2 iga results of low 50's i have lupus, i experience swollen painful lymph nodes, painful breathing etc can low iga cause symptoms, what should i do?

No: This would not have accounted for your symptoms. Make sure you get a lung function test to find out whether asthma is the only cause for your breathing impairment . Another remote possibility is a drug reaction from the many drugs you have been taking to control your autoimmune disorder. If your rheumatologist can't help you, get a 2nd opinion.