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.

Levels of cytokines and thyroid autoantibodies in Omani patients with Graves' disease

An altered balance of pro- and anti-inflammatory cytokines is thought to play an important role in the pathogenesis of autoimmune thyroiditis. The aim of the present study is to assess the cytokine and autoantibody profiles in Omani patients with Graves' disease (GD). Cytokines and autoantibodies including interleukin (IL)-2, IL-4, tumour necrosis factor (TNF)alpha, interferon (IFN)gamma, thyroid stimulating hormone receptor antibody (TRA) and thyroid peroxidase antibody (TPO) are measured in GD patients (n=59) before treatment (n=23) and after treatment (n=36) with 131I-labelled iodine, and compared with normal controls (n=20). Patients with GD showed comparable serum levels of IL-2 but significantly higher levels of IL-4, TNFalpha, IFNgamma, TRA and TPO, compared with the normal controls. There was also a significant increase in serum levels of IL-4 and TNFalpha, and a decrease in TRA in the treated group, compared to the untreated group. IL-4, TNFalpha, IFNgamma, TRA and TPO showed a high prevalence in Omani patients with GD. Thus, cytokines and autoantibodies may prove useful in the diagnosis of GD and in assessing prognosis.

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.

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.

Anti-Nuclear Antibody (ANA) Negative Systemic Lupus Erythromatosus

We report the diagnosis of Systemic Lupus Erythematosus (SLE) in an Omani lady with consistently negative antinuclear antibody (ANA) results and an anti double stranded DNA (dsDNA) titre of 1:640. The presence of a negative ANA with a high titre of dsDNA is very unusual in SLE

Prevalence of autoantibodies in patients with hepatitis C virus infection in Oman

BACKGROUND

HCV genotype patterns and HLA types in the Omani population may be unique.

SUBJECTS AND METHODS

Tests for 12 different autoantibodies were carried out on 50 HCV-infected patients and on 27 HCV-seronegative controls. An immunoassay for the detection of anti-HCV antibodies was performed on patient and control sera. HCV PCR was carried out on those sera which were positive for HCV antibodies.

RESULTS

All patients sera were positive for HCV antibodies and all control sera were negative. Sixty-six percent of patients were positive for at least one autoantibody. In contrast, only 33% of the controls showed positivity for one or more autoantibodies.

CONCLUSION

This study found a significant difference in the prevalence of autoantibodies between patients and controls, and between organ- and non-organ specific autoantibodies among the patients. A comparison with autoantibody patterns reported for HCV-infected patients in other parts of the world suggest that patterns in HCV-infected individuals in the Omani population are unique.