Comparison of clinical performance of antigen basedenzyme immunoassay [EIA] and major outer membrane protein [MOMP]-PCR for detection of genital Chlamydia trachomatis infection

Background: Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen worldwide. Early detection and treatment of C.trachomatis genital infection prevent serious reproductive complications

Objective: Performances of enzyme immunoassay [EIA] and major outer membrane protein [MOMP]-polymerase chain reaction [PCR] for diagnosis of genital C.trachomatis infection in women were compared

Materials and Methods: In this cross sectional study a total of 518 women volunteers were included [33.67 +/- 8.3 yrs] who had been referred to Gynecology clinics of Qom province, Iran, were included. Endocervical swab specimens were collected to detect lipopolysaccharide [LPS] antigen in EIA and to amplify MOMP gene of C.trachomatis in PCR. Results were confirmed using ompI nested-PCR. Sensitivity, specificity, positive [PPV] and negative predictive values [NPV] were calculated for performance of the tests. Odds ratios were determined using binary logistic regression analysis

Results: In total, 37 [7.14%] cases were positive by EIA and/or MOMP-PCR. All discrepant results were confirmed by nested-PCR. Sensitivity, specificity, PPV and NPV values of EIA were 59.46%, 100%, 100% and 96.98%, and those of MOMP-PCR were 97.30%, 100%, 100%, 99.79%, respectively. Reproductive complications including 2.7% ectopic pregnancy, 5.4% stillbirth, 5.4% infertility, and 10.8% PROM were recorded. The risk of developing chlamydiosis was increased 4.8-fold in volunteers with cervicitis [p<0.05; OR 4.80; 95% CI 1.25-18.48]

Conclusion: C.trachomatis infection should be regarded in women of reproductive ages especially those with cervicitis. Primary screening of women by using the low cost antigen-EIA is recommended; however, due to the low sensitivity of Ag-EIA, verification of the negative results by a DNA amplification method is needed

[Phenotyping of peripheral memory T cell subsets in cutaneous leishmaniasis]

The heterogenous population of memory T lymphocytes is distinguished based on surface markers and effector functions such as cytokine secretion. Recently, two subsets of memory T cells are defined by expression of chemokine receptor CCR7 and CD45RA designating as "central memory" T cells [TCM] and "effector memory" T cells [TEM]. The objective of this study was to evaluate the phenotype and function of these lymphocytes in healed cases of cutaneous leishmaniasis. The phenotype of lymphocytes were determined in blood samples of 13 volunteers with history of self healing cutaneous leishmaniasis [HCL] and in 6 healthy controls. No significant difference was found in memory T cell subsets between HCL volunteers and healthy controls using flow cytometry. However, following sorting of different memory subsets, a significantly higher proliferation was seen in cells of HCL volunteers comparing to the control group. A significantly higher IFN-gamma response in TEM and a significantly higher IL-2 response in TCM were observed in cell culture of HCL volunteers comparing controls. The responses were elicited when the cells were stimulate with SLA in vitro, it is concluded Leishunania-specific TEM and Leishmania-specific TEM subsets exist in HCL volunteers and since the volunteers with history of CL presumed to be protected against reinfection, it seems that both TCM and TEM play role in the protection against Leishmania infection in these individuals

Evaluation of protectivity and immunogenicity of alum precipitated autoclaved Leishmania major vaccine mixed with Mycobacterium vaccae in the murine model of leishmaniasis

Leishmaniases represent a group of diseases caused by protozoan parasite of the genus Leishmania. Control strategies are not always effective, it seems that the sole control measure is to search for an effective vaccine. The objective of this study was evaluation of the rate of protection and immune response induction in Balb/c mice immunized with alum precipitated autoclaved Leishmania major [Alum-ALM] vaccine mixed with M. vaccae. Eleven groups of female 8-10 week old Balb/c mice were immunized subcutaneously [SC] three times, 21 days apart, with different doses of Alum-ALM mixed with different doses of either M. vaccae or BCG. The immunized animals and control group were challenged with 1 x 10 [6] L. major. Development and progression of leishmania infection were assessed by footpad swelling measurement at the site of challenge and parasite burden in lymph nodes. The immune responses of vaccinated animals were evaluated in vivo by leishmanin skin test [LST] and in vitro by measurement of cytokine [IFN-lamda and IL-4] levels in mononuclear cell culture] supernatants and titration of serum anti-leishmania antibodies [IgG and its sub-classes]. Footpad thickness measurment after challenge with live L. major showed no significant difference between immunized groups and control group. However, there were some prominent exceptional cases in the parasite burden titration in groups 1, 4, 6, and 8. Immunization with low dose of Alum-ALM mixed with M. vaccae or BCG induced IFN-lamda production, and diminished IL-4 level [in vitro], and caused a stronger LST response in a group that received BCG as an adjuvant. Mice that were immunized with high doses of Alum-ALM mixed with high doses of M. vaccae showed an increase in footpad thickness at the site of challenge and higher levels of IL-4 and IgGl. It seems that immunization of mice with a low dose of Alum-ALM mixed with M. vaccae as an adjuvant might induce a Thl type response. M.vaccae mixed with low dose of Alum-ALM has an inhibitory influence on the parasite burden in the infected tissues of mice. Also, BCG mixed with different doses of Alum-ALM induces a Thl immune response in Balb/c mice. Apparently, there is no significant difference in adjuvancity of BCG and M. vaccae. High dose of Alum-ALM mixed with high dose of M. vaccae induces a Th2 response