Coexistent IgG2 and IgA deficiencies in blood donors.

BACKGROUND

To meet the transfusion requirements of IgA-deficient patients with anti-IgA, blood services screen random donors to identify potential donors of IgA-deficient blood components. New information reveals that some IgA-deficient persons may also be deficient in IgG2 and may be at increased risk for bacterial infections.

STUDY DESIGN AND METHODS

Serum samples from IgA-deficient blood donors and patients were tested for IgG2 concentration by radial immunodiffusion using monospecific anti-IgG2.

RESULTS

Four (9.0%) of 44 IgA-deficient blood donors and 14 (31.5%) of 44 IgA-deficient patients had coexistent IgG2 and IgA deficiencies. Follow-up interviews with the 4 donors who had coexistent IgG2 and IgA deficiencies revealed that 3 had recurrent respiratory infections and had been hospitalized at least once for pneumonia. The fourth donor did not report a history suggestive of recurrent infections.

CONCLUSION

Some blood donors, recruited specifically because they are IgA deficient, may also be deficient in IgG2. Persons identified by donor screening programs as being IgA deficient should be tested for IgG2. If deficient in IgG2, they should be evaluated for a history of recurrent bacterial infections and counseled accordingly.