Does anyone know much about immunoglobulin levels? A blood test a few weeks ago showed that my levels are just below the normal level. I’ve had 7 courses of antibiotics this year. Could the low level be caused by the antibiotics? I looked up immunotherapy, and one US article said the treatment isn’t particularly successful. I’d rather not have the treatment, but could it help me fight infections better? I’d also rather not have antibiotics. I’m asking on here as I find that I need to be armed with information as a patient so that I can advocate myself. My antibiotics were for chest infections, a sinus infection and bacterial vaginosis (probably caused by the antibiotics). I probably currently have both a chest infection and a sinus infection.