Browsing by Author "Gausi, Kamunkhwala"
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- ItemEffects of pregnancy and isoniazid preventive therapy on mycobacterium tuberculosis interferon gamma response assays in women with HIV(Oxford University Press, 2020-07) Weinberg, Adriana; Aaron, Lisa; Montepiedra, Grace; Sterling, Timothy R.; Browning, Renee; Mmbaga, Blandina; Vhembo, Tichaona; Naik, Shilpa; Kabugho, Enid; Masheto, Gaerolwe; Pahwa, Savita; Mathad, Jyoti S.; LaCourse, Sylvia M.; McCarthy, Katie; Bradford, Sarah; Theron, Gerhard; Costello, Diane; Zimmer, Bonnie; Pierre, Marie F.; Gausi, Kamunkhwala; Denti, Paolo; Haas, David W.; Gupta, AmitaBackground Pregnancy is accompanied by immune suppression. We hypothesized that Mycobacterium tuberculosis-specific inflammatory responses used to identify latent tuberculosis infection (LTBI) lose positivity during pregnancy. We also hypothesized that isoniazid preventive therapy (IPT) may revert LTBI diagnoses because of its sterilizing activity. Methods 944 women with human immunodeficiency virus infection (HIV) participating in a randomized, double-blind, placebo-controlled study comparing 28 weeks of IPT antepartum versus postpartum, were tested by QuantiFERON-gold-in-tube (QGIT) antepartum and by QGIT and tuberculin skin test (TST) at delivery and postpartum. Serial QGIT positivity was assessed by logistic regression using generalized estimating equations. Results From entry to delivery, 68 (24%) of 284 QGIT-positive women reverted to QGIT-negative or indeterminate. Of these, 42 (62%) recovered QGIT positivity postpartum. The loss of QGIT positivity during pregnancy was explained by decreased interferon gamma (IFNγ) production in response to TB antigen and/or mitogen. At delivery, LTBI was identified by QGIT in 205 women and by TST in 113 women. Corresponding numbers postpartum were 229 and 122 women. QGIT and TST kappa agreement coefficients were 0.4 and 0.5, respectively. Among QGIT-positive women antepartum or at delivery, 34 (12%) reverted to QGIT-negative after IPT. There were no differences between women who initiated IPT antepartum or postpartum. Conclusions Decreased IFNγ responses in pregnancy reduced QGIT positivity, suggesting that this test cannot reliably rule out LTBI during pregnancy. TST was less affected by pregnancy, but had lower positivity compared to QGIT at all time points. IPT was associated with loss of QGIT positivity, the potential clinical consequences of which need to be investigated.
- ItemPharmacokinetics and Drug-Drug Interactions of Isoniazid and Efavirenz in Pregnant Women Living With HIV in High TB Incidence Settings: Importance of Genotyping(John Wiley & Sons, Ltd, 2020) Gausi, Kamunkhwala; Wiesner, Lubbe; Norman, Jennifer; Wallis, Carole LThe World Health Organization guidelines recommend that individuals living with HIV receive ≥ 6 months of isoniazid preventive therapy, including pregnant women. Yet, plasma isoniazid exposure during pregnancy, in the antiretroviral therapy era, has not been well-described. We investigated pregnancy-induced and pharmacogenetic-associated pharmacokinetic changes and drug-drug interactions between isoniazid and efavirenz in pregnant women. Eight hundred forty-seven women received isoniazid for 28 weeks, either during pregnancy or at 12 weeks postpartum, and 786 women received efavirenz. After adjusting for NAT2 and CYP2B6 genotype and weight, pregnancy increased isoniazid and efavirenz clearance by 26% and 15%, respectively. Isoniazid decreased efavirenz clearance by 7% in CYP2B6 normal metabolizers and 13% in slow and intermediate metabolizers. Overall, both isoniazid and efavirenz exposures were reduced during pregnancy, but the main determinants of drug concentration were NAT2 and CYP2B6genotypes, which resulted in a five-fold difference for both drugs between rapid and slow metabolizers.