Characterization of the lymphoproliferative diseases in the skin by DNA analysis

Various samples from lymphoproliferative diseases in the skin were analyzed by Southern blotting technique with probes from the T cell receptor gene, immunoglobulin genes, and human T cell leukemia virus-I genome. Samples were taken from 10 mycosis fungoides (MF) patients, 1 parapsoriasis en plaque patient, 10 Adult T cell leukemia/lymphoma (ATL) patients, 1 cutaneous T cell lymphoma (CTCL) patient, 4 lymphomatoid papulosis (LP) patients, 4 B cell lymphoma patients, and 2 actinic reticuloid (AR) patients. In MF, the monoclonality of the T cells became detectable first in the skin when plaques develop to tumors then in lymph nodes, and finally in the blood lymphocytes, indicating this disease develops from local (skin) malignancy to systemic malignancy. In parapsoriasis en plaque, no monoclonality was detected in any sample. We could distinguish cutaneous ATL from the carrier state by detecting the T cell monoclonality and HTLV-I integration with these probes. One patient with CTCL showed detectable T cell monoclonality; 1 out of 4 patients with LP did the same. Four samples from patients with B cell lymphoma revealed detectable monoclonal rearrangement of immunoglobulin heavy and light chain genes. In AR, no monoclonality was detected in any sample. From these data, we conclude that DNA analysis is useful in determining the monoclonality, cell origin, and distribution of monoclonal cells from skin samples.