CD4 and chronic obstructive pulmonary disease: Included in these cases, one had acute myeloid leukemia (AML) and was on palliative chemotherapy, one had lymphoma and was receiving chemotherapy, one had acquired immune deficiency syndrome with low CD4 cell count, and six patients were receiving long-term (>1 month) systemic corticosteroid treatment for systemic lupus erythematosus (one case), polymyositis (one case), rheumatoid arthritis (two cases), chronic obstructive pulmonary disease (one case), and autoimmune hemolytic anemia (one case).