Onkarappa Mangala Y, Sweeney JD. Influenza-associated thrombotic thrombocytopenic purpura: A report of two cases and a brief review of the literature.
Vox Sang 2021;
117:611-615. [PMID:
34841536 DOI:
10.1111/vox.13227]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/13/2021] [Accepted: 11/09/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVES
Thrombotic thrombocytopenic purpura (TTP) is often preceded by a recent history of an acute infection and influenza is the most implicated virus.
MATERIALS AND METHODS
We identified two cases of TTP, which were preceded by influenza between 2010 and 2021. In one patient, we epitope mapped the binding specificity of antibodies using an overlapping peptide approach of the stalk protein of Influenza B and the cysteine-rich spacer domain (CRSD) of ADAMTS13. A literature search was performed for reports of influenza-associated TTP over the period 1980-2021.
RESULTS
Two patients were identified in which TTP was preceded by influenza, one Influenza A and the other Influenza B. Epitope mapping of the latter's plasma identified target epitopes in both the stalk protein of Influenza B and CRSD of ADAMTS13. The literature review revealed only seven case reports, all but one from Europe or Asia and associated with Influenza A. Severe ADAMTS13 deficiency was demonstrated in only four cases.
CONCLUSION
We report the first small case series of influenza-associated TTP. Moreover, it is the first case implicating Influenza B and a mechanism favouring polyclonal B-cell proliferation rather than molecular mimicry as the stimulus to form anti-ADAMTS13 auto-antibodies is suggested.
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