Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

C3H mice (H-2 locus = k, hemoglobin D) received marrow cells intravenously following supralethal total-body x-irradiation. Donors were C3H, AKR (k, hemoglobin D), C57BR (k, hemoglobin S), A (a, hemoglobin D), and C57BL (b, hemoglobin S). Compatible marrow recipients suffered 20 % mortality. Incompatible H-2 and hemoglobin donation resulted in 97 % (mortality by the twenty-fifth day. H-2-compatible, hemoglobin-incompatible recipients suffered 67 % mortality by the fortieth day and then no further mortality. The H-2-incompatible, hemoglobin-compatible donation resulted in 36 % mortality by the fortieth day and showed continued mortality thereafter. Peripheral blood hematocrit and granulocyte counts and bone marrow cellularity and DNase activity revealed no significant differences, demonstrating successful grafts in all groups. However, the recovery of peripheral blood lymphocytes was inversely related to the mortality. Lymphopoiesis is apparently inhibited when the transplanted lymphocytes encounter overwhelming concentration of foreign antigens in the host. The H-2-compatible, hemoglobin-incompatible graft replaces the host's erythrocytes, thereby eliminating the inhibition of the graft's lymphocytic proliferation by that host antigen. During the first 40 days, homologous deaths result primarily from the effects of lymphopenia; thereafter, with recovery of lymphopoiesis, deaths are probably due to graft versus host reaction.
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PMID:Hematological response to isologous and homologous bone marrow transplantation: mechanism of homologous failure. 1738 24

A major goal for the treatment of patients with systemic lupus erythematosus with cytotoxic therapies is the induction of long-term remission. There is, however, a paucity of information concerning the effects of these therapies on the reconstituting B cell repertoire. Since there is recent evidence suggesting that B cell lymphopenia might attenuate negative selection of autoreactive B cells, we elected to investigate the effects of cyclophosphamide on the selection of the re-emerging B cell repertoire in wild type mice and transgenic mice that express the H chain of an anti-DNA antibody. The reconstituting B cell repertoire in wild type mice contained an increased frequency of DNA-reactive B cells; in heavy chain transgenic mice, the reconstituting repertoire was characterized by an increased frequency of mature, high affinity DNA-reactive B cells and the mice expressed increased levels of serum anti-DNA antibodies. This coincided with a significant increase in serum levels of BAFF. Treatment of transgene-expressing mice with a BAFF blocking agent or with DNase to reduce exposure to autoantigen limited the expansion of high affinity DNA-reactive B cells during B cell reconstitution. These studies suggest that during B cell reconstitution, not only is negative selection of high affinity DNA-reactive B cells impaired by increased BAFF, but also that B cells escaping negative selection are positively selected by autoantigen. There are significant implications for therapy.
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PMID:Enhanced selection of high affinity DNA-reactive B cells following cyclophosphamide treatment in mice. 2006 44