Alcoholism and Strongyloides stercoralis: Daily Ethanol Ingestion Has a Positive Correlation with the Frequency of Strongyloides Larvae in the Stools

It has been reported that Strongyloides stercoralis infection is more prevalent in chronic alcoholic patients than in non alcoholics living in the same country. In a retrospective study on the prevalence of S. stercoralis infection in a large sample of alcoholic patients, we demonstrate that this prevalence is significantly higher than in non-alcoholic patients admitted at the same hospital. Moreover, the frequency of the parasite was in close relationship with the daily amount of ingested ethanol, even in the absence of liver cirrhosis, reinforcing the idea that chronic alcoholism is associated with increased susceptibility to Strongyloides infection. Beside the bad hygiene profile of alcoholic patients, which explains high risk for acquisition of the parasite, the high prevalence of S. stercoralis in alcoholics may be in relationship with other effects of ethanol on the intestinal motility, steroid metabolism and immune system, which could enhance the chance of autoinfection and the survival and fecundity of females in duodenum. In this way, the number of larvae in the stools is higher in alcoholic patients, increasing the chance of a positive result in a stool examination by sedimentation method

Determinants of antigenic molecules responsible for genetically controlled regulation of immune responses.

The ability of mice bearing the H-2S haplotype to develop helper responses to the random copolymer of Glu,Ala while they developed suppressor responses to the terpolymer of Glu,Ala,Tyr suggested the crucial role of tyrosine in these peptides. On the basis of various considerations, it was postulated that many of the tyrosine residues in Glu,Ala,Tyr would be localized at the NH2-terminal end of the molecule. To verify this hypothesis, a block terpolymer composed of a short sequence of homopolymer tyrosine covalently bound to the random copolymer of Glu,Ala was synthesized. The present studies, using this block terpolymer, demonstrated that the chemical determinants stimulating helper and suppressor responses are distinct and can be present simultaneously in the same molecule. Thus, addition of COOH-terminal tyrosine residues to the Glu,Ala polypeptide converted this immunogenic molecule to an immunosuppressive molecule in mice bearing the H-2S haplotype. The mechanism by which these short sequences of tyrosine influence H-2-linked immune responses remains to be determined

Idiotypic analysis of monoclonal antibodies to poly(Glu60Ala30Tyr10).

Fifteen hybridoma anti-poly(Glu60Ala30Tyr10) (anti-GAT) antibodies were analyzed for the presence of a common set of idiotypic specificities associated with murine anti-GAT antibodies, termed CGAT idiotype, which are present on the anti-GAT antibodies of all mouse strains. Thirteen of these monoclonal anti-GAT antibodies expressed a major fraction of CGAT idiotypic specificities. However, the remaining fraction of CGAT idiotypic specificities were not detected in individual or pooled hybridoma anti-GAT antibodies. Anti-idiotypic antisera made against each of the 15 hybridoma anti-GAT antibodies preferentially bound homologous ligand and showed minimal binding activity to specifically purified serum anti-GAT antibodies. Furthermore, the diversity of the hybridoma anti-GAT antibodies was demonstrated by the presence of individual idiotypic specificities on each of the hybridoma anti-GAT antibodies. However, relatedness among some of the hybridoma antibodies was also apparent since idiotypic analysis revealed that some hybridoma anti-GAT antibodies shared cross-reactive idiotypic specificities not associated with CGAT idiotype. The genetic mechanisms which could account for the generation of such antibody diversity are discussed