Immunoglobulin isotype switching

IMMUNODEFICIENCY WITH HYPER-IGM (HIGMl), AN IMMUNOGLOBULIN ISOTYPE SWITCH DEFECT CHARACTERIZED BY ELEVATED CONCENTRATIONS OF SERUM IGM AND DECREASED AMOUNTS OF ALL OTHER ISOTYPES. AFFECTED MALES PRESENT AT AN EARLY AGE (USUALLY WITHIN THE FIRST YEAR OF LIFE) RECURRENT BACTERIAL AND OPPORTUNISTIC INFECTIONS, INCLUDING PNEUMOCYSTIS CARINII PNEUMONIA AND INTRACTABLE DIARRHEA DUE TO CRYPTOSPORIDIUM INFECTION. DESPITE SUBSTITUTION TREATMENT WITH INTRAVENOUS IMMUNOGLOBULIN, THE OVERALL PROGNOSIS IS RATHER POOR, WITH A DEATH RATE OF ABOUT 10% BEFORE ADOLESCENCE. 

Immunoglobulin isotype switching IgE production of anergic Th2 cells... 

Durdik, J., Gerstein, R.M., Rath, S., Robbins, P.F., Nisonoff, A., Seising, E. (1989). Isotype switching by a microinjected p immunoglobulin heavy chain gene in transgenic mice. Proc. Natl. Acad. Sci. USA 86,2346-2350. 

Kipps, T.J. Herzenberg, L.A. (1986). Homologous chromosome recombination generating immunoglobulin allotype and isotype switch variants. EMBO J. 5, 263-268. 

Liu, Y.J., Malisan, F., de Bouteiller, O., Guret, C., Lebecque, S., Banchereau, J., Mills, F.C., Max, E.E., Martinez-Valdez, H. (1996). Within germinal centers, isotype switching of immunoglobulin genes occurs after the onset of somatic mutation. Immunity 4,241-250. 

Snow RE, Djukanovic R, Stevenson FK Analysis of immunoglobulin E VH transcripts in a bronchial biopsy of an asthmatic patients confirms bias towards VH5, and indicates local clonal expansion, somatic mutation and isotype switch events. Immunology 1999 98 646-651. 

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