What does low igg3 mean? i have constant infections, mrsa, yeast, uti

Immune deficiency: There are five classes of immunoglobulins: igg, iga, igm, igd, ige. The igg class of is composed of four different subtypes. Patients who lack, or have very low levels of, one or two igg subclasses, but whose other immunoglobulin levels are normal, are said to have a selective igg subclass deficiency, and this can lead to immune deficiency. See an immunologist or infectious diseases doctor.