Search

Background: The pathological events during diabetes mellitus (DM) and hypertension (HTN) could induce hyper-vascular injuries and coagulopathies in affected patients. Thus, this prospective comparative study aims to assess the prothrombin time (PT), partial thromboplastin time with kaolin (PTTK) and international normalized ratio (INR) as biomarkers of potential coagulopathies in diabetics with hypertension (test group) and those without hypertension (control group) at Specialist Hospital Sokoto, North-western Nigeria. Materials and methods: Whole blood samples were obtained from 74 diabetic patients with hypertensive and 37 diabetic patients without hypertension and analysed for the PT, PTTK and INR values using commercially available kits. The sociodemographic variables of the enrolled participants were collated and statistically analysed against the coagulometric values using suitable tests. Results: Participants between 50-59 years (39.2%) were the most frequently enrolled participants, followed by 40-49 years (29.73%). Females comprised 56.8% while males were 43.2% of the participants. The PT, PTTK and INR were not statistically significant between diabetes with hypertension and diabetes without hypertension which were (9.22 ± 1.78, 30.27 ± 18.18 and 0.70 ± 0.15) and (9.51 ± 1.85, 36.57 ± 17.17 and 0.72 ± 0.14) respectively (p = 0.532, p = 0.061 and p= 0.575). The age group of the subjects showed a significant increase in PTTK when compared with PT and INR (p = 0.392, p = 0.002 and p = 0.467). There were increases but statistically non-significant in PTTK when compared with PT and INR based on occupation (p =0.833, p = 0.000 and p = 0.779) respectively. Conclusion: Findings from this study showed no significant variation in PT, PTTK and INR of diabetics and diabetics with hypertension. However, future studies could be done to focus on platelet factors and other highly sensitive biomarkers of the coagulation system of these populations. Nevertheless, monitoring the PTTK in older diabetic patients with diabetes mellitus is important to prevent hypercoagulation.

Despite the efforts to encourage the intake of nutritional supplements during antenatal periods, there are still many cases of anemia and protein-energy malnutrition during pregnancy. Hence, this study determined the incidence of anemia, protein-energy malnutrition, and associated risk factors among pregnant women in Abuja, Nigeria.This hospital-based, case-control study involved randomly selected 176 pregnant and non-pregnant women attending the University of Abuja Teaching Hospital (UATH), Gwagwalada, Nigeria. Hemoglobin and hematocrit measurements were used to determine anemia incidence, while plasma protein, zinc levels and body mass index (BMI) were used to determine energy index status. Complete blood counts were analyzed using 5 parts-automatic hemo-analyzer, while plasma protein and zinc were analyzed using calorimetric method. Anemia and protein-energy malnutrition were defined using the World Health Organization (WHO) cut-off values.The mean age of participants was 28.75 ± 5.22 years. Out of 176 participants, 7 (4%) were malnourished while 25% of the participants were anemic. Anemia was significantly associated with participants' occupation (p = 0.002), parity (p0.001) and gestational age (p0.001). Most hematological indices, plasma globulin, albumin, protein, and zinc levels were significantly different (p0.001) among non-pregnant and pregnant women of the first, second and third trimesters.The incidence of anemia and malnutrition was high among study participants. There is a need for improved nutritional intervention, increased awareness and strengthening of health systems in the area of maternal health in Nigeria.

Tobacco use is a major risk factor for tuberculosis (TB). Secondhand smoke (SHS) is also a risk factor for TB and to a lesser extent, Mycobacterium tuberculosis infection without disease. We investigated the added risk of M. tuberculosis infection due to SHS exposure in childhood contacts of TB cases in The Gambia. Participants were childhood household contacts aged ≤ 14 years of newly diagnosed pulmonary TB (PTB) cases. The intensity of exposure to the case was categorized according to whether contacts slept in the same room, same house, or a different house as the case. Contacts were tested with an enzyme-linked immunospot interferon gamma release assay. In multivariate regression models, M. tuberculosis infection was associated with increasing exposure to a case (odds ratios [OR]: 3.9, 95% confidence interval [CI]: 2.11–71.4, P < 0.001]) and with male gender (OR: 1.5 [95% CI: 1.12–2.11], P = 0.008). Tobacco use caused a 3-fold increase in the odds of M. tuberculosis infection in children who slept closest to a case who smoked within the same home compared with a nonsmoking case (OR: 8.0 [95% CI: 2.74–23.29] versus 2.4 [95% CI: 1.17–4.92], P < 0.001). SHS exposure as an effect modifier appears to greatly increase the risk of M. tuberculosis infection in children exposed to PTB cases. Smoking cessation campaigns may be important for reducing transmission of M. tuberculosis to children within households.

Background: Low hemoglobin (Hb) and iron deficiency among child bearing females have been linked to decreased immune system function, impaired cognitive functioning and complications in pregnancy. Methods: A total of 106 blood samples from apparently healthy nulliparous female students were assayed for Hb and serum iron concentrations using the cyanmethemoglobin and bathophenanthroline methods, respectively, to evaluate changes that may occur in these parameters at different phases of the reproductive cycle. Results: The mean (SD) Hb values during the ovulatory, menstrual, and follicular phases were 13.27 (1.14) g/dL, 12.05 (1.31) g/dL, and 12.23 (1. 56) g/dL, respectively. The prevalence of anemia (Hb

Background: We compared the performance of tuberculin skin test (TST), Quantiferon-TB Gold in-tube (QFT-GIT), and T-SPOT.TB in diagnosing latent tuberculosis (LTBI) among childhood TB contacts in a TB endemic setting with high BCG coverage. We evaluated the performance of interferon gamma release assays (IGRAs) and TST when combined in an algorithm. Methods: Childhood contacts of newly diagnosed TB patients were tested with TST, QFT-GIT, and T-SPOT. The level of exposure in contacts was categorized according to whether they slept in the same room, same house, or a different house as the index case. For the evaluation of combined test performance, prior estimates for prevalence of latent TB were used in Bayesian models that assumed conditional dependence between tests. Results: A total of 285 children were recruited. Overall, 26.5%, 33.0%, and 33.5% were positive for TST, T-SPOT, or QFT-GIT, respectively. All 3 tests responded to the gradient of sleeping proximity to the index case. Neither TST nor IGRA results were confounded by BCG vaccination. There was moderate agreement ( 0.40 – 0.68) between all 3 tests. Combination of either IGRA with TST increased sensitivity (by 9.3%–9.6%) especially in contacts in the highest exposure category but was associated with loss of specificity (9.9%–11.3%). Conclusion: IGRAs and TST are similar in their diagnostic performance for LTBI. An approximate 10% sensitivity benefit for using the TST and an IGRA in combination is associated with a slightly greater specificity loss. Testing strategies combining an IGRA and TST with an “or” statement may be useful only in situations where there is a high pretest probability of latent infection.

Interferon gamma remains a key effector molecule that is still widely used as the most informative biomarker for screening human immune responses against tuberculosis, particularly in ELISPOT assays. We investigated the participation of CD4(+) and CD8(+) T lymphocytes in the PBMC responses to Mycobacterium tuberculosis (Mtb) specific antigens in 33 TB cases and 49 contacts. Responses to ESAT-6 were higher than CFP-10. There was no significant difference in responses to both Mtb antigens between cases and contacts. PBMCs response to ESAT-6 but not CFP-10 in cases was significantly reduced by depletion of CD4(+) cells whereas CD8(+) cell depletion had no impact. In conclusion, ESAT-6 is a more recognized antigen in this population, and CD4(+) lymphocytes are the main participants in IFN-gamma response by ELISPOT. Thus, a decline of CD4(+) T lymphocytes below a critical level might affect the sensitivity of IFN-gamma release assays for detecting Mtb infection.

Summary Regulatory T lymphocytes (Tregs) that express FOXP3 are involved in the beneficial attenuation of immunopathology, but are also implicated in down-regulation of protective responses to infection. Their role in tuberculosis (TB) is unknown. We classified 1272 healthy TB contacts according to their tuberculin skin test (TST) and interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) results and 128 TB cases, and studied the expression of FOXP3 and interleukin (IL)-10 in blood samples. Compared to the uninfected contact group (TST–, ELISPOT–), we observed higher levels of FOXP3 mRNA in blood from TB patients (

The purified protein derivative (PPD) skin test for Mycobacterium tuberculosis infection lacks specificity. We assessed 2 more specific M. tuberculosis antigens (ESAT-6 and CFP-10) by enzyme-linked immunospot assay (ELISPOT) compared with PPD by ELISPOT and skin test in The Gambia. Of 735 household contacts of 130 sputum smear‐positive tuberculosis cases, 476 (65%) tested positive by PPD ELISPOT, 300 (41%) tested positive by PPD skin test, and 218 (30%) tested positive by ESAT-6/CFP-10 ELISPOT. Only 15 (2%) had positive ESAT6/CFP-10 results and negative PPD results by ELISPOT. With increasing M. tuberculosis exposure, the percentage of subjects who were PPD skin test positive/ESAT-6/CFP-10 ELISPOT negative increased ( ), P ! .001 whereas the percentage of subjects who were PPD skin test negative/PPD ELISPOT positive decreased (P p ). Eighteen (31%) ESAT-6/CFP-10 ELISPOT‐positive subjects in the lowest exposure category had negative .011 PPD skin test results. ESAT-6/CFP-10 ELISPOT probably offers increased specificity in the diagnosis of M. tuberculosis infection in this tropical setting of endemicity, at the cost of some sensitivity.

Objective: To determine the prevalence of transmissible malaria in apparently healthy blood donors in the city of Jos in north-central Nigeria. Methods: We collected blood specimens from individuals who had passed the screening criteria for blood donation. We created thin and thick blood films using the blood film template provided by the World Health Organization (WHO). The films were allowed to air dry; then, we stained them using a 3% Giemsa solution and examined them microscopically. In specimens that tested positive the malaria species was identified. Results: The highest prevalence of malaria was in donors aged between 31 and 40 years (65.1%), whereas the lowest prevalence was in donors aged 20 years or younger (25.0%). Plasmodium falciparum was the predominant species (98.0%); the least prevalent was Plasmodium malariae (2.0%). In male donors the prevalence of malaria parasitemia was 62.0%; the prevalence in female donors was 62.5%. Among paid donors the malaria parasitemia rate was 82.3%, compared with 22.4% in volunteer donors. Donors who reported their occupation as businessperson (individual who engages in commercial trade, mostly outdoors in a market environment) had the highest prevalence, at 94.3%; students had the lowest prevalence, at 31.9%. Conclusion: A high percentage of blood donors in Jos, Nigeria, actually harbor malaria, which is cause for concern and more careful donor screening by healthcare professionals in that region is warranted. * HIV : human immunodeficiency virus HBsAg : hepatitis B surface antigen WHO : World Health Organization

Biomarkers that can be used to evaluate new interventions against latent tuberculosis infection (LTBI) and predict reactivation TB disease are urgently required.To evaluate ESAT-6 and CFP-10 (EC) IFN-γ ELISPOT as a biomarker for treatment efficacy in LTBI.This was a randomized, blinded, and placebo-controlled trial of INH in EC ELISPOT and Mantoux test positive participants.Participants received a 6-month course of 900 mg INH twice weekly or a matching placebo. INH acetylator genotypes were determined and urine tested for INH metabolites to confirm adherence. The proportion of positive responders for CFP-10 and ESAT-6 between treatment arms was compared using mixed effects logistic regression models. A Tweedie (compound Poisson) model was fitted to allow for zero inflation and overdispersion of quantitative response. The proportions of EC ELISPOT-positive subjects reduced over time (P0.001) but did not differ by study arm (P = 0.36). Median spot-forming units for ESAT-6 and CFP-10 also declined significantly with time (P0.001) but did not differ by study arm (P = 0.74 and 0.71, respectively). There was no evidence of an interaction between acetylator status and INH treatment with respect to ELISPOT results over time.In contacts with LTBI, INH therapy plays no role in observed decreases in Mycobacterium tuberculosis antigen-specific T-cell responses over time. IFN-γ ELISPOT is probably not a useful biomarker of treatment efficacy in LTBI. Clinical trial registered with www.clinicaltrials.gov (NCT 00130325).

Background IFN-γ Release Assays (IGRAs) have been licensed for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). Their performance may depend on assay format and may vary across populations and settings. We compared the diagnostic performance of an in-house T -cell and commercial whole blood-based IGRAs for the diagnosis of LTBI and TB disease in The Gambia. Methods Newly diagnosed sputum smear positive cases and their household contacts were recruited. Cases and contacts were bled for IGRA and contacts had a Mantoux skin test. We assessed agreement and discordance between the tests and categorized a contact's level of M. tuberculosis exposure according to where s/he slept relative to a case: the same room, same house or a different house. We assessed the relationship between exposure and test results by multiple logistic regression. Results In 80 newly diagnosed TB cases, the sensitivity of ELISPOT was 78.7% and for QFT-GIT was 64.0% (p = 0.047). Of 194 household contacts 57.1% and 58.8% were positive for ELISPOT and QFT-GIT respectively. The overall agreement between both IGRAs for LTBI in contacts was 71.4% and there was no significant discordance (p = 0.29). There was significant discordance between the IGRAs and TST. Neither IGRA nor TST had evidence of false positive results because of Bacille Calmette Guérin (BCG) vaccination. However, agreement between QFT-GIT and TST as well as discordance between both IGRAs and TST were associated with BCG vaccination. Both IGRAs responded to the M. tuberculosis exposure gradient and were positively associated with increasing TST induration (p = 0.003 for ELISPOT and p = 0.001 for QFT-GIT). Conclusion The ELISPOT test is more sensitive than the QFT-GIT for diagnosing TB disease. The two tests perform similarly in the diagnosis of LTBI in TB contacts. Significant discordance between the two IGRAs and between each and the TST remain largely unexplained.

BACKGROUND: Very little longitudinal information is available regarding the performance of T cell-based tests for Mycobacterium tuberculosis infection. To address this deficiency, we conducted a longitudinal assessment of the enzyme-linked immunosorbent spot test (ELISPOT) test in comparison to the standard tuberculin skin test (TST). METHODS AND FINDINGS: In tuberculosis (TB) contacts we repeated ELISPOT tests 3 mo (n = 341) and 18 mo (n = 210) after recruitment and TSTs at 18 mo (n = 130). We evaluated factors for association with conversion and reversion and investigated suspected cases of TB. Of 207 ELISPOT-negative contacts, 51 (24.6%) had 3-mo ELISPOT conversion, which was associated with a positive recruitment TST (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.0-5.0, p = 0.048) and negatively associated with bacillus Calmette-Guerin (BCG) vaccination (OR 0.5, 95% CI 0.2-1.0, p = 0.06). Of 134 contacts, 54 (40.2%) underwent 3-mo ELISPOT reversion, which was less likely in those with a positive recruitment TST (OR 0.3, 95% CI 0.1-0.8, p = 0.014). Between 3 and 18 mo, 35/132 (26.5%) contacts underwent ELISPOT conversion and 28/78 (35.9%) underwent ELISPOT reversion. Of the 210 contacts with complete results, 73 (34.8%) were ELISPOT negative at all three time points; 36 (17.1%) were positive at all three time points. Between recruitment and 18 mo, 20 (27%) contacts had ELISPOT conversion; 37 (50%) had TST conversion, which was associated with a positive recruitment ELISPOT (OR 7.2, 95% CI 1.4-37.1, p = 0.019); 18 (32.7%) underwent ELISPOT reversion; and five (8.9%) underwent TST reversion. Results in 13 contacts diagnosed as having TB were mixed, but suggested higher TST sensitivity. CONCLUSIONS: Both ELISPOT conversion and reversion occur after M. tuberculosis exposure. Rapid ELISPOT reversion may reflect M. tuberculosis clearance or transition into dormancy and may contribute to the relatively low reported ELISPOT conversion rate. Therefore, a negative ELISPOT test for M. tuberculosis infection should be interpreted with caution.

Background Repeat tuberculin skin tests may be false positive due to boosting of waned immunity to past mycobacterial exposure. We evaluated whether an ELISPOT test could identify tuberculosis (TB) contacts with boosting of immunity to non-tuberculous mycobacterial exposure. Methodology/Principal Findings We conducted tuberculin and ELISPOT tests in 1665 TB contacts: 799 were tuberculin test negative and were offered a repeat test after three months. Those with tuberculin test conversion had an ELISPOT, chest X-ray and sputum analysis if appropriate. We compared converters with non-converters, assessed the probability of each of four combinations of ELISPOT results over the two time points and estimated boosting with adjustment for ELISPOT sensitivity and specificity. 704 (72%) contacts had a repeat tuberculin test; 176 (25%) had test conversion, which increased with exposure to a case (p = 0.002), increasing age (p = 0.0006) and BCG scar (p = 0.06). 114 tuberculin test converters had ELISPOT results: 16(14%) were recruitment positive/follow-up positive, 9 (8%) positive/negative, 34 (30%) negative/positive, and 55 (48%) were negative/negative. There was a significant non-linear effect of age for ELISPOT results in skin test converters (p = 0.038). Estimates of boosting ranged from 32%–41% of skin test converters with increasing age. Three converters were diagnosed with TB, two had ELISPOT results: both were positive, including one at recruitment. Conclusions/Significance We estimate that approximately one third of tuberculin skin test conversion in Gambian TB case contacts is due to boosting of immunity to non-tuberculous mycobacterial exposure. Further longitudinal studies are required to confirm whether ELISPOT can reliably identify case contacts with tuberculin test conversion that would benefit most from prophylactic treatment.

Commercial tests measuring IFN-gamma responses to ESAT-6 and CFP-10 are available for diagnosing Mycobacterium tuberculosis infection. Measures that minimize cost and complexity will facilitate their application in less-developed countries. We investigated whether overlapping peptides representing both ESAT-6 and CFP-10 are required to detect M. tuberculosis infection in a high TB-burden country, and whether they can be combined in a single pool. ESAT-6 and CFP-10 peptides were compared in IFN-gamma enzyme-linked immunospot (ELISPOT) in 183 HIV-negative smear-positive TB cases and 1673 HIV-negative household contacts. Separate peptide pools for each antigen were compared with a combined pool in 498 contacts. Forty per cent of responsive contacts recognized both antigens, 51% only ESAT-6 and 10% only CFP-10, whereas 56% of responsive cases recognized both antigens, 30% only ESAT-6 and 13% only CFP-10. Accordingly, CFP-10 response rates were higher for TB cases (odds ratio 2.409, P

Contact investigation is a key component of tuberculosis (TB) control in developed, but not developing, countries. We aimed to measure the prevalence of TB among household contacts of sputum-smear-positive TB cases in The Gambia and to assess the sensitivity of an enzyme-linked immunospot (ELISPOT) assay in this regard. Household contacts of adult smear-positive TB patients were assessed by questionnaire, purified protein derivative (PPD) skin test, ELISPOT assay, physical examination, chest X-ray and sputum/gastric aspirate. Thirty-three TB cases were identified from 2174 of 2381 contacts of 317 adult smear-positive pulmonary TB patients, giving a prevalence of 1518/100000. The cases identified tended to have milder disease than those passively detected. The sensitivity of ESAT-6/CFP-10 ELISPOT test as a screening test for TB disease was estimated as 71%. Fifty-six per cent of contacts with a PPD skin test resultor=10mm induration had detectable responses to ESAT-6/CFP-10 by ELISPOT; 11% with a negative PPD skin test (10mm) had a positive ESAT-6/CFP-10 response. Active screening for TB among contacts of TB patients may have a role in TB control in The Gambia. These individuals are a high-risk group, and the disease identified is less advanced than that found through passive case detection. An ELISPOT assay was relatively insensitive as a screening test for TB.

OBJECTIVE. To compare the enzyme-linked immunospot (ELISPOT) assay with the tuberculin skin test (TST) in children for the diagnosis of Mycobacterium tuberculosis infection in the Gambia. METHODS. We divided child contacts of sputum smear-positive tuberculosis cases into 3 age categories ( RESULTS. In child contacts of 287 cases, 225 (32.5%) of 693 were positive by TST and 232 (32.3%) of 718 by ELISPOT. The overall agreement between tests was 83% and the discordance was not significant. Both tests responded to the M tuberculosis exposure gradient in each age category. The percentage of those who were TST positive/ELISPOT negative increased with increasing exposure. At the lowest exposure level, the percentage of ELISPOT-positive children who were TST negative was increased compared with the highest exposure level. Neither test had evidence of false positive results because of BCG. CONCLUSIONS. In Gambian children, the ELISPOT is slightly less sensitive than the TST in the diagnosis of M tuberculosis infection from recent exposure, and neither test is confounded by prior BCG vaccination. Evidence of reduced TST sensitivity in subjects with the lowest known recent M tuberculosis exposure suggests that, when maximal sensitivity is important, the 2 tests may be best used together.

Overlapping peptides of Mycobacterium tuberculosis antigens ESAT-6 and CFP-10 offer increased specificity over the purified protein derivative skin test when they were used in an ex vivo enzyme-linked immunospot (ELISPOT) assay for gamma interferon detection for the diagnosis of M. tuberculosis infection from recent exposure. We assessed whether equivalent results could be obtained for a fusion protein of the two antigens and whether a combined readout would offer increased sensitivity in The Gambia. We studied the ELISPOT assay results for 488 household contacts of 88 sputum smear-positive tuberculosis (TB) cases. The proportions of subjects positive by each test and by the tests combined were assessed across an exposure gradient, defined according to sleeping proximity to a TB case. Eighty-eight (18%) subjects were positive for CFP-10 peptides, 148 (30%) were positive for ESAT-6 peptides, 161 (33%) were positive for both peptides, and 168 (34%) were positive for the fusion protein; 188 (39%) subjects had either a positive result for a peptide or a positive result for the fusion protein. There was reasonable agreement between the peptide and the protein results (kappa statistic = 0.78) and no significant discordance ( P = 0.38). There was a strong correlation between the fusion protein and combined peptide spot counts ( r = 0.9), and responses to the peptide and the proteins all increased significantly according to M. tuberculosis exposure. The proportion of subjects positive for either the pool of peptides or the fusion protein offered maximum sensitivity, being significantly higher than the proportion of subjects positive for ESAT-6 peptides alone ( P = 0.007). A fusion protein of ESAT-6 and CFP-10 is equivalent to overlapping peptides for the diagnosis of latent M. tuberculosis infection. Use of a combination of peptides and fusion protein offers improved sensitivity.

Background New tools are required to improve tuberculosis (TB) diagnosis and treatment, including enhanced ability to compare new treatment strategies. The ELISPOT assay uses Mycobacterium tuberculosis-specific antigens to produce a precise quantitative readout of the immune response to pathogen. We hypothesized that TB patients in The Gambia would have reduced ELISPOT counts after successful treatment. Methods We recruited Gambian adults with sputum smear and culture positive tuberculosis for ELISPOT assay and HIV test, and followed them up one year later to repeat testing and document treatment outcome. We used ESAT-6, CFP-10 and Purified Protein Derivative (PPD) as stimulatory antigens. We confirmed the reliability of our assay in 23 volunteers through 2 tests one week apart, comparing within and between subject variation. Results We performed an ELISPOT test at diagnosis and 12 months later in 89 patients. At recruitment, 70/85 HIV-negative patients (82%) were ESAT-6 or CFP-10 (EC) ELISPOT positive, 77 (90%) were PPD ELISPOT positive. Eighty-two cases (96%) successfully completed treatment: 44 (55%; p < 0.001) were EC ELISPOT negative at 12 months, 17 (21%; p = 0.051) were PPD ELISPOT negative. Sixty (73%) cured cases had a CFP-10 ELISPOT count decrease, 64 (78%) had an ESAT-6 ELISPOT count decrease, 58 (70%) had a PPD ELISPOT count decrease. There was a mean decline of 25, 44 and 47 SFU/2 × 105 cells for CFP-10, ESAT-6 and PPD respectively (p < 0.001 for all). Three of 4 HIV positive patients were cured, all 3 underwent ELISPOT reversion; all 4 not cured subjects (3 HIV-negative, 1 HIV positive) were ESAT-6, CFP-10 and PPD ELISPOT positive at 12 months. Conclusion Successful tuberculosis treatment is accompanied by a significant reduction in the M. tuberculosis-specific antigen ELISPOT count. The ELISPOT has potential as a proxy measure of TB treatment outcome. Further investigation into the decay kinetics of T-cells with treatment is warranted.