Coexistence of IgA nephropathy and undifferentiated spondyloarthropathy in a female patient

We report a female patient with IgA nephropathy associated with undifferentiated spondyloarthropathy. The patient manifested proteinuria and microhematuria and was diagnosed as having IgA nephropathy based on the histopathologic findings of the renal biopsy. Two years later, the bone X-ray demonstrated syndesmophytes and multiple calcifications in the ligament and tendon insertions, suggestive of long-term enthesitis, but the patient had occasionally noticed mild lumbago up to the time she visited our hospital, with spontaneous pain in the bilateral shoulders and lower back. IgA nephropathy can be concomitant with a mild form of seronegative spondyloarthropathy in women. Possible association of this disorder should be carefully checked in patients with IgA nephropathy irrespective of clinical symptoms suggesting the arthropathy, particularly in women.