Frequency of hepatitis B virus DNA in anti-HBc positive, HBsAg negative blood donors in Rasht, northern Iran

Background

One of the important factors in the ensuing safety of blood transfusion is to use a sensitive screening assay for detection of blood-born infective agents such as HBV which transmits through transfusion. To improve the detection rate of HBV infection in blood donors, a cross-sectional study was conducted in Rasht, which is the largest city in the north of Iran to explore the possibility of using anti-HBc as a screening test.

Study design and methods

A total of 2041 blood samples negative for HBsAg, Anti-HCV, Anti-HIV I, II and RPR were tested to detect anti-HBc and then the positive anti-HBc samples were further checked for the presence of HBV DNA.

Results

The prevalence of anti-HBc positive samples was 3.8% and HBV DNA was detected in only one sample.

Conclusions

This study showed that anti-HBc positive blood donors may be a source of HBV transmission and further study for evaluation of HBV DNA in anti-HBc positive blood units is needed.     

Immune response and protection assay of recombinant major surface glycoprotein of Leishmania (rgp63) reconstituted with liposomes in BALB/c mice

In this study the ability of recombinant gp63 entrapped in liposomes to induce immune response and protection against L. major infection in susceptible BALB/c mice was studied. Liposomes containing rgp63 (Lip-rgp63) were prepared from egg lecithin and cholesterol using detergent solubilization method. Immunization of BALB/c mice with rgp63 alone conferred a partial protection while entrapment of rgp63 in liposomes significantly increased the rate of protection (P<0.05). The parasite burden of spleen in mice challenged with L. major was significantly (p<0.001) lower in group of mice immunized with rgp63 alone or Lip-rgp63, however, the least parasite burden was seen in Lip-rgp63 group. Both rgp63 alone and Lip-rgp63 elicited significant delayed-type hypersensitivity (DTH) response compared to controls (p<0.01), however, the DTH response of PBS-rgp63 was less than the Lip-rgp63. Titration of anti-Leishmania IgG isotypes (IgG2a/IgG1) showed a preferential Th1 type of immune response only in mice immunized with Lip-rgp63. The results indicate that liposomes might be used as a suitable immunoadjuvant for development of Leishmania vaccine.     

Immune response measured in human volunteers vaccinated with autoclaved Leishmania major vaccine mixed with low dose of BCG

The immune responses induced against Leishmania antigens in volunteers who were vaccinated in a double-blind, randomized field efficacy trial of a preparation of autoclaved Leishmania major (ALM) mixed with a low dose of Bacille Calmette-Guerin vaccine (BCG) who developed either a cutaneous leishmaniasis (CL) lesion due to exposure to infected sandfly bite(s) or did not develop a lesion during the course of the trial were studied and compared with those of non-vaccinated controls. Blood samples were also assayed from different groups including volunteers with history of CL and volunteers with previous positive or negative leishmanin skin test (LST) without a history of CL. The vaccinated volunteers had received a single dose of either ALM mixed with a low dose of BCG or the same dose of BCG alone. The LST and in vitro proliferative response (stimulation index, SI), interferon gamma (IFN-gamma) production and, in a few cases, interleukin (IL)-4 production of peripheral blood mononuclear cells to soluble Leishmania antigens were measured. The results indicated that volunteers who developed CL in the vaccine arm showed a slightly higher SI than cases who received BCG alone. Volunteers with history of CL and volunteers with positive LST demonstrated the strongest proliferation indices and IFN-gamma production. The data suggest that a single dose of ALM + BCG induces a weak Th1 response in vaccinated volunteers that is far lower than that in volunteers with prior subclinical infection or volunteers with history of CL, who are presumed to be immune.     

Evaluation of meglumine antimoniate effects on liver, kidney and pancreas function tests in patients with cutaneous leishmaniasis

Cutaneous leishmaniasis has been recognized as a major public health problem in several countries. Pentavalent antimonies, meglumine antimoniate and sodium stibogluconate, have been considered as standard treatment for leishmaniasis. Side effects have been reported to be increased hepatic enzyme levels and electrocardiographic abnormalities. We performed this study to evaluate the influence of meglumine antimoniate on some liver, kidney, and pancreas function tests.Eighty patients fulfilled the study criteria. Forty-one (51.3%) patients were female and the mean age of the patients was 30.4 +/- 15.7 years. Blood samples were taken to evaluate liver, kidney, and pancreas function tests before and after treatment with intramuscular injections of MA at a dose of 20 mg Sb(+5)/kg/day for 15 days.Mean serum levels of blood urea nitrogen, creatinine, sodium, total and direct bilirubin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase significantly increased after treatment, although most of them were within normal ranges. There were no significant differences in serum levels of potassium, amylase, lipase, and gamma-glutamyl transpeptidase before and after treatment.In conclusion it can be stated that one course of treatment with 20 mg Sb(+5)/kg/day MA for 15 days does not significantly alter the liver, kidney and pancreas function tests in patients with cutaneous Leishmaniasis.     

First generation leishmaniasis vaccines: a review of field efficacy trials

First generation candidate vaccines against leishmaniasis, prepared using inactivated whole parasites as their main ingredient, were considered as promising because of their relative ease of production and low cost. These vaccines have been the subject of many investigations over several decades and are the only leishmaniasis vaccine candidates which have undergone phase 3 clinical trial evaluation. Although the studies demonstrated the safety of the vaccines and several studies showed reasonable immunogenicity and some indication of protection, an efficacious prophylactic vaccine is yet to be identified. Despite this overall failure, these trials contributed significantly to increasing knowledge on human leishmaniasis immunology. To provide a collective view, this review discusses the methods and findings of field efficacy trials of first generation leishmaniasis vaccine clinical trials conducted in the Old and New Worlds.     

Plasma sCD26 and sCD30 levels in cutaneous leishmaniasis

CD26 and CD30 are surface molecules expressed on activated Th1 and Th2 cells, respectively. It is, therefore assumed that plasma levels of CD26 and CD30 (sCD26 and sCD30) correlate with Th1 and Th2 response, respectively. In this study, plasma levels of sCD26 and sCD30 in patients with non-healing form of cutaneous leishmaniasis (CL) were measured and compared with the levels of sCD26 and sCD30 in patients with healing form of CL and healthy control volunteers. The results indicate that the plasma levels of sCD26 and sCD30 are significantly (p < 0.05) higher in patients with non-healing form of CL than patients with healing form of CL or healthy control. No significant difference is seen in the levels of sCD26 and sCD30 in patients with healing form of CL in comparison with healthy control group. It is concluded that sCD30 might be used as an indicator of a Th2 response in patients with non-healing form of CL.