Would someone be willing to give me a list of diseases/conditions that can cause a positive IGM antibody test besides late stage Lyme Disease? I had Lymes 5 months ago and was treated and am still showing a positive Western Blot IGM but not IGG and a negative Elisa test. My symptoms: fatigue, achey, weak, headache, weight gain, left knee pain, racing heart (at times), coughing (little sputum), whistling when I breathe, etc.