Recurrent sepsis and seronegative arthritis in a patient with a selective IgG3 deficiency.

In a sixty-one-year-old patient with chronic polyarthritis, two life-threatening septic events were observed over a period of 6 months. The patient also had a selective IgG3 deficiency. The susceptibility to infection and chronic polyarthritis observed in this patient were very likely a consequence of the selective IgG3 deficiency.