Recurrent Septic Arthritis with CVID and MGUS: A Chicken and Egg Conundrum
Saturday, March 5, 2016
South Exhibit Hall H (Convention Center)
Evan M. Atkinson, MD, Prathyusha Savjani, MD, Laurianne G. Wild, MD FAAAAI
Rationale: Common variable immunodeficiency (CVID) is associated with septic arthritis due to atypical bacteria such as Mycoplasma, Ureaplasma, and Chlamydia.  Per current criteria, the diagnosis of CVID requires exclusion of secondary causes of hypogammaglobulinemia such as monoclonal gammopathy of undetermined significance (MGUS).

Methods: Case report.

Results: A 48-year-old man has a 20-year history of recurrent culture-negative septic arthritis involving multiple joints.  Passive range of motion in his left knee is absent.  He has no artificial joints, indwelling intravenous (IV) catheters except those often placed for antibiotics, or other implanted devices.  He is HIV-negative and denies prior bacterial sinopulmonary infections.  His diabetes mellitus is well controlled on insulin.  CBC shows normocytic anemia, thrombocytosis, granulocytosis, and lymphopenia.  Other results include 510 CD4+ cells/µL, 124 CD8+ cells/µL (low), 5 CD19+cells/µL (very low), IgG 1295 mg/dL, IgA < 5 mg/dL (low), IgM 32 mg/dL (low), monoclonal IgG kappa band 850 mg/dL, and resultant non-clonal IgG 445 mg/dL (low).  Protective serotypes post-PPSV23 and subsequently PPV13 are, respectively, 0/14 and 3/11.  Tetanus and diphtheria titers are normal.  Evaluations in rheumatology, infectious disease, and hematology clinics have been negative.  Due to his laboratory results and significant history of recurrent infections, we initiated IgG replacement therapy and are following this patient closely.

Conclusions: Potential co-existence of CVID and MGUS presents a diagnostic challenge.  As our collective knowledge of CVID evolves, perhaps we can better define the immunologic relationship of CVID and MGUS.  Evaluation for monoclonal gammopathy should be considered in patients with a history concerning for humoral immunodeficiency.