INTRODUCTION. X-linked agammaglobulinemia is an inborn error of immunity characterized by virtually no serum levels of immunoglobulins. Its presentation is infrequent in our country. Clinical characteristic of suspicion are recurrent infections; although definitive diagnosis requires a genetic study, it can be suspected with low or absent immunoglobulin levels and flow cytometry.
PRESENTATION OF THE CASE. A 6-year-old male with complete immunizations had history of maternal aunt who died at one year of age of unknown cause, without history of other premature or male deaths. He began with right elbow and left shoulder inflammation in January 2017 with diagnosis of septic arthritis with resolution after antibiotic treatment, 2 months later articular elbow inflammation repeated and an autoimmune process was suspected. Blood culture was positive for Streptococcus pneumiae, requiring antimicrobial treatment, surgical irrigation and debridement. Consultory to our service was asked. Laboratory results: Hb 11.4 g/dl, Hto 36%, leukocytes 22,960 ml, neutrophils 18,070 ml, lymphocytes 3960 ml, platelets 1,370,000 ml, HIV test (-). Immunoglobulins and serial flow cytometry: IgA 26.6 mg/dl (33-202 mg/dl), IgM 18 Mg/dl (48-202 mg/dl), IgG 134 mg/dl (633-1280 mg/dl), CD3+ 91.49% (62-69%), CD3+ 2152 (1800-3000), CD8+ 30.6% (25-32%), CD8 721.2 (800-1500), CD4+ 57.3% (30-40%) CD4+ 57.7% (30-40%), CD19 0.1% (21-28%) Cd19+ 2.3 (700-1300). Due to lack of B lymphocytes and low immunoglobulins levels agammaglobulinemia was diagnosed and replacement treatment with1g/kg//monthly immunoglobulin was started for 3 months, finding clinical improvement, with adequate levels of IgG. Due to lack of resources in our institution for substitution, the patient was referred to tertiary care.
DISCUSSION. Arthritis present in X linked agammaglobulinemia is usually a one-time septic monoarthritis (22%). Symmetric polyarthritis with occasional extra-articular manifestations resembling non-septic pauciarticular rheumatoid arthritis can also be observed(1,2). Recurrent septic poly-arthritis is not frequent.