RESUMO
BACKGROUND: Giardia lamblia is one of the most important intestinal parasites. The aim of this study was to measure serum levels of IgA, IgE, zinc, copper, vitamin B12 and folate in individuals with giardiasis in comparison to normal subjects. METHODS: The study was carried out among 49 Giardia positive and 39 age and sex matched healthy volunteers. Examination of stool samples was done by direct wet smear and formol-ether concentration method. Serum samples were obtained for further laboratory examination. IgA levels were measured by Single Radial Immune Diffusion (SRID). IgE levels were measured by ELISA kit. Zinc and copper levels was measured by Ziestchem Diagnostics Kit and colorimetric endpoint-method respectively. Vitamin B12 and folate levels were measured by DRG Diagnostics Kit and Enzyme Immunoassay method respectively. All data were analyzed using SPSS version 17. RESULTS: There was a statistically significant difference in IgA, IgE, copper and zinc levels between positive and negative groups (P<0.05). There was no significant difference between vitamin B12 and folate levels between the two groups. Mean values of Giardia positive and negative groups for IgA were 309.26 and 216.89 mg/dl, IgE 167.34 and 35.49 IU/ml, copper 309.74 and 253.61 µg/dl and zinc 69.41 and 144.75 µg/dl respectively. CONCLUSION: The results showed levels of IgA may correlate more closely with giardiasis than IgE. Regarding trace elements, giardiasis elevated serum copper levels, while it decreased serum zinc. Finally, there was no significant difference in serum levels of vitamin B12 and folic acid between the two groups.
RESUMO
Although the presence of antibodies against double-stranded (ds) DNA is highly specific of systemic lupus erythematosus (SLE), it is not detected in all SLE patients, perhaps due to a lack of sensitivity of the tests routinely used to assay anti-(ds) DNA. Looking for an alternative assay, this study explored the applicability of a DNA-mobility shift assay for the detection of anti-(ds) DNA; furthermore, the study compared the use of Salmonella typhimurium DNA with that of calf thymus DNA in the assay. After electrophoresis, samples containing S. typhimurium DNA and IgG from SLE sera showed marked alterations in DNA electrophoretic mobility when compared to DNA alone. In our sampling, SLE patients who tested negative for anti-(ds) DNA antibodies with routinely used assays such as Crithidia luciliae immunofluorescence test, radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA), tested positive for anti-(ds) DNA with the DNA mobility shift assay using S. typhimurium DNA. Incubation with IgG from control sera in the same proportions as above did not affect S. typhimurium DNA electrophoretic mobility. When S. typhimurium DNA was replaced by calf thymus DNA, the effect on the DNA mobility was less pronounced and less reliable. These results indicated that a DNA-mobility shift assay would be a useful alternative for the unequivocal detection of abnormal titers of anti-(ds) DNA antibodies. Furthermore, data indicated a greater ability of the IgG from SLE patients to form complexes with S. typhimurium DNA than with calf thymus DNA, suggesting an alternative testing DNA which may lead to a more sensitive anti-(ds) DNA detection.
