After months of misdiagnoses, Tom Heisler found answers at Mayo Clinic, where advanced renal pathology revealed IgG4-related disease and led to his recovery.
After his third COVID-19 infection, Arkansan Tom Heisler developed a persistent cough. Then came profound weight loss, blurred vision, and unsteadiness of gait. Local specialists misdiagnosed him with lung infections such as cryptococcal pneumonia, but antibiotics and oral antifungal medications failed to help.
Tom grew weaker and could barely walk. With his survival at risk, he and his family came to Mayo Clinic in Rochester, Minnesota. By now, Tom also suffered from kidney dysfunction, swollen lymph nodes, and lesions on his lungs, symptoms inconsistent with his previous pneumonia-related diagnoses.
“Tom’s illness involved several organs, including the lungs, kidneys, parotid (salivary) glands, and lymph nodes, which indicated a systemic rather than localized process,” says Mayo Clinic nephrologist Wisit Cheungpasitporn, M.D.
After initial testing ruled out additional diseases like lupus and myeloma, Tom’s Mayo Clinic care team began to suspect he was suffering from IgG4-related disease (IgG4-RD). IgG4 (immunoglobulin G4) helps regulate the immune system. However, when this antibody becomes elevated, IgG4-positive plasma cells infiltrate affected tissues, causing scarring that can lead to organ enlargement or dysfunction. IgG4-RD often mimics infections, cancers, and other autoimmune diseases. For this reason, it requires a high level of clinical suspicion, advanced renal pathology expertise, and coordinated diagnostic evaluation.
IGG4-RD TESTING
Because IgG4-RD often mimics infections, cancers, and other autoimmune diseases, it requires a high level of clinical suspicion and coordinated diagnostic evaluation. Mayo Clinic Laboratories specializes in renal pathology, offering two tests that detect IgG4-related disease: the Immunoglobulin Subclass, IgG4 (Mayo ID: IGGS4), and IgG Subclasses (IgG1, IgG2, IgG3, IgG4) (Mayo ID: IGGS). Both tests are available as part of Mayo Clinic Laboratories’ comprehensive diagnostic portfolio for IgG4-related disease.
After a series of additional tests at Mayo Clinic, Tom’s nephrology team ordered a kidney biopsy, which provided a diagnostic breakthrough and confirmed IgG4-positive plasma cell infiltration—consistent with IgG4-RD. This confirmation was made possible by two specific tests developed and validated by Mayo Clinic’s Department of Laboratory Medicine and Pathology: Immunoglobulin Subclass, IgG4 (Mayo ID: IGGS4), and IgG Subclasses (IgG1, IgG2, IgG3, IgG4) (Mayo ID: IGGS).
Once Tom had a clear, definitive diagnosis, he received corticosteroid treatment and, within weeks, felt like a new man.
“Any doctor can treat a condition. It’s the diagnosis that counts, and Mayo Clinic is the best diagnostic place in the world,” Tom says.
Read the rest of Tom’s remarkable story, including his video testimony, here.
