T-cell chronic lymphocytic leukemia. Unusual morphologic, phenotypic, and karyotypic features in association with light chain amyloidosis.

BACKGROUND: Lymphocytes that display a phenotype of mature B-cells, T-cells, natural killer (NK) cells, or a combination of T-cells and NK cells can be found in patients with lymphoproliferations that manifest as expansions of peripheral blood lymphocytes (PBL). If these PBL expansions exhibit clonality, they can be classified as chronic lymphocytic leukemia (CLL). METHODS/RESULTS: A patient who had two simultaneous, clonal lymphoproliferative disorders manifested as an unusual T-cell CLL in conjunction with systemic light chain amyloidosis is described. Gene rearrangement studies of the PBL of the patient showed clonal rearrangements of both the T-cell receptor beta (T beta) chain and the immunoglobulin genes. Additional immunologic and microscopic studies of the T-cells of the patient showed that they were large, agranular, CD4+ T-cells that also expressed the NK cell marker CD57. Cytogenetics disclosed an unusual karyotype in the PBL. CONCLUSIONS: The pathogenesis of this T-cell CLL and whether it truly represents a malignant disorder, as well as its relation to amyloidosis, is discussed.

Solitary blood cultures as a quality assurance indicator.

For patients with suspected bacteremia, at least two separate blood cultures are recommended to achieve maximum sensitivity and to properly interpret results. Since a single blood collection may signify an improper procedure with serious consequences if the diagnosis of blood stream infection is missed, we investigated this problem with studies at three teaching hospitals (A, B, and C) and by a survey of 38 other hospitals. The incidence of solitary blood cultures ranged from 1 to 99% (median 26%) at the surveyed institutions. Among the cases investigated at hospitals B and C, between 10 and 30% of solitary blood cultures were not clinically indicated, while most of the others were caused by the physician not knowing that one culture was insufficient or by failure to complete the diagnostic plan. Focused concurrent intervention at hospital B was associated with reductions in solitary blood cultures from 40.0 to 24.6% (p = 0.045) and a decline in those not indicated from 38.1 to 12.5% (p = 0.192). Global educational efforts at hospital A were associated with a decrease in solitary blood culture rates from 52 to 37% (p = 0.016). These results show that blood culture practice varies widely among institutions in spite of consensus recommendations for proper specimen collections. We estimate that, nationwide, up to 18,000 etiologic diagnoses of bacteremia are missed annually because of this problem. Monitoring institutional solitary blood cultures is recommended as a test utilization indicator and as the basis for improving blood culture practice.

Expansion of large granular lymphocytes (natural killer cells) with limited antigen expression (CD2+, CD3-, CD4-, CD8-, CD16+, NKH-1-) in a human immunodeficiency virus-positive homosexual man.

Lymphoid neoplasms associated with acquired immune deficiency syndrome (AIDS) are mostly of B-cell type and rarely of T-cell origin. The authors report a case of a homosexual HIV antibody-positive, HTLV-1 antibody-negative man who developed T-lymphoproliferative disorder (TGLD) after he experienced a viral-like illness. The lymphoproliferative disorder was characterized by increased peripheral blood large granular lymphocytes (LGL) with azurophilic granules (natural killer [NK] cells) which had limited antigen expression: CD2+, CD3-, CD4-, CD8-, CD16+, NKH-1-. The LGL failed to express T-cell or T-cell-related antigens, with the exception of CD2. No functional or gene rearrangement studies were performed on the patient's lymphocytes. However, the results of immunophenotyping, including CD25, W26, and HLA-DR, were suggestive of an inactive state, and the negative finding for CD3 antigen was consistent with unarranged gene T-cell receptors. This is the first reported case of TGLD in an HIV antibody-positive patient.