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Paroxysmal nocturnal hemoglobinuria: Test to monitor the action of eculizumab treatment
Author(s) -
Arcavi Miriam,
Ceballo Fernanda,
Caracciolo María Beatríz,
Lazarowski Alberto
Publication year - 2020
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/ijlh.13186
Subject(s) - eculizumab , paroxysmal nocturnal hemoglobinuria , cd59 , blockade , medicine , hemoglobinuria , immunology , complement system , antibody , gastroenterology , hemolysis , receptor
Abstract Introduction Paroxysmal nocturnal hemoglobinuria (PNH) is caused by a somatic mutation in the PIG‐A gene, which encodes for glycosylphosphatidylinositol, a phospholipid membrane that anchors proteins like CD55 and CD59. These proteins are inhibitors of the complement‐mediated lysis. PNH is diagnosed by flow cytometry, and treatment with eculizumab improves the life quality of patients with severe clinical compromise. The aim of this work was to evaluate a hemolytic test that allows monitoring the blockade of the alternative complement pathway caused by eculizumab (herein MET test). Methods There were analyzed a total of 163 serum samples from nine patients with PNH under treatment with eculizumab and ten healthy volunteers like controls. The patients were evaluated for 6 months. The MET test consisted in incubating red blood cells from patients (RBC PNH ) with either acidified serum from healthy volunteers and from patients with PNH. The results can be (a) Positive, (b) Blockade profile, or (c) Negative. Results Seven patients responded favorably to the eculizumab, and the test evidenced the blockade profile. The two remaining patients were nonresponders to the treatment, with a positive MET test. In these patients, the dose was increased. One responded favorably with a blockade profile, and the other continued to be nonresponder. Conclusions The MET test proved to be a useful tool to monitor the blockade of complement by eculizumab.