Norma Pérez

Phase I Study Assessing the Pharmacokinetic Profile, Safety, and Tolerability of a Single Dose of Ceftazidime-Avibactam in Hospitalized Pediatric Patients

ABSTRACT This study aimed to investigate the pharmacokinetics (PK), safety, and tolerability of a single dose of ceftazidime-avibactam in pediatric patients. A phase I, multicenter, open-label PK study was conducted in pediatric patients hospitalized with an infection and receiving systemic antibiotic therapy. Patients were enrolled into four age cohorts (cohort 1, ≥12 to <18 years; cohort 2, ≥6 to <12 years; cohort 3, ≥2 to <6 years; cohort 4, ≥3 months to <2 years). Patients received a single 2-h intravenous infusion of ceftazidime-avibactam (cohort 1, 2,000 to 500 mg; cohort 2, 2,000 to 500 mg [≥40 kg] or 50 to 12.5 mg/kg [<40 kg]; cohorts 3 and 4, 50 to 12.5 mg/kg). Blood samples were collected to describe individual PK characteristics for ceftazidime and avibactam. Population PK modeling was used to describe characteristics of ceftazidime and avibactam PK across all age groups. Safety and tolerability were assessed. Thirty-two patients received study drug. Mean plasma concentration-time curves, geometric mean maximum concentration (Cmax), and area under the concentration-time curve from time zero to infinity (AUC0–∞) were similar across all cohorts for both drugs. Six patients (18.8%) reported an adverse event, all mild or moderate in intensity. No deaths or serious adverse events occurred. The single-dose PK of ceftazidime and avibactam were comparable between each of the 4 age cohorts investigated and were broadly similar to those previously observed in adults. No new safety concerns were identified. (This study has been registered at ClinicalTrials.gov under registration no. NCT01893346.)

Angiostrongylus cantonensis Meningitis and Myelitis, Texas, USA

Infection with Angiostrongylus cantonensis roundworms is endemic in Southeast Asia and the Pacific Basin. A. cantonensis meningitis and myelitis occurred in summer 2013 in a child with no history of travel outside of Texas, USA. Angiostrongyliasis is an emerging neurotropic helminthic disease in Texas and warrants increased awareness among healthcare providers.

Persistently high perinatal transmission of HIV: assessment of risk factors.

Background: Despite dramatic decreases in rates of perinatal mother-to-child-transmission (PMTCT) of HIV in the United States, rates in some groups remain above the national average. Our objective was to examine factors contributing to a high rate of PMTCT of HIV. Methods: We conducted a retrospective chart review of HIV-exposed infants and their mothers referred to the University of Texas-Houston Pediatric HIV Clinic from January 2000 to June 2007. Results: Of 367 newborns studied, 22 (6%) acquired HIV infection perinatally. Associated risk factors included inadequate prenatal care, failure to receive antiretroviral therapy during pregnancy, detectable viral load and intravenous drug abuse. Conclusions: The composite rate of PMTCT in this high risk cohort was at least 3-fold higher than expected from the current standard of care. Reduction of rates of PMTCT in our population will require ensuring access to appropriate prenatal care, including delivery of antiretroviral therapy and addressing issues of illicit drug use.

Prevalence and risk factors associated with resistance-associated mutations to etravirine in a cohort of perinatally HIV-infected children

BACKGROUNDnEtravirine is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) with reduced cross-resistance to first-generation NNRTIs. Because many perinatally HIV-infected patients have been treated with first-generation NNRTIs, they may have acquired resistance-associated mutations to etravirine (RAMe).nnnMETHODSnWe determined for the interval 1998-2009 the prevalence and factors associated with the presence of RAMe.nnnRESULTSnTwenty-three of 66 (34.8%) children had RAMe; the most common were 181C (19.6%), 190A (7.5%), 98G (6%), 106I (4.5%), 179D (4.5%), 100I (3%), 181I (1.5%), 138A (1.5%) and 179T (1.5%). Eleven children with RAMe (17%) had a mutation score between 2.5 and 3.5 and 1 (1.5%) a score ≥4, indicating an intermediate and reduced response to etravirine. For each 1% increase in CD4% there is a 7% decrease in the odds of RAMe (OR 0.93; 95% CI 0.88-0.97; P < 0.01). History of nevirapine use (OR 8.95; 95% CI 2.31-34.73; P < 0.01) and Hispanic ethnicity (OR 4.76; 95% CI 1.03-21.87; P = 0.04) are significantly associated with risk of RAMe.nnnCONCLUSIONSnRAMe are present and common among antiretroviral-experienced perinatally HIV-infected children without previous exposure to etravirine. This could limit the efficacy of etravirine-based regimens. In addition, our results underscore the importance of taking previous history of nevirapine into account for combined antiretroviral therapy regimens that contain etravirine.

Imported congenital rubella syndrome, United States, 2017

Although transmission of rubella virus within the United States is rare, the risk for imported cases persists. We describe a rubella case in a newborn, conceived in Saudi Arabia, in Texas during 2017, highlighting the importance of active surveillance and early diagnosis of this disease.

Recent Thymus Emigrant CD4+ T Cells Predict HIV Disease Progression in Patients With Perinatally Acquired HIV

BACKGROUNDnRobust immune restoration in human immunodeficiency virus (HIV)-positive patients is dependent on thymic function. However, few studies have investigated thymic function and its correlation with disease progression over time in HIV-positive patients.nnnMETHODSnIn this longitudinal prospective study, we followed 69 HIV-positive patients who were perinatally infected. Peripheral blood mononuclear cells were stained with monoclonal anti-CD4 and anti-CD31 and recent thymic emigrants (CD4+recently emigrated from the thymus (RTE), CD4+CD31+) quantified by flow cytometry. Statistical analysis used Wilcoxon rank sum test, Kruskal-Wallis, Spearman correlation, and Kaplan-Meier estimates; Cox regression models were performed for the longitudinal analysis.nnnRESULTSnMedian age of HIV positive patients enrolled was 13 years (interquartile range [IQR], 8.6). CD4+RTE% decreased with age and was higher in females. Median CD4+RTE% was 53.5%, IQR, 22.9. CD4+RTE% was closely related to CD4+% and absolute counts but independent of viral load and CD8+CD38+%. Antiretroviral compliance as well as higher nadir CD4+% were associated with higher CD4+RTE%. Low CD4+RTE% predicted poor progression of VL and CD4+% over time.nnnCONCLUSIONSnCD4+RTE% predicts disease progression and may reflect history of disease in HIV-positive patients and adolescents. They are easy to measure in the clinical setting and may be helpful markers in guiding treatment decisions.

Incidence and predictors of antiretroviral resistance in perinatally HIV-1 infected children and adolescents.

OBJECTIVESnIndividuals with perinatally acquired HIV infection have benefited from antiretroviral therapy. However, they often have complex patterns of major resistance mutations that limit the effectiveness of available antiretroviral medications. Knowledge of incidence rates of major antiretroviral resistance mutations should provide a benchmark enabling comparisons of different HIV care delivery modalities.nnnMETHODSnWe test the hypothesis that incidence rate of major antiretroviral resistance mutations will decline with improvement in HIV care between 1998 and 2009 to NRTI, NNRTI, PI and triple class resistance in perinatally HIV infected individuals. Logistic regression is used to evaluate predictors of single and triple class resistance.nnnRESULTSnSixty-six individuals are included from a total population of 97 perinatally HIV infected individuals. The incidence rate of NRTI, NNRTI, PI and triple class resistance decreases with decreasing age in parallel with the introduction of new HIV treatment regimens. The youngest children (born 2000-2007) are free of triple class resistance. Mono-therapy associates with major resistance mutations to NRTI (OR 8.7, CI 1.5-50.9, P 0.02); NNRTI exposure associates with major resistance mutations to NNRTI (OR 24.4, CI 5.7-104.5, P 0.01) and triple class resistance (OR 10.7, CI 1.8-67.1, P 0.01). Cumulative viral load is an important predictor of PI resistance (OR 4.0, CI 1.3-12.3, P 0.02).nnnCONCLUSIONSnThere is a progressive decrease in the incidence rate of major resistance mutations to antiretroviral drugs and triple class resistance from the oldest to the youngest birth cohort; where adolescents have the highest risk of harboring resistant viruses. The incidence rate of major antiretroviral resistance mutations provides a benchmark for the comparative measurement of effectiveness of different HIV care delivery modalities.

Forkhead box protein 3+ regulatory T cells and Helios+ subset in perinatally acquired HIV

Forkhead box protein 3 (FoxP3)+ regulatory T cells (Tregs) are important not only in regulating the development of autoimmune conditions, but also in chronic infectious diseases. Given their cardinal function in suppressing immune activation, research has focused upon whether they play a detrimental role in chronic infections, particularly HIV. While the role of Tregs in HIV has been investigated intensively, it remains an unresolved topic. However, it is generally accepted that Tregs are susceptible to HIV infection and are preferentially preserved over conventional CD4+ T cells. It is unknown whether the peripheral‐induced or the thymic‐derived Tregs are more susceptible to HIV cytotoxicity. It has been recognized that Tregs can be segregated into two subsets based on Helios expression, with the vast majority being Helios+. This study examines the impact of HIV infection on total Tregs and their Helios subsets in a perinatal‐acquired HIV‐infected paediatric population. The finding indicates a selective expansion or survival of Tregs in association with CD4 depletion and increased viraemia. The Helios+ and Helios− subsets within Tregs appear to be equally affected. However, the Helios+ Tregs seem to be more preserved in patients with low CD4+u2009≤u200925% and detectable plasma HIV RNA >20 copies/ml. In this group, the frequencies of Tregs are increased, but their numbers appear insufficient to restrain immune activation. In conclusion, our findings suggest that both Helios subsets of Tregs are susceptible to HIV infection and are preferentially preserved compared to conventional CD4+ T cells.

Transverse Myelitis and Guillain-Barré Syndrome Associated with Cat-Scratch Disease, Texas, USA, 2011

We describe a case of coexisting transverse myelitis and Guillain-Barré syndrome related to infection with Bartonella henselae proteobacterium and review similar serology-proven cases. B. henselae infection might be emerging as a cause of myelitis and Guillain-Barré syndrome and should be considered as an etiologic factor in patients with such clinical presentations.