Relevance of monoclonal antibody phenotyping and of genetic studies in the classification of T-cell leukemia/lymphoma.

In this short review we discuss two clinical entities characterized by the accumulation in the blood of mature lymphocytes bearing T-cell markers (formerly T-cell chronic lymphocytic leukemia or T-CLL). The lymphoproliferative disease of granular lymphocytes (LDGL) is characterized by the expansion of granular lymphocytes (GL). Clinically most patients have a benign clinical course, while some have neutropenia. The neoplastic or reactive nature of the disease is discussed. T-CLL with a T-helper phenotype is, on the other hand, an aggressive disease with poor survival. Patients may be classified into two subgroups according to the presence of serum antibodies against HTLV-I. The possible etiological role of HTLV-I in the disease is discussed.