Iron -overload regulatory effect on cytokine production by spleen lymphocytes in munine cryptosporidiosis the modulatoncy potential potential of iron chelation therapy on immunity

Iron-overload both aggravates the outcome of infections caused by a variety of microorganisms and exerts subtle effects on immune status by altering the proliferation of T and B cells. The effect of iron-overload on the type of T helper [Th] immunity elicited and the subsequent effect on the susceptibility, course and outcome of Cryptosporidium parvum infection were investigated in the present study. Separate groups of iron-overloaded [40 mg of iron dextran/kg intraperitoneally every other day for 4 weeks before infection] immunocompetent and immunocompromised mice were either infected or infected and received iron chelator [deferoxanime: DFO. 50 mg/kg intraperitoneally every other day from the day of infection]. Spleens were harvested and an enzyme linked immunosorbent assay [ELISA] was performed on spleen culture supernatants for in vitro analysis of interferon-gamma [IFN-gamma] and interleukin [IL]-4. Iron-overload induced a Th2 cytokine response with significantly higher IL-4 and lower IFN-gamma levels compared to infected non- treated control. The infection rate was 100% and the infection was severe and persistent in both immunocompetent and immunocompromised iron-overloaded mice with death of all immunocompromised mice. Iron chelation by DFO enhanced the production of Th1 anticryptosporidial immunity [significantly higher IFN-gamma compared to infected non- treated control] limiting the severity and clearing the infection in iron-overloaded immunocompetent mice [cure rate 100%] and controlling the infection in immunocompromised mice with cure rate 30%, percentage reduction in oocyst shedding 80.8% and mortality rate 10% at the end of the experiment [30 days post infection]. These data indicated that iron-overload negatively affected Th1-mediated immunity in mice with cryptosporidiosis thus altering the susceptibility, course and outcome of infection. Iron-overload represents a risk factor for flaring up of Cryptosporidium parvum infection in absence of any obvious immunosuppressive conditions; hence successful therapy in iron-overloaded hosts depends mainly on iron chelation. The immunomodulatory properties of DFO were elucidated in terms of restoring Th1 immunity in iron-overloaded mice

Bacterial contamination and endotoxin production in the water treatment system for hemodialysis

The present study aimed to assess bacterial contamination and endotoxin production in water treatment system for hemodialysis. It also aimed to evaluate the efficiency of decontamination measures applied along the water pathway in the system. The study was conducted in the water treatment system of Pediatric Dialysis Unit, Children's Hospital, Ain-Shams University. Samples were examined for four consecutive weeks after changing the bacterial filter; three samples were collected at each week. One sample was taken from tap water [sample A], another sample was taken from treated water just after the bacterial filter [sample B] and the third sample was taken from water in the returning pipe system not used by the hemodialysis machines [sample C]. Quantitative methods were used for the total count of viable heterotrophic microorganisms [denoting bacterial contamination], total coliforms, fecal coliforms, Enterococci, Pseudomonas spp. and the sulfite-reducing Clostridia [denoting fecal contamination]. The samples were assayed for endotoxin by the limulus amebocyte lysate [LAL] kit, employing a GEL-CLOT LAL. It is a qualitative non-kinetic assay

Study of the high prevalence of HCV in Egypt

The correlation of schistosomiasis and other variables as a risk factor behind the remarkable high rates of HCV seropositivity in Egypt was studied by examining the sera of 188 subjects [94 apparently healthy villagers and 94 non professional blood donors] for Schistosoma antibodies by Falcon assay screening test enzyme linked immunosorbent assay [FAST-ELISA] and for HCV antibodies by the application of screening [ELISA] and confirmatory [RIBA] techniques The results showed that the overall prevalence of HCV antibodies was 29.8% by ELISA reduced to 21.8% i.e. 73.2% confirmation by RIBA test. HCV-RNA [HCV viraemia] was detected in 76% of 25 ELISA anti-HCV positive sera by P.C.R. technique. After adjustment for age, there was no statistical significant correlation between the remarkable high rates of HCV seropositivity in Egypt and risk factors studied other than blood transfusion, and schistosomiasis

Hepatitis C virus infection in blood donors in Egypt

A study was carried out on 90 serum samples from non-professional blood donors to find out the relative prevalence of HBV and HCV among those blood donors. Results demonstrated overall positivity rate of 14.4% for anti-HCV by RIBA test. The percentage of reactive sera was 6% for the age group of 20 to below 30 years, and 37.5% in those aged above 30 years, and this difference was statistically significant. Considering the combined reactivity of the tested 90 sera for anti-HBs and anti-HCV, the results showed that 41.1% of the sera were positive for anti-HBs; 10% reacted positively with both anti-HBs and anti-HCV, and 4.4% of the sera were positive for anti-HCV only. The high prevalence of anti-HCV in this study [14.4%] exceeds that reported in other countries, and is comparable with that of Saeed and associates [1991]. These results may indicate endemicity of HCV in Egypt and/or a possible role of the endemic schistosomiasis. On the basis of data, suggesting that anti-HCV reflects persistent infection rather than immunity, screening for anti-HCV should be included in all blood transfusion services to exclude HCV which is responsible for 90% of PTH [Van der Poel et al., 1990; Weiner et al., 1990; and Esteban et al., 1991].The remarkably high seroprevalence of anti-HCV among Egyptian volunteer blood donors, which has not so far been reported from other countries, should be thoroughly studied. This should cover many aspects including large epidemiological studies, factors pertinent to Egypt as schistosomiasis, and other possible factors that might enhance HCV transmission in Egyptian population. High risk groups as the polytransfused and renal dialysis patients should be studied. Needless to say that, an accurate measure of HCV prevalence depends on specificity and sensitivity of the employed laboratory diagnostic tests; development of new tests for the detection of antibodies to HCV, together with development of tests for other markers such as HCV antigen and the polymerase chain reaction to detect HCV DNA in blood, will be of great help