND METHODS We describe a case of thrombotic thrombocytopenic purpura, who presented to our attention with a relapsing form of the disease: the first episode occurred at the age of 13 months. Phenotype and genotype tests were performed in the patient and his family. RESULTS The undetectable level of ADAMTS13 in the patient was caused by two novel heterozygote missense mutations on the ADAMTS13 gene: one mutation is c.788C > T (p.Ser263Phe) on exon 7 and the second is c.3251G > A (p.Cys1084Tyr) on exon 25 of the ADAMTS13 gene. All the relatives who have been investigated were found to carry one of these missense mutations in a heterozygous state. DISCUSSION Although Upshaw-Schulman syndrome is a rare disease, it should be considered in all children with thrombocytopenia and jaundice in the neonatal period. In fact, once a child is confirmed to carry mutations of the ADAMTS13 gene causing early thrombotic thrombocytopenic purpura, prophylactic treatment should be started to avoid recurrence of symptoms. Genotype tests of relatives would also be important for those women in the family who could be carriers of ADAMTS13 mutations, particularly during pregnancy.

ADAMTS13-specific circulating immune complexes as potential predictors of relapse in patients with acquired thrombotic thrombocytopenic purpura.

BACKGROUND Acquired thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy due to the development of autoantibodies against the VWF-cleaving protease ADAMTS13. ADAMTS13-specific circulating immune complexes (CICs) have been described in patients with acquired TTP, but their clinical relevance remained to be established. The aim of this study was to assess the association between ADAMTS13-specific CICs and ADAMTS13-related measurements, clinical and laboratory markers of disease severity, and occurrence of TTP relapse, in autoimmune TTP patients. MATERIAL AND METHODS We measured ADAMTS13-specific CICs in 51 patients with severe ADAMTS13 deficiency and anti-ADAMTS13 autoantibodies, at the first episode of acquired TTP. The associations between ADAMTS13-specific CICs and the variables of interest were assessed by linear, logistic and Cox proportional hazard regression models, where appropriate. RESULTS The prevalence of ADAMTS13-specific CICs in patients experiencing the first TTP episode was 39% (95% confidence intervals [CI]: 26-52%). ADAMTS13-specific CICs were not associated neither with laboratory markers of disease severity, nor with patterns of clinical presentation. Conversely, among 45 survivors, a positive association was found between the presence of ADAMTS13-specific CICs and the risk of recurrence within 2years after the first TTP episode (adjusted hazard ratio, 3.4 [95% CI: 0.9 to 13.5]). CONCLUSIONS ADAMTS13-specific CICs seem to be able to predict the recurrence of acute TTP episodes in the first 2years after disease onset. Therefore, their measurement might be used as a tool to stratify the risk of disease relapse, with potential influence on surveillance and therapeutic choices during remission phase.

Immunochip analysis identifies novel susceptibility loci in the human leukocyte antigen region for acquired thrombotic thrombocytopenic purpura.

Essentials Genetic predisposition to acquired thrombotic thrombocytopenic purpura (aTTP) is mainly unknown. Genetic risk factors for aTTP were studied by Immunochip analysis and replication study. Human leukocyte antigen (HLA) variant rs6903608 conferred a 2.5‐fold higher risk of developing aTTP. rs6903608 and HLA‐DQB1*05:03 may explain most of the HLA association signal in aTTP.

Thrombotic microangiopathy without renal involvement: two novel mutations in complement-regulator genes.

Essentials The differential diagnosis among thrombotic microangiopathies (TMAs) is challenging. We studied a case of TMA with neurologic symptoms, no renal impairment and normal ADAMTS‐13 levels. Two novel mutations in complement factor I and thrombomodulin genes were identified. Complement‐regulator genes can be involved in TMAs with normal ADAMTS‐13 regardless of renal damage.

Congenital and acquired ADAMTS13 deficiency: Two mechanisms, one patient

Thrombotic thrombocytopenic purpura (TTP) is a life‐threatening microangiopathy with a heterogeneous and largely unpredictable course. It is caused by ADAMTS13 deficiency, that can be either congenital or due to anti‐ADAMTS13 autoantibodies development. ADAMTS13 deficiency is necessary but not always sufficient to cause acute clinical manifestations and trigger factors may be needed. We report the case of a woman diagnosed with congenital TTP in her adulthood, presenting with anti‐ADAMTS13 autoantibodies in acute phase during ticlopidine consumption. Noteworthy, the two ADAMTS13 mutations identified in this patient are novel: one is a splice‐site mutation located in intron 11 (c.1308+2_5delTAGG) and the other is a point missense mutation in exon 29 (c.4184T>C leading to p.Leu1395Pro substitution). Since congenital TTP is an extremely rare disease and drug‐induced TTP is an uncommon side effect of treatment with ticlopidine, the simultaneous occurrence of both mechanisms of disease in one patient is exceptional. This case represents TTP as a multifactorial disease, with ADAMTS13 genetic abnormality and environmental exposures acting together in determining individual clinical phenotype. J. Clin. Apheresis 30:252–256, 2015.

Acute interstitial nephritis after amoxycillin with hematuria, red blood cell casts and hematuria-induced acute tubular injury.

A 62-year-old Caucasian man is described who developed acute kidney injury (AKI) and gross hematuria after a course with amoxycillin. At admission, urinalysis showed mild proteinuria, marked microscopic hematuria and cylindruria, which also included red blood cell casts. At renal biopsy an acute interstitial nephritis (AIN) was found, which was associated with many intratubular red blood cells and red blood cell casts, consequent acute tubular injury and red blood cell phagocytosis by tubular cells. After a course with corticosteroids, renal function partly recovered. This case demonstrates that red blood cell cylindruria, red blood cell intratubular casts and red blood cell-induced tubular injury can also be observed in patients with acute interstitial nephritis and not only in patients with glomerulonephritis as described so far.