Transient low level of IgG3 induced by sepsis

Staphylococcus aureus sepsis developed in a 14 year old girl. Immunological evaluation revealed low level of IgG3, although total IgG level was normal. The level of IgG3 increased gradually along with the recovery from sepsis. Immunoglobulin replacement therapy might have been useful in this patient, even though the total immunoglobulin level was within normal limits.