Autoimmunity in Thrombotic Thrombocytopenic Purpura

Abstract

In the last few years, an autoimmune hypothesis for the pathogenesis of thrombotic thrombocytopenic purpura (TTP) has been proposed often, with variable success because of inconsistent supporting data. We are now aware that at least one subgroup of TTP patients does present with pathogenic autoantibodies (i.e, anti-ADAMTS13); this group consequently is a putative candidate for a curative treatment including plasma exchange (still the cornerstone of TTP treatment), together with corticosteroids or other immunosuppressants. Furthermore, for patients not responding to or relapsing following plasma exchange, the use of stronger immunosuppression (e.g., with the use of the anti-CD20 monoclonal antibody rituximab) should be considered as appropriate. Conversely, few data are actually available regarding the complex relationship between TTP and the antiphospholipid (aPL) syndrome, as well as other autoimmune diseases. Indeed, a correct differential diagnosis should be done on the basis of both different clinical presentations and autoantibody profile. At present, the presence of aPL antibodies should give evidence against a diagnosis of TTP, even though we cannot exclude that aPL antibodies may, in a minority of patients, be associated with a primary endothelial damage ultimately resulting in overt TTP.

An Early Unexpected Immune Thrombotic Thrombocytopenic Purpura Relapse Associated with SARS-CoV-2 Infection: A Case Report and Literature Review

“…We present a woman with a history of SLE and APLS, admitted with concurrent COVID-19 infection and acquired TTP. TTP has been described in association with SLE and APLS [ 4 , 5 ]. Considering the rarity and complexity of this case, we have yet to decipher whether CO­VID-19 was the triggering factor for TTP or whether these were 2 diseases occurring simultaneously.…”

The difficult distinction between antiphospholipid syndrome and thrombotic thrombocytopenic purpura

“…Plasma exchange is also a recommended treatment for the rare catastrophic form of APS where the abrupt multi‐organ failure presentation can mimic TTP clinically. In this context, the arguments made by Porta et al (2005) that a diagnosis of TTP should not be made in the presence of APL antibodies mentioned in the article have to be strongly supported. However, the measurement of ADAMTS13 in cases of APS associated with thrombocytopenia has its merits.…”

“…Secondly, the report demonstrates the difficulties in diagnosing TTP in complex presentations. TTP has been associated with other clinical conditions including autoimmune diseases, such as systemic lupus erythematosus (SLE), wherein a strong suspicion is necessary especially as many of these conditions can also cause low platelet counts with anaemia due to other reasons (Porta et al , 2005). In the present patient, one of the characteristic microscopic features of TTP, schistocytes, only appeared 2 days after the development of severe thrombocytopenia, and haemolytic anaemia stressing the need for persistent observance for this finding.…”

Concurrent thrombotic thrombocytopenic purpura and antiphospholipid syndrome: a rare and severe clinical combination

“…In one study (Amoura et al , 2004), two patients with a simultaneous clinical picture of TTP and APS with LA, anticardiolipin, anti ADAMTS13 antibodies and ADAMTS13 low levels, were described. This association is controversial, and recent articles have recommended against the diagnosis of TTP in the presence of aPL antibodies (Porta et al , 2005). Other reports, when aPL antibodies and microangiopathic thrombosis has been observed, have suggested that aPL antibodies could be a consequence of the endothelial damage, but not a cause of the disease.…”