Reference ranges of lymphocyte subsets in healthy Qatari adults.

AIM: Determine reference ranges of lymphocyte subsets in healthy Qatari adults. PATIENTS & METHODS: Blood samples (n = 150) were investigated using four colors flow cytometery. RESULTS: The mean percentage and absolute values of the lymphocyte subsets were: CD3: 73.6 ± 6.1%; 2,072 ± 644 cells/µl; CD4: 41.1 ± 7.9%; 1,167 ± 396 cells/µl; CD8: 33.8 ± 7.1%; 967 ± 364 cells/µl; B cells (CD19(+)): 11.3 ± 3.9%; 318 ± 144 cells/µl and natural killer (NK) cells (CD16/56(+)): 16.5 ± 6.3%, 440 ± 401 cells/µl, respectively. The CD4/CD8 ratio was 1.3 ± 0.5. The ratio, CD3(+) and CD4(+) percentage and CD4(+) cell counts were significantly higher in females; CD8(+) and NK cell count and CD8(+) percentage were significantly higher in males. The impact of age was less certain. CONCLUSION: The reference values of lymphocyte subsets appear to be specific to this population, demonstrating the importance of establishing local reference ranges.

Diagnostic value of pleural fluid interferon-gamma and adenosine deaminase in patients with pleural tuberculosis in Qatar.

OBJECTIVE: To investigate the diagnostic utility of interferon-gamma (IFN-γ) and adenosine deaminase (ADA) in tuberculous pleural effusions by determining the best cutoff levels of these two markers for pleural tuberculosis, in the context of the local epidemiological settings in Qatar. METHODS: We prospectively studied IFN-γ and ADA levels in the pleural fluid of patients presenting to Hamad General Hospital between June 1, 2009 and May 31, 2010. RESULTS: We studied 103 patients with pleural effusions, 72 (69.9%) with pleural tuberculosis, and 31 (30.1%) with nontuberculous etiologies. The mean IFN-γ concentration for the group with tuberculous effusions was significantly higher than that in the group with nontuberculous effusions (1.98 ± 81 vs 0.26 ± 10 pg/mL [P < 0.0001]). The mean ADA activity for the tuberculous effusions group was significantly higher than that in group with nontuberculous effusions (41.30 ± 20.09 vs 14.93 ± 14.87 U/L [P < 0.0001]). By analysis of receiver operating characteristic (ROC) curves, the best cutoff values for IFN-γ and ADA were 0.5 pg/mL and 16.65 U/L, respectively. The results for IFN-γ vs ADA were: for sensitivity, 100% vs 86%, respectively; for specificity, 100% vs 74%, respectively; for positive predictive value, 100% vs 88.5%, respectively; and for negative predictive value, 100% vs 69.7%, respectively. CONCLUSION: IFN-γ and ADA could be used as valuable parameters for the differentiation of tuberculous from nontuberculous effusion, and IFN-γ was more sensitive and specific for tuberculous effusion than ADA.

Evidence of occult hepatitis B virus infection among Omani blood donors: a preliminary study.

OBJECTIVES: The aim of this study was to determine the prevalence of hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (anti-HBc) and hepatitis B virus (HBV) DNA among a selected group of Omani blood donors. MATERIALS AND METHODS: Two hundred HBsAg-negative donors were screened for anti-HBc. Those found to be positive were investigated for HBV DNA by polymerase chain reaction. HBsAg was retested on these sera following an immune complex dissociation technique. RESULTS: HBsAg was present in 2.8% of the donors. Forty-one out of 200 (20.5%) HBsAg-negative donors were positive for anti-HBc. Eleven were positive for HBsAg after dissociation, whereas 8 gave readings just over the cutoff. HBV DNA was not detected in this group. CONCLUSION: Findings indicate that testing donors for HBsAg alone is not sufficient to eliminate HBV from the blood supply in Oman.

Correlation between Serum Leptin Levels, Body Mass Index and Obesity in Omanis.

OBJECTIVE: To ascertain the relationship between serum leptin levels and related variables (weight, Body Mass Index (BMI) and fat percentage) in a group of Omani obese and non-obese healthy subjects. METHODS: Leptin levels were assessed in serum samples from 35 obese Omanis and 20 non-obese healthy subjects. RESULTS: There was a significant difference (p< 0.001) in serum leptin between the obese group (34.78 + 13.96 ng/ml) and the control non-obese subjects (10.6 ± 4.2 ng/ml). Leptin levels were higher in females compared to males. There was a significantly positive correlation between leptin levels in obese subjects with weight (p=0.002), body fat percentage (p=0.0001) and BMI (p=0.001). CONCLUSIONS: We concluded that serum leptin levels are higher in the Omani obese group and correlate positively with body fatness and obesity.

Inhibition effect of honey on the adherence of Salmonella to intestinal epithelial cells in vitro.

The aim of the study was to evaluate the antimicrobial effect and the ability of honey to prevent Salmonella interitidis adhering to intestinal epithelial cells in vitro. Antimicrobial activity was demonstrated. Bacterial adherence was assayed using S. interitidis cells that had been incubated first with honey and then with the intestinal epithelial cells. Results showed that honey at dilutions of up to 1:8 reduced bacterial adherence from 25.6+/-6.5 (control) to 6.7+/-3.3 bacteria per epithelial cell (P<0.001).

Determination of the levels of anti-thyroid-stimulating hormone receptor antibody with thyroid peroxidase antibody in Omani patients with Graves' disease.

OBJECTIVE: To determine the levels of anti-thyroid-stimulating hormone receptor antibody (TRAb) and thyroid peroxidase antibodies (TPO) in Omani patients with Graves' disease (GD). SUBJECTS AND METHODS: ELISA was used to measure the levels of TRAb and TPO in sera of 111 patients with GD, 40 patients with systemic lupus erythematosus (SLE) and 50 healthy normal subjects. Seventy-eight GD patients received iodine-131 treatment while 33 newly diagnosed patients did not receive any treatment. RESULTS: The levels of TRAb in the patients with GD, SLE and normal subjects were 7.24 9+/-0.623, 1.04+/-0.179 and 0.539+/-0.070 units/liter, respectively. Elevated levels of TRAb were found in 75, 5 and 2% of patients with GD, SLE and normal subjects, respectively. For anti-TPO antibodies, the levels were 713.331+/-97.905, 85.575+/-34.936 and 22.96+/-4.544 lU/ml, for patients with GD, SLE and normal subjects, respectively. The elevated level of anti-TPO antibodies were found in 72, 15 and 6% of patients with GD, SLE and normal subjects. Statistically significant differences in positive levels of TRAb and anti-TPO antibodies were found in patients with GD as compared to SLE and normal subjects (p<0.001). The treated GD patients had lower levels of TRAb than untreated, but no difference was detected in the levels of anti-TPO antibodies between the treated and not treated. CONCLUSION: High levels of TRAb and TPO were detected in Omani patients with GD. TRAb may be helpful in the diagnosis and monitoring the efficacy of iodine-131 treatment in GD patients.

Cytokine profile of sickle cell disease in Oman.

The aim of our study was to assess the cytokine profile of sickle cell disease (SCD) patients in steady state and in vaso-occlusive crisis (VOC). VOC has a complex nature, involving interactions between sickle red blood cells (RBC), the endothelium, and leucocytes. Endothelial damage due to recurrent adhesion of sickle RBCs may disrupt endothelial function, leading to altered cytokine release. It is therefore pertinent to study the cytokine profile of SCD patients in steady state and in crisis prior to exploring its contribution to vaso-occlusive manifestations, since it is believed that an altered balance of proinflammatory and anti-inflammatory cytokines plays an important role in painful crisis. Cytokines including IL-1beta, IL-2, IL-4, IL-6, IL-8, TNF-alpha, and IFN-gamma were measured by commercially available ELISA kits in SCD patients (n = 60); in steady state (n = 26) and in painful crisis (n = 34) and compared with nonanemic age- and sex-matched normal Omani controls (n = 20). SCD patients in crisis showed elevated levels of TNF-alpha (P < 0.092) and IL-6 (P < 0.024) when compared with steady state. It was also observed that SCD patients in steady state showed a significant elevation in IL-1beta (P < 0.04), IL-6 (P < 0.0001), and IFN-gamma (P < 0.02) as compared to normal subjects. It is thus evident that both type I and type II cytokines are significantly altered in SCD patients. In steady state, type II proinflammatory cytokines are elevated, whereas in crisis, an additional augmentation of type I cytokines occurs, with persistent elevation of type II cytokines, emphasizing the role of perturbed endothelium and activated monocytes in the pathophysiology of vaso-occlusion in sickle cell crisis.