Hi!
The IgM levels could be high due to a recent infection—may be viral or a fungal infection. Also a recent stress like quitting smoking can raise the levels. Good job at quitting smoking! Stick to it! Once you get over this withdrawal phase, the IgM levels should fall back to normal. Meanwhile ask your doctor to treat your withdrawal symptoms so that you are not lured towards smoking again. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.
Also IGA and IGG a perfectly normal. I decided to have all bloodwork done because I quit smoking a week and a half ago and still feel horrible. I also had a nuclear stress test done and a ct with contrast about a week ago. Don't know if that matters.