Plasma concentrations of nelfinavir and viral suppression in HIV-1 infected pregnant women

BACKGROUND: Highly active antiretroviral therapy(HAART) is used in pregnancy to suppress viral load(pVL) before delivery, reducing risk of vertical HIV-transmission. Nelfinavir(NFV) containing HAART has been highly used in pregnancy, but dosages may be inadequate due to the physiologic changes that occur. Given concerns regarding optimal viral suppression in pregnancy, drug toxicity and resistance development, NFV levels need to be evaluated in this population to guide dosing recommendations. METHODS: As part of a prospective cohort study maternal blood was collected at 18-28wks, 32-37wks and at delivery. Times of last medication dose and blood sampling were recorded and drug levels were measured using HPLC MS-MS. NFV concentration-ratios(NFV-CRs) were calculated by dividing individual levels by a time-adjusted population value. Plasma NFV concentrations and NFV-CRs were compared across gestational age and correlated to variables of interest. Rate and maintenance of viral suppression were analyzed in relation to NFV concentrations and CRs. Statistical tests included ANOVA, χ2, linear regression, and Kaplan Meier estimates. RESULTS: 113 samples were collected from 32 subjects. Samples were eliminated if not in steady state (n=20); 93 samples from 32 subjects were analyzed. Mean NFV-CR at 18-28wks (1.1±0.73) and 32-37wks (0.86±0.73) were not significantly different but were both significantly higher by ANOVA (p=0.049) than the mean NFV-CR at delivery (0.44±0.50). CRs were highly variable. Of 49 antepartum samples, 49%(24) had a CR<0.90 (clinically relevant threshold). Four women reached a pVL <50 copies/mL by 34wks but had a detectable pVL at delivery. One woman never reached an undetectable pVL in pregnancy. Minimum and mean NFV-CRs in these 5 women were not significantly different than those who achieved and maintained virologic suppression. Vertical HIV transmission rate was 0%. CONCLUSIONS: There were no HIV transmissions but 16% (5/32) of women were inadequately suppressed at delivery, which is of concern. Factors associated with inadequate suppression and NFV-CRs need to be explored in conjunction with patient/physician reported adherence and viral resistance profiles. Extreme variability in CRs may limit the potential usefulness of random timed drug levels in all pregnant women.Medicine, Faculty ofObstetrics and Gynaecology, Department ofGraduat

Investigation of Factors Associated with Spontaneous Preterm Birth in Pregnant Women Living with HIV

Objective: To investigate factors contributing to preterm birth (PTB), including cART use and clinical and social determinants of health, in women living with HIV (WLWH) from British Columbia, Canada. Design: Retrospective observational cohort. Methods: We investigated the effect of cART use and other clinical and demographic factors on spontaneous PTB (sPTB) rates (<37 weeks gestational age) among 631 singleton pregnancies between 1997-2018. Exposure to cART was modelled in comparison to no exposure, exposure in the first trimester, and between regimens. Differences in sPTB risk were estimated using time52 dependent Cox’s proportional hazards models. Results: Overall, the sPTB rate was 16%. Cumulative cART use was associated with lower risk of PTB (Wald test p=0.02; HR=0.98, 95% CI=0.96-0.99) and specific cART regimens were not associated with increased risk of sPTB. Exposure in the first trimester was not associated with sPTB and for each week of cART exposure, the risk of sPTB decreased by 2%. In a multivariable model, HIV viral load and substance use remained associated with risk of sPTB, but not cART exposure. Conclusions: The sPTB rate among pregnant WLWH was more than three times higher than in the general population. However, sPTB was not related specifically to use of cART; in fact, cART appeared to reduce the risk of sPTB. Uncontrolled HIV replication and substance use were associated with increased risk of sPTB among pregnant WLWH. This emphasizes the important role of prenatal care, access to cART, and smoking cessation and harm reduction to reduce the risk of sPTB in WLWH.Medicine, Faculty ofOther UBCObstetrics and Gynaecology, Department ofPediatrics, Department ofReviewedFacultyResearcherGraduat

Evidence of Subclinical mtDNA Alterations in HIV-Infected Pregnant Women Receiving Combination Antiretroviral Therapy Compared to HIV-Negative Pregnant Women.

Combination antiretroviral therapy (cART) can effectively prevent vertical transmission of HIV but there is potential risk of adverse maternal, foetal or infant effects. Specifically, the effect of cART use during pregnancy on mitochondrial DNA (mtDNA) content in HIV-positive (HIV+) women is unclear. We sought to characterize subclinical alterations in peripheral blood mtDNA levels in cART-treated HIV+ women during pregnancy and the postpartum period.This prospective longitudinal observational cohort study enrolled both HIV+ and HIV-negative (HIV-) pregnant women. Clinical data and blood samples were collected at three time points in pregnancy (13-<23 weeks, 23-<30 weeks, 30-40 weeks), and at delivery and six weeks post-partum in HIV+ women. Peripheral blood mtDNA to nuclear DNA (nDNA) ratio was measured by qPCR.Over a four year period, 63 HIV+ and 42 HIV- women were enrolled. HIV+ women showed significantly lower mtDNA/nDNA ratios compared to HIV- women during pregnancy (p = 0.003), after controlling for platelet count and repeated measurements using a multivariable mixed-effects model. Ethnicity, gestational age (GA) and substance use were also significantly associated with mtDNA/nDNA ratio (p≤0.02). Among HIV+ women, higher CD4 nadir was associated with higher mtDNA/nDNA ratios (p<0.0001), and these ratio were significantly lower during pregnancy compared to the postpartum period (p<0.0001).In the context of this study, it was not possible to distinguish between mtDNA effects related to HIV infection versus cART therapy. Nevertheless, while mtDNA levels were relatively stable over time in both groups during pregnancy, they were significantly lower in HIV+ women compared to HIV- women. Although no immediate clinical impact was observed on maternal or infant health, lower maternal mtDNA levels may exert long-term effects on women and children and remain a concern. Improved knowledge of such subclinical alterations is another step toward optimizing the safety and efficacy of cART regimens during pregnancy

Means, model estimates, and Chi-squared results for the mixed-effects modelling of mtDNA levels within the 63 HIV+ pregnant women.

<p>^a Means (± SEM) are reported for the raw data without correction for covariates.</p><p>^b Estimated effects after taking covariates into account.</p><p>^d LRT = likelihood-ratio test statistic</p><p>SEM, Standard error on the mean</p><p>df, degrees of freedom</p><p>Means, model estimates, and Chi-squared results for the mixed-effects modelling of mtDNA levels within the 63 HIV+ pregnant women.</p

HIV-specific clinical characteristics of HIV+ cohort (n = 63).

<p>HIV-specific clinical characteristics of HIV+ cohort (n = 63).</p

Significant associations between mtDNA/nDNA ratio and variables of interest for both HIV- and HIV+ cohorts (<i>N</i> = 105).

<p>(A) Ethnicity, (B) GA at visit (weeks) and (C) Illicit drug use. In A and C, the horizontal line in the boxplots indicates the median value, boxes represent the interquartile range, whiskers indicate 1.5 times the interquartile range, while points indicate outliers. In B, the best-fit line from the mixed-effects model controlling for platelets and other significant variables is shown. All samples were collected during pregnancy.</p

Means, model estimates, and log-likelihood ratio test Chi-squared results for the mixed-effects modelling of mtDNA levels in all HIV+ and HIV- pregnant women (n = 105).

<p>^a Means (± SEM) are reported for the raw data without correction for covariates.</p><p>^b Estimated effects after taking covariates into account.</p><p>^c The modelling did not differentiate between women using 2 or more illicit drugs during pregnancy and women only taking one illicit drug.</p><p>^d LRT = likelihood-ratio test statistic</p><p>SEM, Standard error on the mean</p><p>df, degrees of freedom</p><p>GA, gestational age</p><p>Means, model estimates, and log-likelihood ratio test Chi-squared results for the mixed-effects modelling of mtDNA levels in all HIV+ and HIV- pregnant women (n = 105).</p

Perinatal and neonatal outcomes for HIV+ (n = 63) and HIV- (n = 42) maternal infant pairs.

<p>^a One infant born to an HIV- mother was stillborn.</p><p>^b Two HIV- control women were considered at high risk of contracting HIV due to drug use and unprotected intercourse with partners with unknown HIV status; therefore, infants were treated with zidovudine (ZDV) and nevirapine (NVP) as per standard of care.</p><p>^c Maternal HIV+ group: pulmonary artery stenosis (n = 2), pyloric stenosis (n = 1), hydronephrosis (n = 1); Maternal HIV- group: hydronephrosis (n = 1).</p><p>^d Maternal HIV+ group: mild respiratory distress (n = 1), respiratory syncytial virus (RSV) infection (n = 1), seizures (n = 1), sepsis (n = 1), apnoea of prematurity (n = 1), pneumonia (n = 1); Maternal HIV- group: mild respiratory distress (n = 1), neonatal intensive care unit for >24 hours (n = 1), hyperbilirubinaemia (n = 1).</p><p>Continuous variables were tested for differences between the groups using t-tests; Apgar scores were compared using a Wilcoxon rank-sum test; categorical variables were compared using Chi Squared tests or Fisher exact tests where appropriate.</p><p>SD, standard deviation</p><p>Perinatal and neonatal outcomes for HIV+ (n = 63) and HIV- (n = 42) maternal infant pairs.</p

Temporal variation in mtDNA/nDNA ratio during pregnancy, at delivery and postpartum for the HIV+ cohort.

<p>A) mtDNA/nDNA ratio in HIV- women (n = 42), HIV+ women who initiated cART prior to conception (n = 17) and continued throughout pregnancy, and HIV+ women who initiated cART during pregnancy (n = 46) at each sample time point (13–22 weeks, 23–30 weeks, 31–40 weeks, delivery, 6 weeks postpartum); mtDNA/ nDNA ratio among HIV+ women (n = 63) for the significant variables of (B) time of visit (13–22 weeks, 23–30 weeks, 31–40 weeks, delivery, 6 weeks postpartum), where the horizontal line in the boxplots indicates the median value, boxes represent the interquartile range, whiskers indicate 1.5 times the interquartile range, while points indicate outliers; (C) CD4 nadir, where the best-fit line from the mixed-effects model is shown.</p