Thrombotic thrombocytopenic purpura associated with mixed connective tissue disease: a case report

An Autopsy Case of Mixed Connective Tissue Disease Complicated by Thrombotic Thrombocytopenic Purpura

We herein report a patient with mixed connective tissue disease (MCTD) who had been stable for years but suddenly developed thrombotic thrombocytopenic purpura (TTP). The patient showed a clinical pentad of signs of TTP, low activity of ADAMTS13, and positivity of anti-ADAMTS13 antibodies. She did not respond to plasma exchange or steroid therapy and died five days after admission. An autopsy revealed microthrombi in the brain, heart, kidney, adrenal glands, esophageal submucosa, and bone marrow as well as diffuse alveolar hemorrhaging. Physicians should bear in mind that TTP can occur in MCTD patients regardless of disease activity.

The color of skin: purple diseases of the skin, nails, and mucosa

The color purple can be seen in several types of eruptions including inflammatory dermatoses like lichen planus, infectious dermatoses like ecthyma gangrenosum, neoplasms like Kaposi sarcoma, and vasculitis and vasculopathy. The current review focuses on the clinical appearance, pathophysiology, and treatment of several vasculitides and vasculopathies including capillaritis, cutaneous small-vessel vasculitis, immunoglobulin A (IgA) vasculitis, cryoglobulinemia, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, microscopic polyangiitis, polyarteritis nodosum, warfarin-induced skin necrosis, heparin-induced thrombocytopenia, purpura fulminans, antiphospholipid antibody syndrome, calciphylaxis, levamisole-induced vasculopathy, and thrombotic thrombocytopenic purpura. Dermatologists play a central role in treating patients with cutaneous vasculitis and vasculopathy and may have the opportunity to facilitate identification of systemic disease by diagnosing cutaneous vasculitis and vasculopathy.

From anemia to polycythemia in 4 weeks

Primary polycythemia (PCV) may coexist in otherwise asymptomatic patients particularly in the presence of unsuspecting conditions such as Thrombotic thrombocytopenic purpura (TTP). In presumed “idiopathic TTP,” autoimmune conditions such as rheumatoid arthritis (RA) should be investigated as a possible etiology for TTP. Standardization of targeted therapy with immunomodulatory agents may be recommended for this subset of patients.

Derivation and external validation of the PLASMIC score for rapid assessment of adults with thrombotic microangiopathies: a cohort study

BACKGROUND

Among the syndromes characterised by thrombotic microangiopathy, thrombotic thrombocytopenic purpura is distinguished by a severe deficiency in the ADAMTS13 enzyme. Patients with this disorder need urgent treatment with plasma exchange. Because ADAMTS13 activity testing typically requires prolonged turnaround times and might be unavailable in resource-poor settings, a method to rapidly assess the likelihood of severe ADAMTS13 deficiency is needed.

METHODS

All consecutive adult patients presenting to three large academic medical centres in Boston, MA, USA, with thrombotic microangiopathy and a possible diagnosis of thrombotic thrombocytopenic purpura between Jan 8, 2004, and Dec 6, 2015, were included in an ongoing multi-institutional registry (the Harvard TMA Research Collaborative). Univariate analysis was used to identify covariates for a logistic regression model predictive of severe ADAMTS13 deficiency (≤10% activity). A clinical point score was generated, and its diagnostic performance was assessed using internal and external validation cohorts and compared to clinical assessment alone.

FINDINGS

214 patients with thrombotic microangiopathy were included in the derivation cohort. A seven-component clinical prediction tool, termed the PLASMIC score, was developed and found to reliably assess the pretest probability of severe ADAMTS13 deficiency (C statistic 0·96, 95% CI 0·92-0·98). Our diagnostic model was reproducibly accurate in both the internal (0·95, 0·91-0·98) and external (0·91, 0·85-0·95) validation cohorts. The scoring system also more consistently diagnosed thrombotic microangiopathy due to severe ADAMTS13 deficiency than did standard clinical assessment, as measured by C statistic (0·96, 95% CI 0·92-0·98 for PLASMIC vs 0·83, 0·77-0·88 for clinical assessment; p<0·0001) and mean Brier score (0·065 for PLASMIC vs 0·111 for clinical assessment; mean paired difference 0·05, 95% CI 0·01-0·08; p<0·0001). When utilised in addition to clinical assessment, the PLASMIC score contributed significant discriminatory power (integrated discrimination improvement 0·24, 95% CI 0·11-0·37).

INTERPRETATION

We have developed and validated a clinical prediction tool-the PLASMIC score-to stratify patients with thrombotic microangiopathy according to their risk of having severe ADAMTS13 deficiency. We have shown that this scoring system is superior to standard clinical assessment in addressing the diagnostic challenge presented by thrombotic microangiopathy. Its use, together with clinical judgment, may facilitate treatment decisions in patients for whom timely results of ADAMTS13 activity testing are unavailable.

FUNDING

The Luick Family Fund of Massachusetts General Hospital.