Plasma Levels of Neopterin and C-Reactive Protein (CRP) in Tuberculosis (TB) with and without HIV Coinfection in Relation to CD4 Cell Count

Background While the risk of TB is elevated in HIV-positive subjects with low CD4 cell counts, TB may in itself be associated with CD4 lymphocytopenia. We investigated markers of immune activation (neopterin) and inflammation (CRP) in TB patients with and without HIV coinfection and their association with CD4 cell levels, and determined their predictive capacity as alternative markers of advanced immunosuppression. Methods Participants selected from a cohort of adults with TB at Ethiopian health centers (195 HIV +/TB+, 170 HIV-/TB+) and 31 controls were tested for plasma levels of neopterin and CRP. Baseline levels of neopterin and CRP were correlated to CD4 cell count before and after anti-TB treatment (ATT). The performance to predict CD4 cell strata for both markers were investigated using receiver operating curves. Results Levels of both biomarkers were elevated in TB patients (neopterin: HIV+/TB+ 54 nmol/l, HIV-/TB+ 23 nmol/l, controls 3.8 nmol/l; CRP: HIV+/TB+ 36 mu g/ml, HIV-/TB+ 33 mu g/ml, controls 0.5 mu g/ml). Neopterin levels were inversely correlated (-0.53, p&amp;lt;0.001) to CD4 cell count, whereas this correlation was weaker for CRP (-0.25, p&amp;lt;0.001). Neither of the markers had adequate predictive value for identification of subjects with CD4 cell count &amp;lt;100 cells/mm(3) (area under the curve [AUC] 0.64 for neopterin, AUC 0.59 for CRP). Conclusion Neopterin levels were high in adults with TB, both with and without HIV coinfection, with inverse correlation to CD4 cell count. This suggests that immune activation may be involved in TB-related CD4 lymphocytopenia. However, neither neopterin nor CRP showed promise as alternative tests for immunosuppression in patients coinfected with HIV and TB.Funding Agencies|Swedish Civil Contingency Agency; Swedish International Development Cooperation Agency; Region Skane; Swedish Medical Association</p

A borderline range for Quantiferon Gold In-Tube results

Objective Interferon gamma release assays like Quantiferon Gold In-Tube (QFT) are used to identify individuals infected with Mycobacterium tuberculosis. A dichotomous cut-off (0.35 IU/ml) defines a positive QFT without considering test variability. Our objective was to evaluate the introduction of a borderline range under routine conditions. Methods Results of routine QFT samples from Sweden (2009-2014) were collected. A borderline range (0.20-0.99 IU/ml) was introduced in 2010 recommending a follow-up sample. The association between borderline results and incident active TB within 3 to 24 months was investigated through linkage with the national TB-register. Results Using the recommended QFT cut-off, 75.1 % tests were negative, 21.4% positive and 3.5% indeterminate. In total, 9% (3656/40773) were within the borderline range. In follow-up samples, individuals with initial results between 0.20-0.34 IU/ml and 0.35-0.99 IU/ml displayed negative results below the borderline range (amp;lt;0.20 IU/ml) in 66.1% (230/348) and 42.5% (285/671) respectively, and none developed incident TB. Among 6712 individuals with a positive initial test amp;gt;0.99 IU/ml, 65 (0.97%) developed incident TB within 3-24 months. Conclusions We recommend retesting of subjects with QFT results in the range 0.20-0.99 IU/ml to enhance reliability and validity of the test. Half of the subjects in the borderline range will be negative at a levelamp;lt;0.20 IU/ml when retested and have a very low risk of developing incident active TB.Funding Agencies|Swedish Research council [201602043]; Swedish Heart and Lung Foundation (Oscar II Jubilee foundation) [20150236, 20150237]</p

Pregnancy Outcomes in Women Screened for Tuberculosis Infection in Swedish Antenatal Care

Background. Tuberculosis (TB) disease has been associated with pregnancy complications. However, the potential impact of TB infection (TBI) on pregnancy outcome is unknown. To investigate this, we conducted a register-based study in immigrant women screened with QuantiFERON assays for TBI in antenatal care in Sweden.Methods. Women with history of immigration from TB-endemic countries were eligible for inclusion if national identification numbers and available QuantiFERON results obtained during pregnancy from 2014 to 2018 were available. QuantiFERON results were linked to data on maternal characteristics and pregnancy outcomes from the national Pregnancy and Patient Registers. TBI was defined as nil-corrected QuantiFERON result &amp; GE;0.35 IU/mL, in the absence of TB disease. Pregnancies in women with TB disease or human immunodeficiency virus were excluded, as were multiplex pregnancies, pregnancies resulting in miscarriage, and pregnancies occurring &amp;gt;10 years after immigration. Odds of defined adverse pregnancy outcomes were compared by maternal TBI status using mixed effects logistic regression with adjustment for maternal age and region of origin.Results. In total, 7408 women with 12 443 pregnancies were included. In multivariable analysis, stillbirth (adjusted odds ratio [AOR], 1.90; 95% confidence interval [CI], 1.13-3.21; P = .016), severe preeclampsia (AOR, 1.62; 95% CI, 1.03-2.56; P = .036), low birthweight (&amp;lt;2500 g; AOR, 1.38; 95% CI, 1.01-1.88; P = .041), and emergency cesarean section (AOR, 1.28; 95% CI, 1.02-1.63; P = .033) were significantly associated with TBI.Conclusions. Among immigrant women seeking antenatal care in Sweden, TBI was independently associated with adverse pregnancy outcomes. Further studies are needed to corroborate these findings and to explore mechanisms involved.Funding Agencies|Swedish Heart-Lung Foundation [20170258]; Crafoord Foundation [20170537]; Alfred Osterlund Foundation; Region Skane research grants [41509]; governmental funding of clinical research within the National Health Services Sweden, ALF-agreement [40103]; Centralsjukhuset Kristianstad [2019-F016]</p

Transmission dynamics study of tuberculosis isolates with whole genome sequencing in southern Sweden

Epidemiological contact tracing complemented with genotyping of clinical Mycobacterium tuberculosis isolates is important for understanding disease transmission. In Sweden, tuberculosis (TB) is mostly reported in migrant and homeless where epidemiologic contact tracing could pose a problem. This study compared epidemiologic linking with genotyping in a low burden country. Mycobacterium tuberculosis isolates (n = 93) collected at Scania University Hospital in Southern Sweden were analysed with the standard genotyping method mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR) and the results were compared with whole genome sequencing (WGS). Using a maximum of twelve single nucleotide polymorphisms (SNPs) as the upper threshold of genomic relatedness noted among hosts, we identified 18 clusters with WGS comprising 52 patients with overall pairwise genetic maximum distances ranging from zero to nine SNPs. MIRU-VNTR and WGS clustered the same isolates, although the distribution differed depending on MIRU-VNTR limitations. Both genotyping techniques identified clusters where epidemiologic linking was insufficient, although WGS had higher correlation with epidemiologic data. To summarize, WGS provided better resolution of transmission than MIRU-VNTR in a setting with low TB incidence. WGS predicted epidemiologic links better which could consolidate and correct the epidemiologically linked cases, avoiding thus false clustering

Intensified Tuberculosis Case-Finding in HIV-Positive Adults Managed at Ethiopian Health Centers: Diagnostic Yield of Xpert MTB/RIF Compared with Smear Microscopy and Liquid Culture

Background: Detection of active tuberculosis (TB) before antiretroviral therapy (ART) initiation is important, but optimal diagnostic methods for use in resource-limited settings are lacking. We assessed the prevalence of TB, evaluated the diagnostic yield of Xpert MTB/RIF in comparison with smear microscopy and culture, and the impact of Xpert results on clinical management in HIV-positive adults eligible for ART at health centers in a region of Ethiopia. Methods: Participants were prospectively recruited and followed up at 5 health centers. Trained nurses collected data on socio-demographic characteristics, medical history and symptoms, and performed physical examination. Two paired morning sputum samples were obtained, and lymph node aspirates in case of lymphadenopathy. Diagnostic yield of Xpert MTB/RIF in sputum was compared with smear microscopy and liquid culture. Results: TB was diagnosed in 145/812 participants (17.9%), with bacteriological confirmation in 137 (16.9%). Among bacteriologically confirmed cases, 31 were smear-positive (22.6%), 96 were Xpert-positive (70.1%), and 123 were culture-positive (89.8%). Xpert MTB/RIF increased the TB detection rate by 64 cases (47.4%) compared with smear microscopy. The overall sensitivity of Xpert MTB/RIF was 66.4%, and was not significantly lower when testing one compared with two samples. While Xpert MTB/RIF was 46.7% sensitive among patients with CD4 cell counts greater than200 cells/mm(3), this increased to 82.9% in those with CD4 cell counts less than= 100 cells/mm(3). Compared with Xpert-positive TB patients, Xpert-negative cases had less advanced HIV and TB disease characteristics. Conclusions: Previously undiagnosed TB is common among HIV-positive individuals managed in Ethiopian health centers. Xpert MTB/RIF increased TB case detection, especially in patients with advanced immunosuppression. An algorithm based on the use of a single morning sputum sample for individuals with negative sputum smear microscopy could be considered for intensified case finding in patients eligible for ART. However, technical and cost-effectiveness issues relevant for low-income countries warrant further study

Intensified Tuberculosis Case-Finding in HIV-Positive Adults Managed at Ethiopian Health Centers: Diagnostic Yield of Xpert MTB/RIF Compared with Smear Microscopy and Liquid Culture

Background: Detection of active tuberculosis (TB) before antiretroviral therapy (ART) initiation is important, but optimal diagnostic methods for use in resource-limited settings are lacking. We assessed the prevalence of TB, evaluated the diagnostic yield of Xpert MTB/RIF in comparison with smear microscopy and culture, and the impact of Xpert results on clinical management in HIV-positive adults eligible for ART at health centers in a region of Ethiopia. Methods: Participants were prospectively recruited and followed up at 5 health centers. Trained nurses collected data on socio-demographic characteristics, medical history and symptoms, and performed physical examination. Two paired morning sputum samples were obtained, and lymph node aspirates in case of lymphadenopathy. Diagnostic yield of Xpert MTB/RIF in sputum was compared with smear microscopy and liquid culture. Results: TB was diagnosed in 145/812 participants (17.9%), with bacteriological confirmation in 137 (16.9%). Among bacteriologically confirmed cases, 31 were smear-positive (22.6%), 96 were Xpert-positive (70.1%), and 123 were culture-positive (89.8%). Xpert MTB/RIF increased the TB detection rate by 64 cases (47.4%) compared with smear microscopy. The overall sensitivity of Xpert MTB/RIF was 66.4%, and was not significantly lower when testing one compared with two samples. While Xpert MTB/RIF was 46.7% sensitive among patients with CD4 cell counts greater than200 cells/mm(3), this increased to 82.9% in those with CD4 cell counts less than= 100 cells/mm(3). Compared with Xpert-positive TB patients, Xpert-negative cases had less advanced HIV and TB disease characteristics. Conclusions: Previously undiagnosed TB is common among HIV-positive individuals managed in Ethiopian health centers. Xpert MTB/RIF increased TB case detection, especially in patients with advanced immunosuppression. An algorithm based on the use of a single morning sputum sample for individuals with negative sputum smear microscopy could be considered for intensified case finding in patients eligible for ART. However, technical and cost-effectiveness issues relevant for low-income countries warrant further study

Five month persistence of Helicobacter pylori infection in guinea pigs

Seven Dunkin-Hartley guinea pigs were infected with the Sydney strain of H. pylori (SS1). Gastric histopathology was evaluated and serum antibody response to H. pylori cell-surface proteins was analysed by enzyme immunoassay (EIA) and immunoblot. Tissue and faecal samples from five control animals were analysed for the presence of naturally occurring Helicobacter spp. infection by culture and Helicobacter genus-specific PCR. The H. pylori infection persisted for 5 months, in most animals accompanied by a histologically severe antral gastritis, exhibiting focal degeneration and necrosis of gastric crypt epithelium. Increased numbers of mitotic figures were observed in the gastric epithelium, indicating a regenerative process. Infected animals displayed specific antibodies towards H. pylori cell-surface proteins in immunoblot, whereas EIA was of dubious value creating false-positive results. Serum complement C3 and cholesterol levels appeared to be elevated in infected animals. Helicobacter spp. infection was not detected in the control animals. The persistent infection, accompanied by severe gastritis and a prominent serum antibody response, and the apparent absence of a natural Helicobacter spp. infection makes the guinea pig model useful in H. pylori research