Browsing by Subject "Neutropenia"

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    Open Access
    The anti-Pseudomonas aeruginosa antibody Panobacumab is efficacious on acute pneumonia in neutropenic mice and has additive effects with meropenem
    (Public Library of Science, 2013) Secher, Thomas; Fas, Stefanie; Fauconnier, Louis; Mathieu, Marieke; Rutschi, Oliver; Ryffel, Bernhard; Rudolf, Michael
    Pseudomonas aeruginosa ( P. aeruginosa ) infections are associated with considerable morbidity and mortality in immunocompromised patients due to antibiotic resistance. Therefore, we investigated the efficacy of the anti- P. aeruginosa serotype O11 lipopolysaccharide monoclonal antibody Panobacumab in a clinically relevant murine model of neutropenia induced by cyclophosphamide and in combination with meropenem in susceptible and meropenem resistant P. aeruginosa induced pneumonia. We observed that P. aeruginosa induced pneumonia was dramatically increased in neutropenic mice compared to immunocompetent mice. First, Panobacumab significantly reduced lung inflammation and enhanced bacterial clearance from the lung of neutropenic host. Secondly, combination of Panobacumab and meropenem had an additive effect. Third, Panobacumab retained activity on a meropenem resistant P. aeruginosa strain. In conclusion, the present data established that Panobacumab contributes to the clearance of P. aeruginosa in neutropenic hosts as well as in combination with antibiotics in immunocompetent hosts. This suggests beneficial effects of co-treatment even in immunocompromised individuals, suffering most of the morbidity and mortality of P. aeruginosa infections.
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    Open Access
    Diamond–Blackfan anemia RPL35A: a case report
    (2019-06-18) Noel, Colin B
    Background Diamond–Blackfan anemia is a rare congenital red blood cell aplasia characterized by failed erythropoiesis, congenital abnormalities in up to 50% of patients, growth retardation in up to 30% of patients, and a predisposition to malignancy. Diamond–Blackfan anemia is both clinically and genetically a heterogenous condition ranging from subtle asymptomatic erythroid abnormalities to non-immune hydrops fetalis. Current treatment options include corticosteroid therapy, chronic red blood cell transfusions, and hematopoietic stem cell transplantation with gene therapy receiving recent attention. We report the first documented case of Diamond–Blackfan anemia in a Caucasian girl secondary to a sporadic heterozygous whole gene deletion in RPL35A in South Africa. Limited resources, non-availability of tests, unfamiliarity that comes with rare diseases, an expanded differential diagnosis, and an associated neutropenia led to a delay in the diagnosis of Diamond–Blackfan anemia. This case reminds clinicians of Diamond–Blackfan anemia as a cause of aplastic anemia and highlights the difficulty and obstacles in diagnosing Diamond–Blackfan anemia in resource-limited countries. Case presentation We report a case of a 6-week-old Caucasian girl presenting with urosepsis and heart failure secondary to a severe anemia and neutropenia. Limited experience and resources resulted in a delay in diagnosis. Genetic studies later confirmed a heterozygous whole gene deletion of RPL35A. Initial treatment was directed toward correcting the anemia with red blood cell transfusion every 3 to 5 weeks. Conclusion Diamond–Blackfan anemia is a rare disease that carries significant morbidity and mortality if not diagnosed early and managed appropriately. Limited health resources, patient registries, and specialists as seen in developing countries result in a paucity of knowledge about Diamond–Blackfan anemia in Africa. This case reminds clinicians about Diamond–Blackfan anemia as a cause for anemia in infants, the limitations in making the diagnosis in under-resourced health care systems, and the need for standardized treatment protocols applicable to resource-limited countries.
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    Randomized pharmacokinetic evaluation of different rifabutin doses in African HIV- infected tuberculosis patients on lopinavir/ritonavir-based antiretroviral therapy
    (2014-11-19) Naiker, Suhashni; Connolly, Cathy; Wiesner, Lubbe; Kellerman, Tracey; Reddy, Tarylee; Harries, Anthony; McIlleron, Helen; Lienhardt, Christian; Pym, Alexander
    Abstract Background Pharmacokinetic interactions between rifampicin and protease inhibitors (PIs) complicate the management of HIV-associated tuberculosis. Rifabutin is an alternative rifamycin, for patients requiring PIs. Recently some international guidelines have recommended a higher dose of rifabutin (150 mg daily) in combination with boosted lopinavir (LPV/r), than the previous dose of rifabutin (150 mg three times weekly {tiw}). But there are limited pharmacokinetic data evaluating the higher dose of rifabutin in combination with LPV/r. Sub-optimal dosing can lead to acquired rifamycin resistance (ARR). The plasma concentration of 25-O-desacetylrifabutin (d-RBT), the metabolite of rifabutin, increases in the presence of PIs and may lead to toxicity. Methods and results Sixteen patients with TB-HIV co-infection received rifabutin 300 mg QD in combination with tuberculosis chemotherapy (initially pyrazinamide, isoniazid and ethambutol then only isoniazid), and were then randomized to receive isoniazid and LPV/r based ART with rifabutin 150 mg tiw or rifabutin 150 mg daily. The rifabutin dose with ART was switched after 1 month. Serial rifabutin and d-RBT concentrations were measured after 4 weeks of each treatment. The median AUC0–48 and Cmax of rifabutin in patients taking 150 mg rifabutin tiw was significantly reduced compared to the other treatment arms. Geometric mean ratio (90% CI) for AUC0–48 and Cmax was 0.6 (0.5-0.7) and 0.5 (0.4-0.6) for RBT 150 mg tiw compared with RBT 300 mg and 0.4 (0.4-0.4) and 0.5 (0.5-0.6) for RBT 150 mg tiw compared with 150 mg daily. 86% of patients on the tiw rifabutin arm had an AUC0-24 < 4.5 μg.h/mL, which has previously been associated with acquired rifamycin resistance (ARR). Plasma d-RBT concentrations increased 5-fold with tiw rifabutin dosing and 15-fold with daily doses of rifabutin. Rifabutin was well tolerated at all doses and there were no grade 4 laboratory toxicities. One case of uveitis (grade 4), occurred in a patient taking rifabutin 300 mg daily prior to starting ART, and grade 3 neutropenia (asymptomatic) was reported in 4 patients. These events were not associated with increases in rifabutin or metabolite concentrations. Conclusions A daily 150 mg dose of rifabutin in combination with LPV/r safely maintained rifabutin plasma concentrations in line with those shown to prevent ARR. Trial registration ClinicalTrials.gov Identifier: NCT00640887