This literature marketed report as received from the author refers to a retrospective review of records of patients to identify Humoral immunodeficiency in patients presenting with Clinical features of systemic Lupus erythematosus. Methods: A retrospective review of records of patients seen between 2011 and 2014 with suspected humoral immunodeficiency and systemic lupus erythematosus (SLE) was undertaken. Records for review were identified using an electronic medical record search of diagnosis codes for SLE and hypogammaglobulinemia. The clinical and immunologic profile was determined for patients with confirmed or suspected SLE who also had undergone evaluation for humoral immunodeficiency. Hods. Results: The authors identified 36 patients meeting ACR criteria for SLE with inadequate response to pneumococcal vaccine challenge (failure to generate protective antibody titer to more than equal to 5/14 pneumococcal vaccine antigens) and/or low serum IgG levels (< 700 mg/dl) not attributable to antecedent immunosuppressive therapy. This comprised 5.5% of SLE patients meeting ACR SLE criteria in active follow-up. An additional 30 patients with SLE clinical features but not meeting SLE ACR criteria were identified with low serum IgG and/or inadequate vaccine responses. Among the 36 identified patients meeting ACR SLE criteria, serum immunoglobulin levels ranged from 459-744 mg/dl, 33 (92%) had serum IgG levels <700 mg/dl, while 19 (53%) had inadequate response to pneumococcal vaccine challenge, including the three patients with serum IgG > 700 mg/dl. Frequent upper/lower respiratory infections requiring antibiotic treatment (more than or equal to 3 episodes/year) were reported in 24/36 (67%) patients. SLE features developed 2-26 years (mean=8.9 years) prior to the recognition of low serum IgG in 25 (69%) patients, whereas initial SLE features were noted concurrently with or 3-4 years following first confirmed low IgG levels in 11 (31%). Arthritis (75%), photosensitivity (81%), malar rash (61%) and mucosal ulcers (56%) were the most prevalent SLE features. Only 9 (25%) of patients had low complement C3 or C4 levels, 6 (17%) had cytopenias, and 2 (6%) had elevated levels of anti-dsDNA. The majority of patients were managed with antimalarials (86%), with 8/36 (22%) also using methotrexate, 18/36 (50%) were on treatment with IVIG. Disease activity was low (SLEDA score less than or equal to 2) in 32/36 (89%) at the last noted follow-up assessment. This report refers to 19 of the 36 patients of unknown age and gender from the retrospective study. The concurrent condition of patient included suspected humoral immunodeficiency and SLE. On an unknown date, the patients were vaccinated with pneumococcal vaccine (manufacturer unknown) (dose/frequency and lot number not reported). The author reported that 19 (53%) of the 36 patients had inadequate response to pneumococcal vaccine challenge. The outcome of events was unknown. The causality of event was considered related to Pneumococcal Vaccine (manufacturer unknown). The author concluded stating SLE may be a presenting feature of patients with humoral immunodeficiency. Serum immunoglobulin levels and assessment of the response to pneumococcal vaccination for patients with low or low normal serum IgG levels should be included as part of the evaluation for suspected SLE, particularly in the context of frequent respiratory infections. Favorable outcomes are seen in the context of standard of care treatment for SLE combined with immunoglobulin replacement therapy. Additional information has been requested.