Abstract • 172

A twenty year old white female with FMF and a long standing history of repeated upper respiratory tract infections (URI) since childhood required protracted antibiotics. Immunologic evaluation revealed the following values: IgG 1200 mg/dl, IgA 50 mg/dl, IgM 150 mg/dl, IgG1 895 mg/dl (nl 422-1292), IgG2 343 mg/dl (nl 117-747), IgG3 29.9 mg/dl (nl 41-129), IgG4 46.9 mg/dl (nl 1-291). Although specific antibody to pneumococcus was normal there was a reduction in specific antibody to diphtheria (<0.2 IU/mL). Because the occurrence of infection seemed to trigger attacks of FMF and also the presence of an IgG3 subclass deficiency, the patient was started on a monthly course of IVIG infusion (400mg/kg) over the past 8 months. With this therapy there has been a marked reduction in URIs and her attacks of FMF have been significantly diminished. This case represents the first description of the occurrence of FMF and IgG3 subclass deficiency and illustrates the importance of identifying immunologic factors which might influence other genetic disorders.