ABSTRACT
Background: H. pylori-associated gastritis in patients from the high-altitude area of Ladakh showed severe gastritis, mucosal nodularity, atrophy, and cancer in comparison to those from North India. This study served to analyze if differences in the H. pylori virulence genotypes decide the extent of gastric mucosal inflammation. Methods: Fifty gastric biopsies each from patients with H. pylori-associated gastritis from Ladakh and a tertiary care center in North India were included. The presence of H. pylori strain was confirmed with Warthin starry stain and polymerase chain amplification of the H. pylori-specific 16S rRNA. The cagA, vacA s1, s2, and m1, m2 alleles, and dupA virulence genotypes were studied in all archival samples, followed by their histological correlations. Results: cagA (P 0.009) and vacAs1 m1 (P 0.009) genes were distinctly more in H. pylori strains colonizing the biopsies of North Indian patients. In contrast, the cagA -ve vacAs2 m2 strains were significantly more in H. pylori strain colonizing the biopsies from Ladakhi patients. dupA genotype was almost similarly present in strains from both regions. Among these, only cagA and dupA virulence genes were associated with severe mucosal neutrophilic activity and deep infiltration of H. pylori strains in North Indian patients. Conclusions: Differences in virulence genotypes of H. pylori in gastric biopsies from North Indian and Ladakhi patients were found not significant in deciding the severity of H. pylori-associated gastritis.
ABSTRACT
Background: It is hypothesized that the duodenal mucosal damage in patients with celiac disease (CeD) is caused by the mucosa-infiltrating lymphoid cells. This study aimed to analyze the immune effective and regulatory T (Treg) cells in duodenal biopsies from treatment-naive adult patients with CeD having different histological grades and controls. Patients and Methods: Dual-color immunohistochemical staining was done in a total of 234 duodenal biopsies, including 132 controls and 102 adult patients with CeD using CD20, CD3:CD4, CD3:CD8, CD4:FoxP3, CD8:FoxP3, and TCR??:TCR?? antibodies. The density of these lymphoid cells in lamina propria and mucosal epithelium was compared between controls and CeD, with different modified Marsh grades. Results: Densities of CD4+ T cells in lamina propria and CD8+?? intraepithelial lymphocytes (IELs) were significantly more in biopsies from patients with CeD, than in controls. An increasing linear pattern of IELs, CD3+ T cells, and CD20+ B cells was observed with increasing grades of villous abnormalities. Although CD8+ FoxP3+ Treg cells were significantly more in biopsies from patients with CeD, there was no significant difference in CD4+ FoxP3+ Treg cell infiltrate between both the groups. Conclusion: Our finding in this observational study generates interest to study the local intestinal mucosal immunity in CeD in detail. A study to prove the failure of CD4+ FoxP3+ Treg cell recruitment in CeD and its direct functional impact may yield valuable information regarding loss of mucosal tolerance.
ABSTRACT
Purpose: Cyclospora cayetanensis is an intestinal coccidian protozoan that has emerged as an important cause of both epidemic and endemic protracted diarrhea worldwide. Though humans appear to be the only natural hosts; the role of animals as natural reservoir is uncertain but of increasing concern. The present study aimed to study the prevalence of coccidian in different groups such as immunocompromised, clinically apparent immunocompetent and healthy individuals. Also, the study isolates were assessed for heterogeneity among the sequences. Materials and Methods: Stool samples from different groups of patients were collected. The parasite was detected in stool by different diagnostic tools such as light microscopy and nested PCR‑restriction fragment length polymorphism using 18S ribosomal RNA as the target gene. Results: The prevalence of C. cayetanensis was 2.4% (19/800) in the present study. The PCR assay amplified Cyclospora cayetanensis DNA in only 89% (17/19) isolates. Further, sequencing revealed no significant difference among the study isolates and the non‑primates. Phylogenetic analysis of the study isolates however, formed two clusters. While one cluster showed close evolutionary association with the C. cayetanensis strains, the other cluster showed evolutionary association with the two non‑primate species. Conclusion: The methods described here for detection of C. cayetanensis oocysts are simple, efficient, specific, and sensitive and therefore can be effectively applied for laboratory diagnosis and environmental assessment of fresh produce and water sources. Clinicians should include Cyclospora infection in the differential diagnosis of prolonged or relapsing diarrheal illness even in clinically apparent immunocompetent individuals.