Erythrophagocytosis in Autoimmune Immunoglobulin A-Mediated Hemolysis

Authors

Jahnavi Gollamudi
Swapan Kumar Dasgupta
Perumal Thiagarajan

Publication Date

9-5-2023

Journal

Transfusion

DOI

10.1111/trf.17532

PMID

37668082

PMCID

PMC10655130

PubMedCentral® Posted Date

10-1-2024

PubMedCentral® Full Text Version

Author MSS

Published Open-Access

yes

Keywords

Humans, Anemia, Hemolytic, Autoimmune, Immunoglobulin A, Hemolysis, Autoantibodies, Erythrocytes, Immunoglobulin G, Lymphohistiocytosis, Hemophagocytic, Coombs Test, hemolysis, IgA antibodies, autoimmune, trogocytosis, phagocytosis

Abstract

INTRODUCTION: Warm antibody-mediated autoimmune hemolysis (WAIHA) is most often due to immunoglobulin G (IgG) antibodies and is detected by direct antiglobulin test (DAT). However, about 10% cases of hemolytic anemia are DAT negative. Herein, we describe a patient with DAT-negative hemolytic anemia due to an anti-IgA antibody. We investigate if isolated IgA can promote erythrophagocytosis.

METHODS: We isolated patient and control IgA on Jacalin agarose. Isolated IgA was used to sensitize healthy ABO/Rh-matched donor red blood cells (RBC). Antibody binding was examined by flowcytometry. The effect of IgA on erythrophagocytosis was evaluated using Macrophage colony stimulating factor 1 (M-CSF)-differentiated autologous macrophages by Giemsa staining and immunofluorescence microscopy.

RESULTS: We show that isolated IgA from the serum can bind to red cells. In addition, RBCs were phagocytosed efficiently by autologous macrophages in the presence of patient IgA.

CONCLUSION: Our results show that IgA antibodies are capable of inducing erythrophagocytosis like IgG antibodies in the absence of complement fixation.