Paradoxical effect of SARS-CoV-2 infection in patients with immune thrombocytopenia.

Thrombocytopenia has been identified as a common complication of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the general population. In an attempt to determine the impact of coronavirus disease 2019 (COVID-19) in patients with immune thrombocytopenia (ITP), a retrospective single-centre study was performed. Thrombocytosis was observed in patients with chronic ITP after SARS-CoV-2 infection, frequently needing treatment adjustment or even discontinuation of therapy. Relapses and newly diagnosed cases showed a fast response after initial treatment compared to ITP. Reduced immune activity due to lymphopenia during COVID-19 could explain this paradoxical effect, although further studies are needed.

Procoagulant profile in patients with immune thrombocytopenia.

Despite their low platelet count some immune thrombocytopenia (ITP) patients seldom bleed, indicating the presence of factors to compensate thrombocytopenia. Moreover, ITP patients may have an increased risk for thrombosis. These facts suggest the presence of procoagulant mechanisms that have not been clarified yet. The aim of this study was to identify these possible factors. Moreover, the utility of rotational thromboelastometry (ROTEM® ) to test haemostasis in these patients was also evaluated. Patients with ITP presented a procoagulant profile due to an increased amount of platelet- and red cell-microparticles, an increased resistance to protein C and the formation of a clot more resistant to fibrinolysis due to augmented levels of plasminogen activator inhibitor-1, which might reflect an endothelial damage/activation in ITP patients. Despite increased maximum clot firmness and reduced lysis, ROTEM® profiles showed a prolonged clotting time that might rely on the presence of anti-platelet antibodies as suggested by the increased lagtime in thrombin generation test caused by plasma from ITP patients on platelets from healthy controls. These results indicate the need to individualize therapeutic treatment for ITP patients, considering their procoagulant profile and the presence of concomitant risk factors. Moreover, ROTEM® appeared to be useful for evaluating haemostasis in ITP patients.