Secondary Immunodeficiency and Vaccine Response in Rheumatoid and Psoriatic Arthritis on Immunosuppressive Medicines

Abstract

BackgroundRheumatoid arthritis and psoriatic arthritis patients have dysregulated immune system parameters that may increase infection risk at baseline. In addition, treatment of these conditions with immunosuppressive medications may lead to the development of secondary immunodeficiency (SID). Our objective was to assess SID in a cohort on immunosuppressive medications. We hypothesized that SID is clinically detectable by assessing immune parameters and polysaccharide and protein-based vaccination responses. MethodologyA prospective cohort study of 42 subjects on immunosuppressive medications was assessed. Analysis included immunoglobulin levels, lymphocyte subsets, and two-step response to diphtheria, tetanus, and 23valent Streptococcus pneumoniae vaccinations. Exclusions included primary immunodeficiency, malignancy, pregnancy, neutropenia, immunoglobulin replacement, prior B-cell-depleting medication or chemotherapy, use of non-immunosuppressive medication, or recent use of glucocorticoids. Suboptimal vaccine response was defined as an abnormal response based on standard criteria for each vaccine. ResultsLow IgM levels (below 50 mg/dL) occurred in seven (17%) subjects and IgG (below 650 mg/dL) in three (7%) subjects. Impaired lymphocyte subsets were uncommon. In total, 33 (78%) subjects completed the two-step vaccination assessment. Overall, 29 of 33 (88%) subjects demonstrated suboptimal response to pneumococcal vaccination, 10 (30%) demonstrated suboptimal response to diphtheria, and four (12%) to tetanus. Two (6%) subjects demonstrated suboptimal response to all vaccinations. Finally, 31 (94%) subjects demonstrated suboptimal response to at least one vaccination. ConclusionsSID may develop, is clinically detectable, and most notably demonstrated in suboptimal responses to polysaccharide vaccinations, especially against S. pneumoniae.