Human Leukocyte Antigen B27 (HLA-B27) in the General Population in the Kingdom of Saudi Arabia.

BACKGROUND: Determining the prevalence of the human leukocyte antigen B27 (HLA-B27) in the general population in the Kingdom of Saudi Arabia. METHODS: This cross-sectional study was performed at King Abdulaziz University in the period May 23, 2019 - August 31, 2019 and included four hundred Saudi healthy blood donor subjects (200 male [50%]). We used blood samples in ethylenediaminetetraacetic acid (EDTA) tubes. The HLA-B27 alleles were detected by the Single Specific Primer-Polymerase Chain Reaction (SSP-PCR) using the HLA-B27 Screen Real Time kit from BioDiagene S.R.L (Palermo, Italy). Data analysis was achieved by the statistical package for social science (IBM SPSS Inc., version 20). RESULTS: Ten (2.5%) were positive for HLA-B27 (6 female [60.00%]). HLA-B27 positivity in blood groups was 3% in O and B, 1.7% in A, nil in AB but almost equal in Rh+ve (2.5 %) and Rh-ve (2.4 %) blood groups, with no significant difference neither between male and female (p = 0.52), nor between blood groups (p = 0.77). CONCLUSIONS: The prevalence of 2.5% for HLA-B27 in the general Saudi population was similar to that of Omair et al. using samples of Saudi cord blood [14]. The positivity in females was 1.5 times higher than in males. No correlation was seen between HLA-B27 and gender and blood groups.

Small intestinal bacterial overgrowth among patients with celiac disease unresponsive to a gluten free diet.

BACKGROUND/AIMS: Little is known about the relationship between small intestinal bacterial overgrowth (SIBO) and celiac disease (CeD) in patients who are unresponsive to a gluten-free diet (GFD). This study aimed to determine the SIBO prevalence in patients with CeD who are unresponsive to a GFD. MATERIALS AND METHODS: We conducted a case-control study from July 2012 to September 2014. We included 32 patients with CeD who were unresponsive to a GFD and 52 healthy age- and sex-matched controls. Demographic, clinical, and laboratory data were obtained from patients' medical records. Antitissue transglutaminase antibody determined by enzyme-linked immunosorbent assay was recorded, and lactulose hydrogen breath test (LHBT) was used to detect SIBO in all participants. Microbiological analysis, including jejunal aspirates obtained using upper endoscopy, was performed for only 20 patients with CeD. RESULTS: A total of 10 (31%) of 32 patients with CeD and 4 (7.7%) of 52 controls tested positive for LHBT, with a statistically significant difference (p=0.007). Of 20 cultures, 3 (15%) were positive with no statistically significant correlation between the cultures and LHBT (p=0.05). In a subgroup analysis of children who were 18 years old or younger, 7/24 (29.2%) patients with CeD had a positive LHBT compared with 3/32 (9.4%) controls, but this difference was not statistically significant (p=0.08). CONCLUSION: The prevalence of SIBO was 31% in unresponsive patients with CeD according to LHBT and 15% in the quantitative culture of the jejunal aspirate, which is comparable with the published Western literature.

Celiac disease among at-risk individuals in Saudi Arabia.

OBJECTIVES: To perform a meta-analysis for celiac diseases (CD) among at-risk populations in Kingdom of Saudi Arabia (KSA), as well as a comparison with our previously reported meta-analysis in the normal population. METHODS: In March 2018, at King Abdulaziz University,  Jeddah, KSA we commenced a retrospective comprehensive database and journal search for CD among at-risk populations in SA. Data from each of the relevant articles were analyzed using the  Statistical Package for Social Science Version 20 (Armonk, NY: IBM Corp.). and the comprehensive meta-analysis program (CMA). The collected data were part of a retrospective literature review and analysis. Thus, a written ethical approval was not obtained before commencing the study. Results: Sixteen articles were found covering type-1 diabetes mellitus (DM), short stature (SS), and down syndrome (DS). Ages 1-50 years . The prevalence of seropositive-CD was 15.6% with high heterogeneity (I2=80.353), while prevalence of biopsy-proven CD was 10.6% with high heterogeneity (I2=73.359). Another article reported the CD prevalence in the at-risk population as 18.4% for the seroprevalence and  6.9% for the biopsy-proven CD. Anti-transglutaminase (anti-tTG) was used in 12 studies; in the remaining 4 studies (EMA in 2, ARA with AGA in one and no details given in one study). Conclusion: Both the prevalence of biopsy-proven CD (10.6%) and seroprevalence (15.6%) were higher than those we previously reported in the normal population (1.4% and 2.7%). The female-to-male ratio (1.9/1) of CD patients was the same in normal and at-risk populations in SA. Meta-analysis for prevalence of CD in DM, SS, and DS separately in SA is recommended.

Hepatitis C: an Overview of Various Laboratory Assays with their Mode of Diagnostic Cooperation.

BACKGROUND: This review describes in chronological order the different assays for hepatitis C virus (HCV) antibodies, for the core antigen and for the HCV-RNA. METHODS: By ascending chronological order, the enzyme-linked immunosorbent assay (ELISA), rapid diagnostic tests (RDTs), HCV-Ab IgG avidity index (HCV AI), and Cy3-labeled microarray assay have been described for HCV antibodies in addition to ELISA for the total HCV core antigen (Ag). RESULTS: The recombinant immunoblot assay (RIBA) is a confirmatory test for HCV-Ab in blood, which is no longer needed due to the use of the sensitive third and fourth generation ELISA in addition to HCV-RNA detection by the Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). ELISA and RIBA measure current and prior exposure to HCV infection, but cannot discriminate between the two. RT-PCR is performed after ELISA for the diagnosis of HCV infection whether acute, chronic, false positive or false negative ELISA. CONCLUSIONS: The cooperation between ELISA and RT-PCR in the diagnosis of HCV infection has been tabulated and discussed. HCV genotyping and subtyping testing is essential in pre-treatment evaluation of the patients for setting valuable treatment strategies and in understanding the epidemiology of the virus.

Anti-mutated citrullinated vimentin antibody and rheumatoid factor (prevalence and association) in rheumatoid arthritis patients; Saudi and non-Saudi.

UNLABELLED: background: The aims of this study were to assess the prevalence of anti-mutated citrullinated vimentin (MCV) antibodies and rheumatoid factor (RF) and to evaluate their association in rheumatoid arthritis patients, both Saudi and non-Saudi. METHODS: Retrospectively, we studied 280 rheumatoid arthritis patients, at King Abdulaziz University Hospital. The antibodies were measured by enzyme linked immunosorbent assay and rheumatoid factor by nephelometry. RESULTS: The 280 patients included 196 Saudis and 84 non-Saudis, 88% females and 12% males, and the mean age was 45.3 years (SD = 14.3). Prevalence of rheumatoid factor was 141/280 (50%) divided as 93/196 (47.5%) Saudis and 48/84 (57%) non-Saudis, with no significant differences (p > 0.05). Prevalence of mutated citrullinated vimentin antibodies was 165/280 (58.2%) divided as 121/196 (61.7%) Saudis and 44/84 (52.4%) non-Saudis, with no significant differences (p > 0.05). Among RF -ve patients, considerable numbers were anti-MCV +ve, and vice versa. Also, among the anti-MCV -ve patients, considerable numbers were RF +ve, and vice versa. In all cohorts and in Saudi and non Saudi patients, anti-MCV positivity was significantly associated with RF positivity (odds ratio (OR) 3.15; 95% CI 1.9, 5.19/p = 0.000); ESR and CRP were high with significant correlation (p < 0.005) with each other, with RF positivity but not with anti-MC positivity. Anti-MC positivity showed no significant correlation with age and gender. CONCLUSIONS: In this cohort of patients, anti-MCV antibodies are a useful diagnostic tool for RA, but its combination with RF is essential. Both markers are significantly associated. Larger scale studies are recommended. Correlation of anti-MCV with treatment and with disease activity still has to be published.

Pattern of drugs use and association with anti-mutated citrullinated vimentin antibody in rheumatoid arthritis.

OBJECTIVES: To demonstrate the pattern of disease-modifying antirheumatic drugs (DMARDs) use in Saudi and non-Saudi rheumatoid arthritis (RA) patients, and to evaluate the association of DMARDs use with anti-mutated citrullinated vimentin (anti-MCV) positivity and other factors. METHODS: Retrospectively, for a period of 7 years (2007-2014), we studied 205 RA patients, at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. All patients used DMARDs. Pattern of use for all 6 DMARDs was almost the same among Saudis and non-Saudis with no significant difference (p>0.05) for each DMARD; MTX was the most commonly used DMARD (71-76%). RESULTS: There was no association between anti-MCV positivity and different DMARDs use. Methotrexate was used 76 times as combination, scoring the highest in this respect. There was a significant correlation (p<0.05) between Plaquenil with Methotrexate and with Sulfasalazine; Leflunomide with anti-TNF and with Prednisolone; age with Methotrexate and with Plaquenil; anti-MCV positivity with Prednisolone. Saudi/non-Saudi status showed no correlation with all factors or drugs. There was no significant association between DMARDs and comorbidity. CONCLUSION: Similar to worldwide results, MTX was the most commonly used DMARD; with the addition of anti-TNF to increase the effect, and folic acid to minimize the side effects. In this cohort, the pattern of use for all DMARDs was similar among Saudis and non-Saudis; treatment depended neither on anti-MCV positivity nor on the presence of comorbid conditions. A study of the association of DMARDs with disease activity is recommended.

An overview of various labeled assays used in medical laboratory diagnosis. Immune and non-immune assays.

In this review, some light is thrown on various labeled immunoassays that depend on antigen-antibody (Ag-Ab) reactions, including immunofluorescence, radioimmunoassay, and enzyme immunoassay (EIA or ELISA). Their definitions, principles, and applications are described, then they are discussed chronologically to show their stepwise development that led finally to full automation. Enzyme labeled immunoblot assays (Western blot, blot spot, and recombinant immunoblot assay), and luminescence (bioluminescence and chemiluminescence) are also discussed chronologically. Labeled assays, that do not involve Ag-Ab reaction but rather, utilizing biotin-streptavidin (BS) interaction and probe-target DNA interaction, are described, together with their applications for DNA/RNA detection and genotyping. Finally, included in the discussion were some luminescent labeled techniques that utilize the immune Ag-Ab reaction together with non-immune BS reaction, such as the luminescent oxygen channeling immunoassay, and its commercialized AlphaLISA, both eliminate the washing steps without sacrificing high sensitivity, or wide dynamic range.