Immune status in two brothers with Omenn's syndrome: no discernible chimerism on FACS analysis using a monoclonal antibody specific for a maternally restricted HLA antigen.

Sequential immunologic examinations, including lymph node biopsies, in two brothers with clinical characteristics of Omenn's syndrome are presented in this study. Although the number of circulating T cells with mature phenotype (OKT3+, TCR1+) was within normal range, the lymphocyte proliferative response to mitogens was poor. Examinations of the lymph nodes revealed marked lymphoid depletion associated with eosinophilic infiltration and reticular cell proliferation. Over the clinical course of 5 months, circulating T cells also mostly disappeared. Thymic hypoplasia was noted at autopsy. Although intrauterine graft-versus host disease (GVHD) has been hypothesized as being the pathogenetic mechanism in this syndrome, maternal lymphocytes circulating in these patients were not identified either by karyotype and HLA typing or by highly sensitive FACS analysis and immunohistochemical studies using a monoclonal antibody, HLA-A9, specific for a maternally restricted HLA antigen, Aw24. In conclusion, the familial occurrence and the absence of maternal chimerism might be the essential features of Omenn's syndrome which should be differentiated from fetal GVHD.

Interleukin 3 enhanced interleukin 2-dependent maturation of NK progenitor cells in bone marrow from mice with severe combined immunodeficiency.

Human recombinant interleukin 2 (IL 2) and highly purified murine interleukin 3 (IL 3) were tested for their ability to generate NK activity in bone marrow cells from mice with severe combined immunodeficiency. IL 2 alone could dose dependently induce NK activity in marrow cells as determined by cytotoxicity against YAC-1 target cells. It was demonstrated that IL 3 had dual effects on the generation of NK activity in this culture system. The addition of IL 3 resulted in inhibition of NK cell activity seen at high concentrations of IL 2. In contrast, when IL 3 was added together with low concentrations of IL 2, the generation of NK cells as judged by cytotoxicity assay as well as the appearance of cells with NK phenotypes was markedly augmented. In some experiments, mice were treated with 5-fluorouracil (5-FU) to eliminate relatively differentiated NK precursors from bone marrow cells. It was noted that the residual immature marrow cells from 5-FU-treated mice showed little NK activity even after the culture with high concentrations of IL 2. Importantly, IL 3 could induce the generation of NK activity from 5-FU-treated marrow cells in the presence of IL 2. Kinetic studies indicated that NK activity was appreciably generated from 5-FU-treated marrow cells when preincubated with IL 3 at least for 12 hr and subsequently cultured with IL 2. The cells bearing IL 2 receptors appeared in 5-FU-treated marrow cells, even though cultured only with IL 3, which implied that IL 3 could support the development of very primitive NK cells from IL 2-unresponsive to IL 2-responsive states. These results suggested that IL 3 might play a crucial role for the IL 2-induced generation of NK cells in bone marrow through promoting the expression of IL 2R on NK progenitor cells.

Malignant clonal expansion of large granular lymphocytes with a Leu-11+, Leu-7- surface phenotype: in vitro responsiveness of malignant cells to recombinant human interleukin 2.

A 14-year-old Japanese female with neutropenia showed malignant proliferation of the large granular lymphocytes (LGLs). These LGLs were E rosette+ and Fc(IgG) receptor+ and therefore are referred to as T gamma lymphocytes. They were also Leu-11+ and OKT11+; however, they were clearly negative for Leu-7, OKT3, OKT8, OKM1, and HNK-1 antigens as well as for terminal deoxynucleotidyl transferase activity. Karyotype analysis revealed 47, XXX. The LGLs showed no rearrangement of T cell receptor C beta genes. The natural killer (NK) cell activity against K562 target cells was low, but was significantly augmented after stimulation by recombinant human interleukin 2 (IL 2) in contrast to minimal NK boosting by recombinant human gamma-interferon (gamma-IFN). Such a unique responsive ability to lymphokines was quite similar to that noted in fetal and cord blood cells. These LGLs also demonstrated a considerable increase in antibody-dependent cell-mediated cytotoxicity (ADCC) and lymphokine-activated killer (LAK) activity after a short incubation with IL 2. Although in a resting stage they showed no IL 2 receptor expression as examined by anti-Tac antibody, Tac antigen appeared after IL 2 treatment followed by a marked increase in 3H-thymidine incorporation and a remarkable production of gamma-IFN. To investigate the mechanism of neutropenia, in vitro IL 2-stimulated coculture studies of these cells with normal bone marrow cells were performed. Colony formation of myeloid progenitors (CFU-C) was significantly suppressed. In addition, the conditioned medium from IL 2-stimulated LGLs indicated a remarkable suppression of CFU-C. These results suggest that these LGLs with a Leu-11+, Leu-7- surface phenotype might belong to a unique subset of pre-NK cells that are functionally and phenotypically similar to those represented at any early stage of human ontogeny and that they strongly express Tac antigen under the influence of IL 2 administration, followed by remarkable cell proliferation and gamma-IFN production.

Efficacy of several plasma components in a young boy with chronic thrombocytopenia and hemolytic anemia who responds repeatedly to normal plasma infusions.

This report describes a patient with thrombocytopenia, microangiopathic hemolytic anemia, proteinuria, and microscopic hematuria that could be transiently improved by the infusion of plasma or various plasma components. An increase in platelet count following the transfusion of normal plasma was predictable and reproducible. In therapeutic trials with commercially available plasma components, factor VIII preparations were effective for inducing an increase in the platelet count and improving hemolytic anemia, but albumin, gamma-globulin, factor IX, and fibronectin preparations were ineffective. Serum from normal donors also relieved the symptoms of this condition in our patient. Partial plasma exchange (1,000 ml/m2 of body surface area) was performed with albumin instead of normal plasma, but there was no significant effect on platelet count or anemia. Large, multimeric von Willebrand factor components of the factor VIII complex (VIII/vWF) were found in the patient's plasma when his platelet count was normal, but their levels were reduced when the platelet count was decreased. The multimers of the patient's plasma were larger than those in normal plasma, but smaller than those in normal platelet lysate. Although the pathogenesis of this disease remains unknown, we conclude that transfusions of normal plasma, serum or factor VIII concentrate provide a factor that causes significant improvement in the thrombocytopenia and hemolytic anemia. Furthermore, large VIII/vWF multimers are possibly directly involved in pathogenesis of this disease.