56 research outputs found

    Anti-mycobacterial recall responses differentiate female patients with genital tuberculosis from patients with other gynecological problems

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    Background: Female Genital Tuberculosis (FGTB) is one form of extra pulmonary tuberculosis affecting the female reproductive organs, most commonly the fallopian tubes and the endometrium. It affects young women aged between 20 and 40 years of age and is an important cause of infertility. It often occurs as a secondary complication following pulmonary tuberculosis. Diagnosis depends mainly on clinical suspicion in countries where facilities for mycobacterial culture and histopathology are unavailable. Even in places where these facilities exist, diagnosis still remains difficult because of the lower sensitivity and specificity of the methods as well as the invasive procedure of acquiring biopsy specimens. Objective: To explore the immunological profiles of female genital tuberculosis (FGTB) patients in response to mycobacterial antigens. Methods: Twenty-five clinically suspected cases of FGTB and 12 control subjects who came to the Black Lion hospital for unrelated gynecological problems were included in the study. Peripheral blood samples were collected from each subject. Plasma was separated by centrifugation and PBMC were isolated over ficoll-hypaque and stimulated in vitro with mycobacterial antigens to examine their proliferative response as incorporation of tritiated thymidine using a β-counter. HIV status and total IgG-, IgA- and IgM- antibody levels were determined by ELISA tests.Results: In vitro recall responses to M. tuberculosis antigens (PPD and BCG sonicate) as well as plasma levels of IgGIgA- and IgM-antibodies to MPT59 showed statistically significant differences between the patients and the controls (

    High CD56++CD16- natural killer (NK) cells among suboptimal immune responders after four years of suppressive antiretroviral therapy in an African adult HIV treatment cohort

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    BACKGROUND: Up to 40% of HIV-infected individuals receiving Highly Active Antiretroviral Therapy (HAART) have poor CD4+ T-cell recovery. The role of natural killer (NK) cells in immune recovery during HAART is not well understood. We described the profiles of NK cell subsets and their expression of activating receptor, NKG2D and cytotoxicity receptor NKp46 among suboptimal immune responders to despite four years of suppressive HAART. METHODS: A case control study utilized frozen peripheral blood mononuclear cells (PBMC) from a cohort of HIV-infected adults that initiated HAART in 2004/5, at CD4 < 200 cells/μl. Cases were ‘suboptimal’ responders; patients within the lowest quartile of CD4+ T-cell reconstitution, with a median CD4 count increase of 129 (-43-199) cells/μl (difference between CD4 count at baseline and after 4 years of HAART) and controls were ‘super-optimal’ responders; patients within the highest quartile of CD4 T-cell reconstitution with a median CD4 count increase of 528 (416-878) cells/μl). Expression of NK cell lineage markers (CD56(+/-)CD16(+/-)) and receptors NKG2D and NKp46, was measured among PBMC from 29 cases of ‘suboptimal’ responders’ and 23 controls of ‘super-optimal responders’, and compared among ‘suboptimal’ and ‘super-optimal’ responders. NK cell populations were compared using the Holm Sidak multiple comparison test and p values < 0.05 were considered statistically significant. Data was analyzed using FLOWJO and GraphPad Prism 6. RESULTS: ‘Suboptimal responders’ had a higher proportion of cytokine producing CD56(++)CD16(+/-) (CD56(bri)) NK cells than the ‘super-optimal responders’ p = 0.017, and CD56(neg) NK cells were lower among suboptimal than super-optimal responders (p = 0.007). The largest NK cell subset, CD56(dim), was comparable among suboptimal responders and ‘super-optimal immune responders’. Expression of NKG2D and NKp46 receptors on NK cell subsets (CD56(bri), CD56(neg) and CD56(dim)), was comparable among ‘suboptimal’ and ‘super-optimal’ immune responders. CONCLUSIONS: The pro-inflammatory CD56(++)CD16(--) NK cells were higher among ‘suboptimal’ responders relative to ‘super-optimal’ responders, despite four years of suppressive HAART. Alteration of NK cell populations could inhibit host immune responses to infections among suboptimal responders. We recommend further analysis of NK cell function among suboptimal immune responders in order to inform targeted interventions to optimize immune recovery among HAART-treated adults

    Blood Parasite Load as an Early Marker to Predict Treatment Response in Visceral Leishmaniasis in Eastern Africa

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    Background: To expedite the development of new oral treatment regimens for visceral leishmaniasis (VL), there is a need for early markers to evaluate treatment response and predict long-term outcomes. Methods: Data from 3 clinical trials were combined in this study, in which Eastern African VL patients received various antileishmanial therapies. Leishmania kinetoplast DNA was quantified in whole blood with real-time quantitative polymerase chain reaction (qPCR) before, during, and up to 6 months after treatment. The predictive performance of pharmacodynamic parameters for clinical relapse was evaluated using receiver-operating characteristic curves. Clinical trial simulations were performed to determine the power associated with the use of blood parasite load as a surrogate endpoint to predict clinical outcome at 6 months. Results: The absolute parasite density on day 56 after start of treatment was found to be a highly sensitive predictor of relapse within 6 months of follow-up at a cutoff of 20 parasites/mL (area under the curve 0.92, specificity 0.91, sensitivity 0.89). Blood parasite loads correlated well with tissue parasite loads (ρ = 0.80) and with microscopy gradings of bone marrow and spleen aspirate smears. Clinical trial simulations indicated a > 80% power to detect a difference in cure rate between treatment regimens if this difference was high (> 50%) and when minimally 30 patients were included per regimen. Conclusions: Blood Leishmania parasite load determined by qPCR is a promising early biomarker to predict relapse in VL patients. Once optimized, it might be useful in dose finding studies of new chemical entities.This work was supported by the European Union Seventh Framework Programme Africoleish (grant number 305178); the World Health Organization—Special Programme for Research and Training in Tropical Diseases (WHO-TDR); the French Development Agency, France (grant number CZZ2062); UK aid, UK; the Federal Ministry of Education and Research through KfW, Germany; the Medicor Foundation, Liechtenstein; Médecins Sans Frontières, International; the Swiss Agency for Development and Cooperation (SDC), Switzerland (grant number 81017718); the Dutch Ministry of Foreign Affairs (DGIS), the Netherlands (grant number PDP15CH21); the French Ministry for Europe and Foreign Affairs (MEAE), France; The Rockefeller Foundation, USA; BBVA Foundation, Spain; the European Union—AfriKADIA project of the Second European and Developing Countries Clinical Trials Partnership Programme (EDCTP2) (grant number RIA2016S1635); and ZonMw/Dutch Research Council (NWO) Veni grant (project number 91617140 to T. P. C. D.).S

    Population pharmacokinetics of a combination of miltefosine and paromomycin in Eastern African children and adults with visceral leishmaniasis

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    Objectives: To improve visceral leishmaniasis (VL) treatment in Eastern Africa, 14-and 28-day combination regimens of paromomycin plus allometrically dosed miltefosine were evaluated. As the majority of patients affected by VL are children, adequate paediatric exposure to miltefosine and paromomycin is key to ensuring good treatment response. Methods: Pharmacokinetic data were collected in a multicentre randomized controlled trial in VL patients from Kenya, Sudan, Ethiopia and Uganda. Patients received paromomycin (20 mg/kg/day for 14 days) plus miltefosine (allometric dose for 14 or 28 days). Population pharmacokinetic models were developed. Adequacy of exposure and target attainment of paromomycin and miltefosine were evaluated in children and adults. Results: Data from 265 patients (59% ≤12 years) were available for this pharmacokinetic analysis. Paromomycin exposure was lower in paediatric patients compared with adults [median (IQR) end-of-Treatment AUC0-24h 187 (162-203) and 242 (217-328) μg·h/mL, respectively], but were both within the IQR of end-of-Treatment exposure in Kenyan and Sudanese adult patients from a previous study. Cumulative miltefosine end-of-Treatment exposure in paediatric patients and adults [AUCD0-28 517 (464-552) and 524 (456-567) μg·day/mL, respectively] and target attainment [time above the in vitro susceptibility value EC90 27 (25-28) and 30 (28-32) days, respectively] were comparable to previously observed values in adults. Conclusions: Paromomycin and miltefosine exposure in this new combination regimen corresponded to the desirable levels of exposure, supporting the implementation of the shortened 14 day combination regimen. Moreover, the lack of a clear exposure-response and exposure-Toxicity relationship indicated adequate exposure within the therapeutic range in the studied population, including paediatric patients

    Efficacy and Safety of AmBisome in Combination with Sodium Stibogluconate or Miltefosine and Miltefosine Monotherapy for African Visceral Leishmaniasis: Phase II Randomized Trial.

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    BACKGROUND: SSG&PM over 17 days is recommended as first line treatment for visceral leishmaniasis in eastern Africa, but is painful and requires hospitalization. Combination regimens including AmBisome and miltefosine are safe and effective in India, but there are no published data from trials of combination therapies including these drugs from Africa. METHODS: A phase II open-label, non-comparative randomized trial was conducted in Sudan and Kenya to evaluate the efficacy and safety of three treatment regimens: 10 mg/kg single dose AmBisome plus 10 days of SSG (20 mg/kg/day), 10 mg/kg single dose AmBisome plus 10 days of miltefosine (2.5mg/kg/day) and miltefosine alone (2.5 mg/kg/day for 28 days). The primary endpoint was initial parasitological cure at Day 28, and secondary endpoints included definitive cure at Day 210, and pharmacokinetic (miltefosine) and pharmacodynamic assessments. RESULTS: In sequential analyses with 49-51 patients per arm, initial cure was 85% (95% CI: 73-92) in all arms. At D210, definitive cure was 87% (95% CI: 77-97) for AmBisome + SSG, 77% (95% CI 64-90) for AmBisome + miltefosine and 72% (95% CI 60-85) for miltefosine alone, with lower efficacy in younger patients, who weigh less. Miltefosine pharmacokinetic data indicated under-exposure in children compared to adults. CONCLUSION: No major safety concerns were identified, but point estimates of definitive cure were less than 90% for each regimen so none will be evaluated in Phase III trials in their current form. Allometric dosing of miltefosine in children needs to be evaluated. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov, number NCT01067443

    Sodium Stibogluconate (SSG) & Paromomycin Combination Compared to SSG for Visceral Leishmaniasis in East Africa: A Randomised Controlled Trial

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    Visceral leishmaniasis (VL) is a parasitic disease with about 500,000 new cases each year and is fatal if untreated. The current standard therapy involves long courses, has toxicity and there is evidence of increasing resistance. New and better treatment options are urgently needed. Recently, the antibiotic paromomycin (PM) was tested and registered in India to treat this disease, but the same dose of PM monotherapy evaluated and registered in India was not efficacious in Sudan. This article reports the results of a clinical trial to test the effectiveness of injectable PM either alone (in a higher dose) or in combination with sodium stibogluconate (SSG) against the standard SSG monotherapy treatment in four East African countries—Sudan, Kenya, Ethiopia and Uganda. The study showed that the combination of SSG &PM was as efficacious and safe as the standard SSG treatment, with the advantages of being cheaper and requiring only 17 days rather than 30 days of treatment. In March 2010, a WHO Expert Committee recommended the use of the SSG & PM combination as a first line treatment for VL in East Africa

    Evaluation of poliovirus antibody titers in orally vaccinated semi-captive chimpanzees in Uganda

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    Background: To understand immunological responses in chimpanzees vaccinated with live-attenuated vaccine (oral polio vaccine; OPV), serum neutralizing antibodies against poliovirus types 1, 2, and 3 were investigated over time. Methods: The neutralizing antibody titers against poliovirus types 1, 2, and 3 were determined by microneutralization test using 100 ID50 of poliovirus types 1, 2, and 3 (Sabin strains). Results: Neutralizing antibodies against poliovirus types 1, 2, and 3 were detected in 85.7%, 71.4%, and 65% of the serum from 42 chimpanzees tested 9 years post-vaccination. The neutralizing antibody titers in chimpanzees were similar to the documented levels in human studies as an indicator of vaccine efficacy. Conclusions: This study reveals persistence of neutralizing antibodies in chimpanzees for at least 9 years after vaccination with OPV. This first study in chimpanzees provides useful information for the evaluation of the success of vaccination with OPV in other captive apes

    Predicted role of small non-coding Ribonucleic acids (ncRNAs) and Ribonucleoproteins (RNPs) in Influenza genetic shifts and drifts

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    ABSTRACT Objective: Influenza disease has been observed to be severe in animal hosts in associations with coinfection with H.Influenza species. This phenomenon is widely related to H.Influenza associated inflammation, but may as well be due to emergence of new virus strains. If the later is true, then H. Influenza may be releasing modulators of Influenza genomic variation aside of innate virus&apos; error prone polymerase. Group II Retroposon elements (RTE) are a mobile class of small noncoding RNAs (snRNA) with both RNA and DNA catalytic potential found distributed across organella genomes, eubacteria and archeabacteria. To aimed to investigate if H. Influenza RTE derived snRNA may be exogenous mediators of Influenza genomic splicing Methodology and Results: we employed Insilco palindromics to search for potential cleavage sites in 8 Influenza genomic RNA segments using 14 H. Influenza derived REases; AND a search for ORF encoding RT, X and En domains in 16 H. influenza species genome databases by BLASTP with query H.s.I1. Palindromes were found distributed in order of polymerase acidic protein gene PA 14 (100%), S2 13 (93%); HA;7 (50%), NA;7 (50%), PB1;8 (57%), PB2;7 (50%), M1&amp;2;10 (71%), S1;8 (57%), S3;9 (64%), S4;7 (50%), S5;7 (50%), S6;7 (50%), S7;6 (43%), S8;6 (43%), NP;4 (29%), and the NS1&amp;2;3 (21%). 15 low score blast hits were found, 7 of which were MTase-subunits of putative type I R-M systems, but no ortholog of the H.s.I1 ORF except in the query source genome H.somnus. Conclusions: While the distribution of Palindromes supports the existence of HNHc/HHVR cleavage sites in Influenza RNA, the role of Group II RTE snRNA in drifts and shifts is limited by lack of conclusive homologs of RT ORF. Key words: Group II Retroelements; Haemophilus Influenza species; Influenza antigenic drifts and reassortments; Restriction Endonuclease (REases). Abbreviations: DNA-Deoxyribonucleic acid; RNA-Ribonucleic acids; NA-Neuraminidase; HA-Haemagglutinin; PAPolymerase acidic protein; PB1&amp;2-Polymerase basic proteins 1&amp;2; M1,2-Matrix proteins 1,2; S1-8-genomic RNA segments 1-8; NP-Nucleoprotein; NS1&amp;2-Non-structural proteins 1&amp;2, RM -Restriction modification: This paper has supplementary files that can be accessed on a separate link provided next to the paper title at the journal website

    Retroviruses in Wild-Born Semi-Captive East African Sanctuary Chimpanzees (Pan troglodytes schweinfurthii)

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    Information on retroviruses infections in great apes is scarce, especially for apes kept in sanctuaries throughout Africa. To investigate the prevalence of retroviruses and possible transmission of different retroviruses originating from chimpanzees of different origin (Uganda, Congo and Rwanda), 38 wild-born captive orphan chimpanzees residing in a sanctuary on Ngamba Island were analyzed for retroviral infections. Samples from sanctuary chimpanzees were analyzed using enzyme-linked immunoassays and polymerase chain reactions (PCR). Viruses were characterized by phylogenetic analysis. All chimpanzees were negative for antibodies against Simian Immunodeficiency Virus (SIV) and Simian T-cell Leukemia Virus (STLV). However, 28/38 (73%) chimpanzees were positive to Simian Foamy Virus (SFV) by analysis of a 425-bp DNA segment obtained by PCR using generic integrase primers homologous to highly conserved portions of the polymerase gene. Phylogenetic analysis of SFV sequences obtained in this study formed four sub clusters within the specific SFV P. t. schweinfurthii clade with significant variability among the new SFVs strains. We provide evidence of on-going cross-transmission of SFV among chimpanzees within the sanctuary mostly likely through horizontal routes. We propose to test all chimpanzees introduced into sanctuaries for retroviral and other infections. This will help avoid the spread also of pathogenic viruses in captive populations

    Immune Responses to the Mycobacterium tuberculosis-Specific Antigen ESAT-6 Signal Subclinical Infection among Contacts of Tuberculosis Patients

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    Diagnosis of latent Mycobacterium tuberculosis infection is considered essential for tuberculosis control but is hampered by the lack of specific reagents. We report that strong recognition of tuberculosis complex-specific antigen ESAT-6 by healthy household contacts of tuberculosis patients correlates with the subsequent development of active tuberculosis during a 2-year follow-up period
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