Familial chronic B-cell malignancy. Hairy cell leukaemia in mother and daughter.

Two familial cases of hairy cell leukaemia are reported: a daughter, 44-years-old, with a very unusual ultrastructural pattern found in hairy cells, the "tubuloreticular inclusions", and her mother, 71-years-old, who was affected six years later. Routine laboratory investigations, cytochemical and cytogenetic studies including HLA typing, as well as in vitro proliferative response of peripheral blood mononuclear cells (PBMC) to polyclonal mitogens and to exogenous interleukin 2, were performed. The immunological characterization by assessing the cell surface phenotypic markers with monoclonal antibodies and transmission electron microscopy (TEM) investigations were also carried out. In case 2 all tests were performed both on PBMC and on the bone marrow cells. To the best of our knowledge this is one of the first reports of such familial association. The possibility that genetic factors might play a role in the etiology of leukaemia in man is discussed: in our two cases, however, cytogenetic studies did not support this, while HLA typing revealed a non-significant association of HCL with DQw3 allele. Alternatively, an environmental factor has been considered, and a viral infection-perhaps by a retrovirus of the HTLV family has been suggested as tubuloreticular inclusions have been found in both hairy cell leukaemia, as reported, by us, and AIDS-LAS. However, a long time elapsed between the manifestation of HCL in the daughter and in the mother, and as the two patients had not been living together at that time, the possibility of a viral transmission seems minimal. The results of TEM and of immunological investigations are presented and discussed. Both, but particularly the latter, support the B cell nature of the hairy cell.

Hairy cell leukemia with ultrastructural finding of 'tubuloreticular inclusions' in hairy cells: a possible marker of a virus-induced disease?

This report describes a case of hairy cell leukemia (HCL) with typical hematological and clinical findings. The most striking feature is the electron microscopic pattern of intracytoplasmic inclusions within hairy cells (HCs), which can be identified with the 'tubuloreticular inclusions', very unusual and not yet reported in HCL. The same structures were frequently detected in peripheral mononuclear cells from patients with acquired immune deficiency syndrome (AIDS) and with chronic lymphadenopathy syndrome (LAS), that are caused by the HTLV-III retrovirus. In the same patients elevated serum interferon levels were also found. The close relationship between tubuloreticular inclusions, viral infections and serum interferon levels suggests an etiologic association between a virus infection and outbreak of HCL. The results of our laboratory investigations also support a role for interferon in this disease.

Ultrastructural, immunological and clinical findings in two cases of hairy cell leukemia.

In two cases of hairy-cell leukemia were studied the transmission and scanning electron microscopy morphology, the cell surface markers with monoclonal antibodies and the response to polyclonal mitogens, the clinical course and staging. We have found in the hairy cells of both cases a characteristic membranous system consisting of several parallel cisternae arranged in series at regular intervals each bounded by a smooth membrane and interrupted at intervals by electron-dense structures: this structure can be identified with the 'annulate lamellae', as yet reported in many cells but never described in hairy cells. The results of immunological investigations are presented and discussed. Our data seem to support the neoplastic B lymphocyte nature of the hairy cells. Some interesting findings of the clinical course of the two patients are also stressed.