Altered Distribution of Peripheral Blood Maturation‐Associated B‐Cell Subsets in Chronic Alcoholism

BackgroundAlthough decreased counts of peripheral blood (PB) B cellsassociated with an apparently contradictory polyclonal hypergammaglobulinemiahave been reported in chronic alcoholism, no information exists about the specific subsets of circulating B cells altered and their relationship with antibody production. Here, we analyzed for the first time the distribution of multiple maturation-associated subpopulations of PB B cells in alcoholism and its potential relationship with the onset of liver disease. MethodsPB samples from 35 male patients20 had alcoholic hepatitis (AH) and 15 chronic alcoholism without liver disease (AWLD)were studied, in parallel to 19 male healthy donors (controls). The distribution of PB B-cell subsets (immature/regulatory, naive, CD27(-) and CD27(+) memory B lymphocytes, and circulating plasmablasts of distinct immunoglobulinIgisotypes) was analyzed by flow cytometry. ResultsPatients with AH showed significantly decreased numbers of total PB B lymphocytes (vs. controls and AWLD), at the expense of immature, memory, and, to a lesser extent, also naive B cells. AWLD showed reduced numbers of immature and naive B cells (vs. controls), but higher PB counts of plasmablasts (vs. the other 2 groups). Although PB memory B cells were reduced among the patients, the percentage of surface (s)IgA(+) cells (particularly CD27(-)/sIgA(+) cells) was increased in AH, whereas both sIgG(+) and sIgA(+) memory B cells were significantly overrepresented in AWLD versus healthy donors. Regarding circulating plasmablasts, patients with AH only showed significantly reduced counts of sIgG(+) cells versus controls. In contrast, the proportion of both sIgA(+) and sIgG(+) plasmablastsfrom all plasmablastswas reduced in AH and increased in AWLD (vs. the other 2 groups). ConclusionsAH and AWLD patients display a significantly reduced PB B-cell count, at the expense of decreased numbers of recently produced immature/regulatory B cells and naive B cells, together with an increase in Ig-switched memory B lymphocytes and plasmablasts, particularly of IgA(+) cells.