Lactate dehydrogenase-linked immunoglobulin Akappa in a patient with nonimmune chronic idiopathic neutropenia

A 39-year-old patient with cervical cancer, stage Ia, was successfully treated by total hysterectomy. Then, after sustained neutropenia for more than 4 years and coincident with its exacerbation, the serum lactate dehydrogenase (LD) level started to elevate and reached a plateau. A test for antineutrophil antibody was negative and LD-3-linked IgAkappa, which may be responsible for high LD activity, was confirmed. The absolute number of blood NK cells was reduced, and a diagnosis of nonimmune chronic idiopathic neutropenia of adult was made. The successive occurrence of these 3 disorders may be based on interrelated immunological abnormalities.