Critical Aspects on Diagnosing IgG Subclass Deficiency and its Clinical Consequence

Publisher Summary Isolated IgG subclass deficiency has been recognized as a cause of undue susceptibility to infections in patients and guidelines for the clinical use of serum subclass determinations have recently been published by a WHO/IUIS working group. Although initially suggested to be associated with bacterial infections, various forms of IgG subclass deficiencies have now also been implicated in conjunction with viral disorders. To establish with certainty whether an immunoglobulin subclass deficiency is at all present in a given patient, access to proper reference sera, suitable anti-subclass reagents, and relevant age-matched control sera are required. If gammaglobulin replacement therapy is consequently instituted, knowledge on the subclass composition of the preparation given is needed as is knowledge on whether the route of administration chosen is sufficient in raising serum levels of the desired subclass