Cytomegalovirus-induced interstitial pneumonitis in a patient with systemic lupus erythematosus

We report an unusual case of cytomegalovirus (CMV) interstitial pneumonitis (IP) occurring in a 51-year-old Japanese woman with systemic lupus erythematosus (SLE). She developed hypoxemia after intensive immunosuppressive therapy with prednisolone and cyclophosphamide. Fine crackles were audible in the lower lungs bilaterally. Chest X-ray and computed tomography confirmed the presence of IP. CMV-antigenemia was confirmed by immunological staining of leukocytes using the peroxidase-labeled monoclonal antibody, HRP-C7. Hypoxemia improved gradually on methylprednisolone pulse therapy and gancyclovir, and CMV-antigen positive leukocytes disappeared from the peripheral blood. Data suggest the importance of CMV as a cause of IP in SLE, and the usefulness of the assay for CMV-antigenemia with C7-HRP for rapid diagnosis.