Iranian Journal of Immunology
Year:2008 | Volume:5 | Issue:4|Papers Count:7

RhD antigen is the most immunogenic and clinically significant antigen of red blood cells after ABO system. It has historically been associated with hemolytic disease of the newborn (HDN) which is now routinely prevented by the administration of polyclonal anti-D immunoglobulin. This management of HDN has proven to be one of the most successful cases of prophylactic treatment based on antibody mediated immune sup-pression (AMIS). Despite the increasing efficiency of treatment, the mechanism of ac-tion of anti-D is not completely defined. There is a widespread interest in obtaining a reliable therapeutic monoclonal anti-D, due to difficulty of maintaining a pool of high titer volunteer donors for plasma collection and also increasing demand for antenatal prophylaxis and safety issues with plasma derived products. Candidate monoclonal anti-D preparations should demonstrate appropriate functionality in both in vitro and in vivo assays comparable to polyclonal anti-D immunoglobulin. These criteria are reviewed in addition to the factors regulating development of D specific immune response in D negative individuals and its suppression in HDN prophylaxis.

Background: Despite advances in the medical care of renal transplant recipients which have led to an improvement in allograft survival, renal allograft rejection is still a major ob-stacle to successful organ transplantation. Understanding the mechanisms contributing to allograft rejection will be of great importance for the development of efficient antirejection strategies.Objective: The aim of current investigation was to study the impact of polymor-phisms of CCR5D32, CCR5- 59029 A/G and CCR2-V64I on renal allograft survival.Methods: Using PCR and PCR-RFLP methods in 84 renal transplant recipients, the influ-ence of CCR5D32, CCR5- 59029 A/G and CCR2-V64I polymorphisms on renal allograft survival in two rejector and non-rejector groups were examined. Rejector group was de-fined as having rejection before 1 year and non-rejector group had stable graft function at least for 5 years.Results: Significant reductions were found in the risk of renal transplant rejection in recipients possessing the CCR2-64I (A) allele (p=0.03) or 59029-A allele (p=0.03) compared to non-rejector group. There were no significant differences in the fre-quency of CCR5D32 polymorphism in rejector group compared to non-rejector group (p>0.05).Conclusion: It was possible to conclude that the chemokine receptors CCR2-V64I (A) and CCR5- 59029 A alleles may influence renal allograft survival.

Background: HLA-G gene contains 15 alleles including a null allele, HLA-G*0105N. Previous studies have shown that HLA-G*0105N does not encode the complete HLA-G1 or HLA-G5 isoforms but encodes a functional HLA-G protein with the ability to in-hibit NK cell cytolysis. Thus, although the biological functions of HLA-G1 and HLA-G5 proteins are abrogated, other isoforms such as HLA-G2 can replace their roles. Stud-ies on the null allele of HLA-G gene could be useful in understanding the genetic vari-ants of HLA-G alleles in ethnic groups.Objective: The goal of this research was to de-termine the frequency of HLA-G*0105N null allele in Iranian healthy subjects.Methods: The frequency of HLA-G*0105N null allele was evaluated in Iranian healthy sub-jects by PCR-RFLP method. Genomic DNA was isolated from the whole blood of 100 randomly selected, healthy, unrelated Iranian individuals using salting-out technique followed by PCR amplification of the exon 3 of HLA-G gene. PCR products were di-gested with PpUM-1 and the resulted fragments were analyzed using gel electrophore-sis.Results: In this study the restriction enzyme digestion confirmed homozygous HLA-G*0105N null allele for 9% of the population. Furthermore obtained results indi-cated that the total frequency of HLA-G*0105N null allele was 20% in the studied population of Iran.Conclusion: The final data analysis showed that the total frequency of this allele in Iranian people was higher than other ethnic groups that have been stud-ied so far.

Background: The risk of developing tuberculosis is high among chronic hemodialysis patients. The tuberculin skin test (TST) has been in use for diagnosing latent TB, but few data are available on TST in hemodialysis patients.Objective: This study was done to identify the TST reactivity and frequency of booster effect in serial TST among hemodialysis patients.Methods: A total of 100 patients in three hemodialysis centers were prospectively tested. Patients with less than 10mm indurations were given addi-tional TST one and four weeks later to determine the frequency of booster effect.Results: The cumulative prevalence of a positive TST was 7 % for the first test and 16 % for the third test. There was a weak, but significant correlation between TST positiv-ity, serum albumin level, urea reduction ratio and KT/V (p<0.05). There was no influ-ence of age, gender, hemodialysis duration and primary renal disease.Conclusion: This study showed that the TST reactivity and booster effect among our hemodialysis pa-tients in Iran are lower than in other societies. Inadequate hemodialysis and poor nutri-tion may contribute to the lower tuberculin skin test reactivity in our hemodialysis pa-tients.

Background: Early Childhood Caries (ECC) is one of the most common chronic childhood diseases. In spite of the global decrease in dental caries in the past decades, ECC has become a significant problem in many developing countries and also in a few industrialized nations. Saliva as a host factor can play an important role in the process of dental caries.Objective: The aim of this study was to compare sIgA and IgG as saliva components between ECC and caries-free groups.Methods: In this cross-sectional study, samples of unstipulated saliva of 90 children (45 in ECC group & 45 in caries-free group) were taken with Scully method. Then the concentration levels of sIgA and IgG were measured with Enzyme Linked Immunosorbent Assay and Single Radial Immunodiffusion methods.Results: Mean concentration levels of salivary sIgA and IgG were significantly higher among children with ECC (p<0.05). There was also a weak inverse correlation between sIgA level and DMFT index in ECC group but it was not statistically significant (p=0.056).Conclusion: The high concentration of salivary immunoglobulin in children with ECC may be associated with an increased antigenic load, leading to high production of antibodies.

Cogan's syndrome (CS) is an immune-mediated disease characterized by ocular in-flammation and audiovestibular dysfunction with or without vasculitis or other systemic manifestations (1). Audiovestibular disease that is difficult to treat can lead to the loss of hearing (2). By a timely recognition and initiation of glucocorticoid therapy at the onset of the disease, poor outcomes, especially complete hearing loss, could sometimes be prevented (2). Certain patients may require long-term corticosteroid therapy because of recurrent hearing loss during attempts to taper the prednisone dose (3). We report Cogan’s syndrome in a 14 year-old-girl with marked deterioration of hearing power fol-lowing tapering of corticosteroid therapy.

Here, we will discuss the importance of the sub cellular localization of proteins (intracellular vs. extracellular) for their antigenicity.To this end, we will discuss the aberrations in protein trafficking and transport-as well as cellular damage, with regard to cell death and necrosis-that can lead to mix-ing of compartments that normally are separated in a healthy organism. Thus, we introduce a new hypothesis in biology, wherein the localization of a protein plays a causal role in its antigenicity. A change in the intracellular or extracellular localization can cause an immune reaction, which, if protein transport dysfunction or cell death is continually present over a longer time-period, it will lead to the development of an autoimmune disease.According to our hypothesis, no defect is necessary within the immune system when an autoimmune disease appears. Aspects of the pathogenetic principle presented here have already been described.