Secondary Antibody Deficiency in Glucocorticoid Therapy Clearly Differs from Primary Antibody Deficiency.
PURPOSE
The aim of this study was to identify characteristics of hypogammaglobulinemia secondary to glucocorticoid therapy and their value in the differential diagnosis to primary forms of antibody deficiency.


METHODS
We investigated prevalence and character of hypogammaglobulinemia in a cohort of 36 patients with giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) on glucocorticoid therapy in comparison to a gender- and age-matched cohort of hospital controls. We therefore determined serum immunoglobulin levels as well as B- and T cell-subsets in the peripheral blood of all participants. In addition, prior serum immunoglobulin levels and clinical data of the GCA and PMR patients were extracted from the electronic patient data-base.


RESULTS
21/36 GCA/PMR patients on glucocorticoid treatment developed antibody deficiency. In 19 patients this included IgG and in 13 patients IgG was the only affected isotype. The reduction of IgG was persistent in nearly 50 % of these patients during the observed period. GCA/PMR patients had reduced circulating naive and transitional B cells (p = 0.0043 and p = 0.0002 respectively) while IgM, IgG and IgA memory B cells were preserved. Amongst T-cell subsets, we found a reduction of CD4 memory T cells (p < 0.0001), CD4 regulatory T cells (p = 0.0002) and few CD8 memory T-cell subtypes.


CONCLUSION
Persistent humoral immunodeficiency occurs in about a quarter of GCA/PMR patients under glucocorticoid therapy. Because most patients have isolated IgG deficiency, preserved IgA production and class-switched memory B cells, by these markers this form of secondary hypogammaglobulinemia can be clearly distinguished from common variable immunodeficiency (CVID).
['Wirsum|Clemens|C|', 'Glaser|Cornelia|C|', 'Gutenberger|Sylvia|S|', 'Keller|Baerbel|B|', 'Unger|Susanne|S|', 'Voll|Reinhard E|RE|', 'Vach|Werner|W|', 'Ness|Thomas|T|', 'Warnatz|Klaus|K|']
D000361:Agammaglobulinemia D000368:Aged D000369:Aged, 80 and over D016175:B-Lymphocyte Subsets D005260:Female D013700:Giant Cell Arteritis D005938:Glucocorticoids D006801:Humans D007136:Immunoglobulins D008297:Male D008875:Middle Aged D011111:Polymyalgia Rheumatica D011241:Prednisone D015995:Prevalence D016176:T-Lymphocyte Subsets
Glucocorticoid Hypogammaglobulinemia Diagnosis Giant cell arteritis Common Variable Immunodeficiency