Israel Medical Association Journal

IgA vasculitis, formerly known as Henoch–Schönlein purpura (HSP), is the most common systemic vasculitis in children. It is defined as palpable purpura in the absence of coagulopathy or thrombocytopenia and one or more of the following criteria: abdominal pain, arthritis or arthralgia, biopsy of affected tissue demonstrating predominant IgA deposition, and renal involvement with proteinuria and hematuria or red cell casts [1].

At the end of 2019, the world faced a new virus–coronavirus disease 2019 (COVID-19)–which quickly became a pandemic. It has become clear that the COVID-19 virus can affect various body systems. Over time, we are finding more and more diverse manifestations of the course of the disease itself, its consequences, and complications. There have been several studies and reviews describing circulating antibodies in patients infected with COVID-19 (e.g., antinuclear antibodies [ANA], anti-cardiolipin, anti-B2 glycoprotein, perinuclear anti-neutrophil cytoplasmic antibodies [p-ANCA], cytoplasmic ANCA [c-ANCA]). The development of autoimmune disorders has been reported (e.g., Graves' disease, systemic lupus erythematosus (SLE), immune thrombocytopenia [ITP], diabetes mellitus [DM] type 1, psoriasis). There are descriptions of COVID-19 associated vasculitis include Kawasaki-like symptoms in children and immunoglobulin A (IgA) vasculitis in children and adults [1].

Background: Secondary immune thrombocytopenic purpura (ITP) associated with coronavirus disease 2019 (COVID-19) is a rare but serious complication of the pandemic. Diagnostic criteria include clinical and laboratory findings. Early treatment is often effective, but rare severe bleeding and death can occur. An autoimmune mechanism is likely.

Objectives: To determine a role for molecular mimicry in producing disease.

Methods: Hexapeptide and heptapeptide matches between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and platelet N-glycosylated proteins and other human proteins were assessed.

Results: Shared viral and platelet glycoprotein peptides were found. Copy frequency of these peptides in the human proteome was low for many of the candidate molecular mimics.

Conclusions: The data support a contribution of molecular mimicry in COVID-19 ITP autoimmunity and offer avenues for in vitro diagnostic assay development. The continuation of the pandemic necessitates additional understanding of COVID-19 ITP as well as studies on diagnosis and mitigation.

Acquired thrombotic thrombocytopenic purpura (TTP) is an uncommon disease in adults, characterized by fever, neurological manifestations, microangiopathic hemolytic anemia, thrombocytopenia, renal dysfunction, and the presence of antibodies against the enzyme ADAMTS13. Treatment with plasmapheresis has increased the survival from 10% to more than 90%. Still, there is a subset of patients with resistant TTP who fail to respond to plasmapheresis or remain dependent on this procedure. There is mounting evidence that rituximab may play an important role in remission induction of resistant/relapsing TTP; however, the extent of the remission is unknown. We present here four patients with chronic-relapsing TTP who responded favorably to rituximab. All four patients achieved prolonged remission of 23 to 82 months after the treatment.  One patient relapsed 6 years after the initial treatment with rituximab and re-entered remission following retreatment.

Intussuception is the most common cause of intestinal obstruction in early childhood. The cause of most intussusceptions is unknown but it can complicate the course of Henoch-Schonlein purpura (HSP) as a result of the vasculitic process. Familial Mediterranean fever (FMF), a most common disease in Israel is also associated with HSP. In a few patients, particularly in children, HSP has been reported to precede the diagnosis of FMF. We describe two patients with an unusual clinical course of severe abdominal pain as a result of intusucception. The correlation between intusucception, HSP and FMF are discussed.
 

Objectives: To describe patients with initially misdiagnosed PTP[1] and to emphasize the diagnostic pitfalls of this disorder.

Patients and Results: During a period of 11 years we have diagnosed six patients with PTP, four women and two men. The incidence of PTP was approximately 1:24,000 blood components transfused. We present the detailed clinical course of three of the six patients in whom the diagnosis was particularly challenging. The patients were initially misdiagnosed as having heparin-induced thrombocytopenia, systemic lupus erythematosus complicated by autoimmune thrombocytopenia, and disseminated intravascular coagulation. A history of recent blood transfusion raised the suspicion of PTP and the diagnosis was confirmed by appropriate laboratory workup.

Conclusions: PTP seems to be more frequent than previously described. The diagnosis should be considered in the evaluation of life threatening thrombocytopenia in both men and women with a recent history of blood transfusion.