Establishment and characterization of an amylase-producing human myeloma cell line.

Two stable lines of IgA lambda-producing plasma cells (KHM-1A and KHM-1B) that were free of the Epstein-Barr virus were established from a patient with multiple myeloma complicated by hyperamylasemia. Surface marker studies of the two cell lines showed that the cells had no surface immunoglobulins but were positive for cytoplasmic immunoglobulins (IgA lambda) and for HLA-DR and PCA-1. Secretion of IgA monoclonal immunoglobulin by the two lines was detected by a plaque-forming cell assay and by an enzyme-linked immunosorbent assay of culture media. KHM-1B cells also secreted alpha-amylase, but no such activity was detected in the culture-conditioned supernatant fluid of KHM-1A.