Thrombotic thrombocytopenic purpura in systemic lupus erythematosus: A frequent and severe consequence of active disease

Cumulative Review of Thrombotic Microangiopathy, Thrombotic Thrombocytopenic Purpura, and Hemolytic Uremic Syndrome Reports with Subcutaneous Interferon β-1a

INTRODUCTION

Rare cases of thrombotic microangiopathy (TMA), manifested as thrombotic thrombocytopenic purpura (TTP) or hemolytic uremic syndrome (HUS), have been reported with interferon β products. We performed a cumulative review of TMA cases recorded in a Global Safety Database for patients with multiple sclerosis who received subcutaneous interferon β-1a treatment.

METHODS

Search criteria were: all reported cases, serious and non-serious, from all sources (including non-health care professionals and clinical trial reports), regardless of event ranking and causality assessment by reporter or company. Data lock was May 3, 2014, with additional analysis of cases reported between August 1, 2014-November 30, 2014.

RESULTS

Ninety-one patient cases (76.9% female) with 105 events were retrieved. Time to onset varied from 2 months to 14 years, and in 31.9% of patients the event occurred within 2 years of treatment initiation. Seven patients had a fatal outcome (five were secondary to other causes and two reported insufficient information). Forty-four patients recovered, 32 patients had not recovered at the time of the report, and in eight cases outcome was either not reported or unknown. Treatment was discontinued in 84.6% (77/91) of patients. In 67% (61/91) of patients, the reporter suspected a causal association between treatment and TMA/TTP-HUS. Risk factors and/or confounding factors were present in 45.1% (41/91) of patients. Early prodromal syndrome or specific patterns were not detected, although 54.9% (50/91) of cases contained insufficient information. Overall reporting rate of TMA/TTP-HUS was estimated as 7.2 per 100,000 patient-years. Reporting rates for human serum album (HSA)-containing and HSA-free formulations were 5.72 and 7.68 per 100,000 patient-years, respectively.

CONCLUSION

No new signal relating specifically to increased frequency of TMA/TTP-HUS with HSA-free subcutaneous interferon β-1a was detected and no additional risk mitigation measures are required regarding the different formulations. The benefit-risk balance of subcutaneous interferon β-1a remains positive, and routine pharmacovigilance monitoring is appropriate.

FUNDING

Ares Trading SA, Aubonne, Switzerland, a subsidiary of Merck Serono SA.

Increased expression of ADAMTS13 mRNA correlates with ischemic cerebrovascular disease in systemic lupus erythematosus patients

Objective:

We investigated ADAMTS13 (a disintegrin-like and metalloprotease with thrombospondin type 1 motif, member 13) messenger RNA levels as a biomarker of disease features in systemic lupus erythematosus.

Methods:

We measured and compared messenger RNA (mRNA) levels of ADAMTS13 in peripheral blood cells in patients with systemic lupus erythematosus and healthy control subjects by whole-genome microarray. We retrospectively analyzed the correlations of ADAMTS13 mRNA expression with clinical features, laboratory parameters, therapeutic features, and disease activity (according to the Systemic Lupus Erythematosus Disease Activity Index). We also examined the association of three single nucleotide polymorphisms (rs4962145, rs2285467, and rs685523) of the ADAMTS13 gene with patient characteristics.

Results:

In 309 patients, the median ADAMTS13 mRNA expression levels were significantly higher in blood cells of systemic lupus erythematosus patients than in 23 healthy controls (p = .03). Notably, ADAMTS13 mRNA expression levels were significantly higher in systemic lupus erythematosus patients with a history of stroke (p = .02) or transient ischemic attack (p = .02). Among the three single nucleotide polymorphisms analyzed, rs2285467 was significantly associated with stroke (p = .03) and anticardiolipin antibodies (p = .04).

Conclusions:

Increased expression of ADAMTS13 mRNA in blood cells is associated with the presence of ischemic cerebrovascular disease in systemic lupus erythematosus patients and suggests a potential role for ADAMTS13 in the pathogenesis of ischemic cerebrovascular disease in these patients.

Rapidly progressive lupus nephritis and concomitant thrombotic microangiopathy

Although uncommon, thrombotic microangiopathy (TMA) is one of the most serious complications in patients with systemic lupus erythematosus. A 30-year-old black woman admitted to our hospital because of fever, fatigue, 'dark' urine and rapidly progressive renal failure was found to have systemic lupus erythematous and atypical hemolytic uremic syndrome. Kidney biopsy showed WHO class IV lupus nephritis with crescents and TMA. Hemodialysis was initiated for worsening renal failure. The patient was treated with corticosteroids, monthly pulse intravenous Cyclophosphamide, plasmapheresis and Rituximab on a weekly basis for 4 weeks. The patient's blood pressure was aggressively controlled using antihypertensive agents. Despite this extensive therapy, she remained dialysis dependent although hematological parameters returned to normal values.

Effect of blood group on idiopathic thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a condition caused by deficiency of ADAMTS13 resulting in accumulation of ultra large Von Willebrand factor multimers (ULVWF), leading to micro thrombi in multiple organs. The varying susceptibilities of blood group antigens to ADAMTS13 have been demonstrated. A and B antigens are protective of VWF; and VWF purified from blood group O individuals has been shown to be cleaved faster by ADAMTS13 compared to VWF from blood group AB individuals. We proposed that there may be a difference in the incidence of blood groups in TTP patients compared with the general population. We felt this to be important for a life-threatening disease with poorly understood epidemiology. We report a retrospective analysis of 74 patients presenting from 1993 to 2008 with idiopathic TTP. We studied the incidence across various blood groups and also estimated the recurrence and mortality in each group. The incidence of various blood groups were as follows: O 36%, A 36%, B 25%, and AB 2%, compared with expected frequencies in the Detroit area: O 44%, A 33% B 20%, and AB 3%. There was a trend of lower than expected frequency of blood group O. There were 24 recurrences and 14 deaths, uniform across blood groups. We hypothesized that there may be an association between blood groups and the risk of TTP; however the differences in our study were not statistically significant. Recurrence and disease specific mortality did not appear to be impacted by blood group.

Lupus nephritis combined with renal injury due to thrombotic thrombocytopaenic purpura-haemolytic uraemic syndrome

BACKGROUND

Thrombotic thrombocytopaenic purpura-haemolytic uraemic syndrome (TTP-HUS) in SLE was reported mainly in isolated case reports. The aim of this study is to investigate the clinical and pathological features, outcome and possible pathogenesis of TTP-HUS in patients with lupus nephritis.

METHODS

Clinical and renal histopathological data of patients with lupus nephritis were reviewed for clinical and pathological evidence of both TTP-HUS and renal thrombotic microangiopathy (TMA). Serum ADAMTS-13 activity and ADAMTS-13 autoantibodies were further studied.

RESULTS

Seven patients with evidence of both TTP-HUS and renal TMA were identified in 353 patients with lupus nephritis. In comparison with 55 patients with lupus nephritis without TTP-HUS, those with TTP-HUS had a higher prevalence of acute renal failure and worse renal outcome. The serum ADAMTS-13 activity was significantly lower in patients with both lupus nephritis and TTP-HUS than in patients with lupus nephritis only and in normal control (40% versus 69%, P = 0.012; 40% versus 81%, P < 0.001, respectively). The prevalence of ADAMTS-13 autoantibodies was significantly higher in patients with both lupus nephritis and TTP-HUS than in patients with lupus nephritis only and in normal control (6/7, 86% versus 10/55, 18%, P < 0.001; 6/7, 86% versus 0, P < 0.001, respectively). After clinical remission, the serum ADAMTS-13 activity of the seven patients with TTP-HUS increased significantly (40% versus 63%, P < 0.001) and five out of the six patients with positive ADAMTS-13 autoantibodies turned negative.

CONCLUSIONS

ADAMTS-13 autoantibodies might play an important role in the pathogenesis of TTP-HUS associated with lupus nephritis. The long-term outcome seems to be worse in patients with both TTP-HUS and lupus nephritis than in patients with lupus nephritis alone.