Early infant HIV diagnosis and entry to HIV care cascade in Thailand: an observational study.

BACKGROUND: Early infant diagnosis of HIV is crucial for timely initiation of antiretroviral therapy (ART) in infected children who are at high risk of mortality. Early infant diagnosis with dried blood spot testing was provided by the National AIDS Programme in Thailand from 2007. We report ART initiation and vital status in children with HIV after 7 years of rollout in Thailand. METHODS: Dried blood spot samples were collected from HIV-exposed children in hospitals in Thailand and mailed to the Faculty of Associated Medical Sciences, Chiang Mai University, where HIV DNA was assessed with real-time PCR to establish HIV infection. We linked data from children with an HIV infection to the National AIDS Programme database to ascertain ART and vital status. FINDINGS: Between April 5, 2007, and Oct 1, 2014, 16 046 dried blood spot samples were sent from 8859 children in 364 hospitals in Thailand. Median age at first dried blood spot test was 2·1 (IQR 1·8-2·5) months. Of 7174 (81%) children with two or more samples, 223 (3%) were HIV positive (including five unconfirmed). Of 1685 (19%) children with one sample, 70 (4%) were unconfirmed positive. Of 293 (3%) children who were HIV positive, 220 (75%) registered for HIV care and 170 (58%) initiated ART. Median age at ART initiation decreased from 14·2 months (IQR 10·2-25·6) in 2007 to 6·1 months (4·2-9·2) in 2013, and the number of children initiating ART aged younger than 1 year increased from five (33%) of 15 children initiating ART in 2007 to ten (83%) of 12 initiating ART in 2013. 15 (9%) of 170 children who initiated ART died and 16 (32%) of 50 who had no ART record died. INTERPRETATION: Early infant diagnosis with dried blood spot testing had high uptake in primary care settings. Further improvement of linkage to HIV care is needed to ensure timely treatment of all children with an HIV infection. FUNDING: None.

Uptake of early infant diagnosis in Thailand's national program for preventing mother-to-child HIV transmission and linkage to care, 2008-2011.

INTRODUCTION: Early infant diagnosis (EID) has been a component of Thailand's prevention of mother-to-child HIV transmission (PMTCT) programme since 2007. This study assessed the uptake, EID coverage, proportion of HIV-exposed infants receiving a definitive HIV diagnosis, mother-to-child transmission (MTCT) rates and linkage to HIV care and treatment. METHODS: Infant polymerase chain reaction (PCR) testing data from the National AIDS Program database were analyzed. EID coverage was calculated as the percentage of number of HIV-exposed infants receiving ≥ 1 HIV PCR test divided by the number of HIV-exposed infants estimated from HIV prevalence and live-birth registry data. Definitive HIV diagnosis was defined as having two concordant PCR results. MTCT rates were calculated based on infants tested with PCR and applied as a best-case scenario, and a sensitivity analysis was used to adjust these rates in average and worst scenarios. We defined linkage to HIV care as infants with at least one PCR-positive test who were registered with Thailand's National AIDS Program. Chi-squared tests for linear trend were used to analyze changes in programme coverage. RESULTS: For 2008 to 2011, the average EID coverage rate increased from 54 to 76% (p < 0.001), with 65% coverage (13,761/21,099) overall. The number of hospitals submitting EID samples increased from 458 to 645, and the percentage of community hospitals submitting samples increased from 75 to 78% (p = 0.044). A definitive HIV diagnosis was made for 10,854 (79%) infants during this period. The adjusted MTCT rates had significantly decreasing trends in all scenarios. Overall, an estimated 53% (429/804) of HIV-infected infants were identified through the EID programme, and 80% (341/429) of infants testing positive were linked to care. The overall rate of antiretroviral treatment (ART) initiation within one year of age was 37% (157/429), with an increasing trend from 28 to 52% (p < 0.001). CONCLUSIONS: EID coverage increased and MTCT rates decreased during 2008 to 2011; however, about half of HIV-infected infants still did not receive EID. Most HIV-infected infants were linked to care but less than half initiated ART within one year of age. Active follow-up of HIV-exposed infants to increase early detection of HIV infection and early initiation of ART should be more widely implemented.

Cost-effectiveness of early infant HIV diagnosis of HIV-exposed infants and immediate antiretroviral therapy in HIV-infected children under 24 months in Thailand.

BACKGROUND: HIV-infected infants have high risk of death in the first two years of life if untreated. WHO guidelines recommend early infant HIV diagnosis (EID) of all HIV-exposed infants and immediate antiretroviral therapy (ART) in HIV-infected children under 24-months. We assessed the cost-effectiveness of this strategy in HIV-exposed non-breastfed children in Thailand. METHODS: A decision analytic model of HIV diagnosis and disease progression compared: EID using DNA PCR with immediate ART (Early-Early); or EID with deferred ART based on immune/clinical criteria (Early-Late); vs. clinical/serology based diagnosis and deferred ART (Reference). The model was populated with survival and cost data from a Thai observational cohort and the literature. Incremental cost-effectiveness ratio per life-year gained (LYG) was compared against the Reference strategy. Costs and outcomes were discounted at 3%. RESULTS: Mean discounted life expectancy of HIV-infected children increased from 13.3 years in the Reference strategy to 14.3 in the Early-Late and 17.8 years in Early-Early strategies. The mean discounted lifetime cost was $17,335, $22,583 and $29,108, respectively. The cost-effectiveness ratio of Early-Late and Early-Early strategies was $5,149 and $2,615 per LYG, respectively as compared to the Reference strategy. The Early-Early strategy was most cost-effective at approximately half the domestic product per capita per LYG ($4,420 in Thailand 2011). The results were robust in deterministic and probabilistic sensitivity analyses including varying perinatal transmission rates. CONCLUSION: In Thailand, EID and immediate ART would lead to major survival benefits and is cost- effective. These findings strongly support the adoption of WHO recommendations as routine care.

The diagnostic value of intraocular fluid analysis by polymerase chain reaction in Thai patients with uveitis.

Uveitis is a major cause of severe visual impairment throughout the world and can be initiated by various infectious and non-infectious causes. Early recognition of specific infections is important as the treatment with antimicrobial agents might stop the progression or even cure the eye disease. To determine the infectious causes of uveitis in Thailand, intraocular fluid samples of 100 HIV-negative patients and 47 HIV-positive patients with uveitis were examined using real-time PCR analysis for herpes simplex virus, varicella zoster virus, cytomegalovirus and Toxoplasma gondii. Positive PCR results were found in 33/100 (33%) HIV-negative patients and in 33/47 (70%) HIV-positive patients with uveitis. In Thailand, cytomegalovirus was identified as the most frequent cause of infectious uveitis in both HIV-negative and HIV-positive patients (49 and 91%, respectively). PCR analysis of intraocular samples in uveitis was a valuable diagnostic assay. The pattern of uveitis observed in the Far East differs from that found in the West.

Intraocular and plasma HIV-1 RNA loads and HIV uveitis.

OBJECTIVE: The objective of this study was to analyze human immunodeficiency virus (HIV) dynamics across the blood-retinal barrier and to determine whether the high levels of HIV in the eye are associated with any ocular disorders in HIV-infected patients. DESIGN: This study included a prospective case series of 40 HIV-positive patients with uveitis. INTERVENTION: Clinical and laboratory examinations included plasma and intraocular HIV-1 RNA loads as well as the clinical manifestations of uveitis. RESULTS: Intraocular HIV-1 RNA was detected in 32% (13/40) of HIV-positive patients with uveitis. Intraocular HIV-1 RNA loads were associated with high HIV-1 RNA plasma loads (P < 0.001) and not being on HAART therapy (P = 0.005). In addition, detectable intraocular HIV-1 RNA levels were higher in patients with the absence of retinal lesions (P = 0.008). In three patients, the HIV load in the eye largely exceeded that of plasma. These three patients had all bilateral anterior uveitis and/or vitritis without retinal lesions and exhibited no evidence of other intraocular infectious agents causing uveitis than HIV itself. CONCLUSION: The eye can form a sanctuary where HIV might replicate and cause an inflammatory reaction.

Unmasking tuberculosis-associated immune reconstitution inflammatory syndrome in HIV-1 infection after antiretroviral therapy.

The exaggerated immune response to the subclinical opportunistic microorganisms or their antigens can be found in HIV-1 infected patients after receiving antiretroviral (ARV) therapy. We report a case of unmasking tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) in the HIV-1 infected patient who had no previous history of mycobacterial infection. She had tuberculosis of intestines, peritoneum and mesenteric glands within 2 months of ARV. However, her sputum acid-fast bacilli stain, sputum, blood and cervical lymph node aspiration cultures for mycobacterium were negative. Her CD4 cell count increased of from 46 cells/microL at baseline before receiving ARV to 155 cells/microL at month 6 of ARV. In addition, her plasma pro-inflammatory (IFN-gamma and TNF-alpha) and anti-inflammatory (IL-10) cytokine measurement was supported the occurrence of immune restoration reaction. Therefore, the changing in these cytokine profiles may be an important marker of developing unmasking TB-IRIS.

Evolution of hematological parameters in HIV-1-infected patients with and without thalassemia carriages during highly active antiretroviral therapy.

OBJECTIVES: To assess the effects of highly active antiretroviral therapy (HAART) on hematological parameters in HIV-1-infected patients with and without thalassemia carriages. METHODS: Prospective study was conducted in HIV-1-infected Thai patients receiving HAART. Their hematological parameters were measured at baseline and during follow-up of 1 year. beta-thalassemia and hemoglobin-E trait were diagnosed using HPLC. PCR-genotyping techniques were used to investigate alpha-thalassemia-1 Southeast Asian type deletion and beta-thalassemia mutation. The changes of hematological parameters were compared according to thalassemia carriage. RESULTS: During follow-up, increased levels of CD4 counts, hemoglobin, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were observed in the groups of patients with and without thalassemia. The changes in mean hemoglobin level, MCV, and MCH in both groups appeared parallel, with consistently lower levels in patients with thalassemia. At Months 6 and 12, mean MCV of patients with thalassemia was shifted from microcytic levels (<80 fL) to normocytic levels (80-100 fL) while their mean MCH was increased to normal levels (27-31 pg). CONCLUSION: Although HAART altered hematological parameters such as MCV and MCH, it did not induce worsening anaemia, especially in patients with thalassemia carriages. However, the increased levels of MCV and MCH crucially affect the thalassemia screening.

Increased Hb A2 values in an HIV-1-infected patient receiving antiretroviral drugs: a pitfall for thalassemia antenatal diagnosis.

We report a human immunodeficiency virus-1 (HIV-1)-infected couple, where the woman in the 11th week of gestation, carried a Hb E trait. She and her spouse were referred to the hemoglobinopathy counselors. Her spouse's blood was subsequently tested and showed an increased Hb A(2) value. However, his red cell indices and osmotic fragility test were different from those found in beta-thalassemia (beta-thal) carriers. The beta-thal genes were investigated further and no mutations were observed. Therefore, it is unlikely that he is a beta-thal carrier and the increased Hb A(2) value is a result of receiving antiretroviral drugs. As antenatal thalassemia screening becomes more widespread, measuring the Hb A(2) values should be taken in all HIV-1-infected couples before the initiation of antiretroviral drugs to rule out misdiagnosis of beta-thal. However, if these tests are not available, the results of the red cell indices and osmotic fragility test should be considered as they may provide great value for beta-thal investigations.

Maternal neutralizing antibodies against a CRF01_AE primary isolate are associated with a low rate of intrapartum HIV-1 transmission.

Mother-to-child transmission (MTCT) of HIV-1 provides a model for studying the role of passively acquired antibodies in preventing HIV infection. We determined the titers of neutralizing antibodies (NAbs) against six primary isolates of clades B and CRF01_AE in sera from 45 transmitting and 45 nontransmitting mothers matched for the main independent factors associated with MTCT in Thailand. A lower risk of MTCT, particularly for intrapartum transmission, was associated only with higher NAb titers against the CRF01_AE strain, MBA. The envelope glycoprotein of this strain showed an unusually long V2 domain of 63 amino acids, encoding six potential N-linked glycosylation sites. We provided experimental data indicating that the extended V2 domain contributed to the higher level of resistance to neutralization by mothers' sera in this strain. Taken together the data suggest that some primary isolates with specific properties may be useful indicators for identifying protective antibodies.

Infectious uveitis in Thailand: serologic analyses and clinical features.

PURPOSE: To determine the seroprevalence of various infectious agents in Thai patients with uveitis. METHODS: Prospective study of 101 consecutive patients with uveitis, 100 HIV-infected retinitis patients, and 100 nonuveitis controls. RESULTS: Antibodies against T. gondii were detected in 31/101 non-HIV patients, mostly with posterior uveitis and focal retinitis, and were significantly higher than in other groups examined. Antibodies for T. pallidum and Leptospira were observed more frequently in patients with HIV-infected retinitis. Active tuberculosis in non-HIV patients was not found. CONCLUSIONS: Seroprevalence of T. gondii antibodies in patients with non-HIV posterior uveitis was higher than in nonuveitis controls and HIV patients with retinitis.

Higher placental anti-inflammatory IL-10 cytokine expression in HIV-1 infected women receiving longer zidovudine prophylaxis associated with nevirapine.

Placental cytokine balance may be critical for the control of mother-to-child transmission (MTCT) of HIV. We assessed whether the type and duration of antiretrovirals used for prevention of HIV-1-MTCT modified the inflammatory cytokine profile. We investigated the levels of cytokine expression in the placentas of 61 HIV-1-infected women who received zidovudine (ZDV) plus single dose nevirapine (SD-NVP) or ZDV only for prevention of MTCT. Placentas of 38 HIV-1-uninfected women were included as controls. All placentas were obtained after vaginal delivery. Levels of mRNA and cytokine expression were quantified using real-time PCR and ELISA, respectively, in placental explants and 24-hour culture supernatants and analyzed in relation to the women's characteristics and the type and duration of antiretroviral prophylaxis. HIV-1-infected and uninfected women did not show any differences in the expression of placental cytokine secretion except for a trend toward lower TNF-alpha mRNA levels in HIV-1-infected women. Within the HIV-1-infected group, women who were exposed to a long duration of ZDV (>72 days) or received SD-NVP less than 5h prior to delivery, more frequently expressed detectable levels of IL-10 in their placentas (32% versus 7% (p = 0.01) and 32% versus 5% (p = 0.02), respectively). No infant was found to be HIV-1-infected. Our results showed a normalization of the placental cytokine balance in HIV-1-infected women receiving antiretroviral prophylaxis. Furthermore, the type and duration of antiretroviral prophylaxis have an impact on the placental anti-inflammatory IL-10 expression level, which may contribute to controlling HIV replication at the placental level, thus reducing MTCT of HIV-1.

Development of TaqMan real-time polymerase chain reaction for the detection and identification of Penicillium marneffei.

Penicillium marneffei is a dimorphic fungus, which is endemic in Southeast Asia and responsible for emerging opportunistic infections. Diagnosis of penicilliosis may be difficult when few yeast cells are present, while a gold standard diagnosis technique requires long-term culture. In order to provide a more rapid and accurate diagnosis, we developed a TaqMan real-time PCR to detect and identify P. marneffei DNA coding for 5.8S rRNA in purified yeast DNA and clinical samples. All P. marneffei DNA preparations could be detected using specific primers and TaqMan probe. The assay has a sensitivity to detect at least 10 yeast cells in seeded blood. Moreover, it can detect P. marneffei DNA in peripheral blood samples and blood-culture bottles. Therefore, the real-time PCR assay may represent a potential tool for early diagnosis of penicilliosis marneffei.

Early HIV-1 diagnosis using in-house real-time PCR amplification on dried blood spots for infants in remote and resource-limited settings.

BACKGROUND: In resource-limited settings, most perinatally HIV-1-infected infants do not receive timely antiretroviral therapy because early HIV-1 diagnosis is not available or affordable. OBJECTIVE: To assess the performance of a low-cost in-house real-time polymerase chain reaction (PCR) assay to detect HIV-1 DNA in infant dried blood spots (DBS). METHODS: One thousand three hundred nineteen DBS collected throughout Thailand from non-breast-fed infants born to HIV-1-infected mothers were shipped at room temperature to a central laboratory.In-house real-time DNA PCR results were compared with Roche Amplicor HIV-1 DNA test (Version 1.5) results. In addition, we verified the Roche test performance on DBS sampled from 1218 other infants using as reference HIV serology result at 18 months of age. RESULTS: Real-time DNA PCR and Roche DNA PCR results were 100% concordant. Compared with HIV serology results, the Roche test sensitivity was 98.6% (95% confidence interval: 92.6% to 100.0%) and its specificity at 4 months of age was 99.7% (95% confidence interval: 99.2% to 99.9%). CONCLUSIONS: In-house real-time PCR performed as well as the Roche test in detecting HIV-1 DNA on DBS in Thailand. Combined use of DBS and real-time PCR assays is a reliable and affordable tool to expand access to early HIV-1 diagnosis in remote and resource-limited settings, enabling timely treatment for HIV-1-infected infants.

Characteristics of HIV type 1 (HIV-1) glycoprotein 120 env sequences in mother-infant pairs infected with HIV-1 subtype CRF01_AE.

We analyzed the characteristics of the envelope genes of human immunodeficiency virus type 1 in 17 mother-infant pairs infected with variants of the CRF01_AE clade. A total of 353 sequences covering almost the entire glycoprotein (gp) 120 region were available for analysis. We found that, even if the virus population in the mother was complex, only viruses of a restricted subset were transmitted to her infant, independently of whether transmission occurred in utero or during the intrapartum period. We did not find that shorter gp120 regions or fewer potential N-glycosylation sites (PNGS) were characteristic of viruses transmitted from mother to infant. However, our data suggest that a limited number of PNGS that seem to be conserved in all variants in infants but are not uniformly present in variants in mothers may confer an advantage for transmission of the virus, thereby highlighting the potentially important role of the "glycan shield." This finding was particularly significant for the PNGS at positions N301 and N384.

Analysis of real-time SYBR-polymerase chain reaction cycle threshold for diagnosis of the alpha-thalassemia-1 Southeast Asian type deletion: application to carrier screening and prenatal diagnosis of Hb Bart's hydrops fetalis.

Without gel electrophoresis and specific probes, the two tubes real-time SYBR-polymerase chain reaction (SYBR-PCR) was setup by using different primer sets: P1/P2 for the detection of wild type alpha-globin gene alleles and P1/P3 for detection of the allele bearing the Southeast Asian (SEA) type (--SEA) deletion. Analyses of the cycle threshold (CT) values obtained by each primer set together with a delta-cycle threshold (DeltaCT) and CT ratio, showed that lower CT values generated by primer sets P1/P2 and P1/P3 were observed in normal and Hb Bart's hydrops fetalis subjects, respectively. In heterozygous subjects the CT values generated by both sets of primers were similar to each other. There was no overlapping of DeltaCT and CT ratio between normal, heterozygous and Hb Bart's hydrops fetalis subjects. Therefore, the two tubes real-time SYBR-PCR could represent a rapid, cost effective, high-throughput assay for screening of carriers and prenatal diagnosis of alpha-thalassemia-1 (alpha-thal-1) with the SEA type (--SEA) deletion.

A study of seven rule-based algorithms for the interpretation of HIV-1 genotypic resistance data in Thailand.

Since the free therapy program was started by the Thai government, the number of patients infected by HIV-1 with access to antiretroviral drugs has increased. The selection of effective interpretation algorithms for antiretroviral drug resistance has become even more important for clinical management. In this retrospective study, the level of agreement was evaluated in 721 antiretroviral-therapy failing HIV-1 subjects. Regarding genetic diversity, about 89% was recognized as non-B variants (CRF01_AE). The level of complete concordant interpretation score in all seven algorithms was recognized in non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) (67%), but not in nucleoside reverse transcriptase inhibitors (NRTIs) (52%). Over 10% of the major discordance score with TRUGENE was revealed in didanosine (Agence Nationale de Recherches sur le SIDA[ANRS]; Detroit Medical Centre [DMC]), abacavir (ANRS; Centre Hospitalier de Luxembourg [CHL]), and also with delavirdine, indinavir and amprenavir (Grupo de Aconselhamento Virológico [GAV]). A good to excellent agreement range of kappa scores was detected for most antiretroviral drugs. However, poor agreement with the TRUGENE system (k<0.40) was seen in the ANRS system with didanosine, abacavir and lopinavir; GAV system in indinavir and amprenavir; and DMC system in ritonavir. These might be an option for resource limited countries when selecting the use of a low cost or free algorithm interpretation, which has excellent agreement as the U.S. Food and Drug Administration (FDA)-approved TRUGENE commercial system.

Antimutagenicity and DT-diaphorase inducing activity of Gynostemma pentaphyllum Makino extract.

The hot water extract of the herbal tea, Gynostemma pentaphyllum Makino, was not found to be mutagenic in Salmonella mutation assay with or without metabolic activation. However, the extract had both DT-diaphorase inducing activity in the murine hepatoma (Hepa1c1c7) cell line and antimutagenic properties towards chemical-induced mutation in Salmonella typhimurium strains TA98 and TA100. Mutagenicity of aflatoxin B1 (AFB1), 2-amino-6-methyldipyrido [1, 2-a: 3', 2', 3-d] imidazole (Glu-P-1), 2-aminodipyrido [1, 2-a: 3', 2', 3-d] imidazole (GIu-P-2), 2-amino-1, 4-dimethyl-5H-pyrido [4, 3-b] indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido [4, 3-b] indole (Trp-P-2), 2-amino-3-methylimidazo [4, 5-f] quinoline (IQ) and Benzo [a] pyrene (B[a]P) was inhibited by the extract of Gynostemma pentaphyllum Makino in a dose-dependent manner, but no effect was found on the mutagenic activity of 2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide (AF-2). However, the extract enhanced the mutagenicity induced by 2-aminoanthracene (2AA), and N-methyl-N-nitro-N-nitrosoguanidine (MNNG).

Efficacy and safety of zidovudine and zalcitabine combined with a combination of herbs in the treatment of HIV-infected Thai patients.

A randomized double blind placebo controlled trial to determine the efficacy and safety of combined-herbs (SH) given with zidovudine (ZDV) and zalcitabine (ddC) for the treatment of HIV infection in Thai adults was conducted in 3 hospitals in northern Thailand during 2002 to 2003. The eligible subjects were HIV-infected Thai adults who had never received anti-retrovirals, had a Karnofski Performance Score (KPS) of > or = 70, and had no opportunistic infections. The subjects were randomized to receive either a combination of ZDV 200 mg three times per day, ddC 0.75 mg three times per day, and SH 2.5 g three times per day or a combination of ZDV 200 mg three times per day, ddC 0.75 mg three times per day, and placebo 2.5 g three times per day for 24 weeks. The main outcome measures were HIV-RNA, CD4 cells, and blood chemistry profiles prior to the treatment and then every 4 weeks for 24 weeks. The baseline characteristics of 60 evaluable subjects, 40 in the SH group and 20 in the placebo group, were not significantly different. HIV RNA at week 4 and thereafter was significantly decreased from the baseline value in both groups (p<0.001). However, the decline in HIV RNA in the SH group was significantly more than that in the placebo group. The CD4 cells in the SH group at week 12 and thereafter were significantly increased from the baseline value. Serious adverse events in the two groups were not observed. It is concluded that an addition of SH herbs to two nucleoside reverse transcriptase inhibitors has greater antiviral activity than antiretrovirals only. The SH herbs may be an alternative for the third anti-retroviral agent in the triple drug regimen for the treatment of HIV infected patients in countries with limited resources.

Intrapartum exposure to nevirapine and subsequent maternal responses to nevirapine-based antiretroviral therapy.

BACKGROUND: A single intrapartum dose of nevirapine for the prevention of mother-to-child transmission of human immunodeficiency virus (HIV) leads to the selection of resistance mutations. Whether there are clinically significant consequences in mothers who are subsequently treated with a nevirapine-containing regimen is unknown. METHODS: We randomly assigned 1844 women in Thailand who received zidovudine during the third trimester of pregnancy to receive intrapartum nevirapine or placebo. In the postpartum period, 269 of the women with a CD4 count below 250 cells per cubic millimeter began a nevirapine-containing antiretroviral regimen. Plasma samples were obtained 10 days post partum and analyzed for resistance mutations. Plasma HIV type 1 (HIV-1) RNA was measured before the initiation of therapy and three and six months thereafter. RESULTS: After six months of therapy, the HIV-1 RNA level was less than 50 copies per milliliter in 49 percent of the women who had received intrapartum nevirapine, as compared with 68 percent of the women who had not received intrapartum nevirapine (P=0.03). Resistance mutations to nonnucleoside reverse-transcriptase inhibitors were detectable in blood samples obtained 10 days post partum from 32 percent of the women who had received intrapartum nevirapine; the most frequent mutations were K103N, G190A, and Y181C. Among the women who had received intrapartum nevirapine, viral suppression was achieved at six months in 38 percent of those with resistance mutations and 52 percent of those without resistance mutations (P=0.08). An HIV-1 RNA level at or above the median of 4.53 log10 copies per milliliter before therapy and intrapartum exposure to nevirapine were independently associated with virologic failure. After six months of therapy, there was no significant difference between groups in the CD4 count (P=0.65). CONCLUSIONS: Women who received intrapartum nevirapine were less likely to have virologic suppression after six months of postpartum treatment with a nevirapine-containing regimen. Our data suggest the need for strategies to maximize the benefits of both antiretroviral prophylaxis against mother-to-child transmission of HIV and antiretroviral therapy for mothers.

Modulation of P-glycoprotein expression and function by curcumin in multidrug-resistant human KB cells.

Multidrug resistance (MDR) is a phenomenon that is often associated with decreased intracellular drug accumulation in the tumor cells of a patient, resulting from enhanced drug efflux. It is often related to the overexpression of P-glycoprotein (Pgp) on the surface of tumor cells, thereby reducing drug cytotoxicity. In this study, curcumin was tested for its potential ability to modulate the expression and function of Pgp in the multidrug-resistant human cervical carcinoma cell line KB-V1. Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) showed that treatment with 1, 5, and 10 microM curcumin for up to 72hr was able to significantly lower Pgp expression in KB-V1 cells. Curcumin (1-10 microM) decreased Pgp expression in a concentration-dependent manner and was also found to have the same effect on MDR1 mRNA levels. The effect of curcumin on Pgp function was demonstrated by rhodamine 123 (Rh123) accumulation and efflux in Pgp-expressing KB-V1 cells. Curcumin increased Rh123 accumulation in a concentration-dependent manner (1-55 microM) and inhibited the efflux of Rh123 from these cells, but did not affect the efflux of Rh123 from the wild-type drug-sensitive KB-3-1 cells. Treatment of drug-resistant KB-V1 cells with curcumin increased their sensitivity to vinblastine, which was consistent with an increased intracellular accumulation of Rh123. In addition, curcumin inhibited verapamil-stimulated ATPase activity and the photoaffinity labeling of Pgp with the prazosin analog [125I]iodoarylazidoprazosin in a concentration-dependent manner, demonstrating that curcumin interacts directly with the transporter. Thus, curcumin seems to be able to modulate the in vitro expression and function of Pgp in multidrug-resistant human KB-V1 cells. In summary, this study describes the duel modulation of MDR1 expression and Pgp function by the phytochemical curcumin, which may be an attractive new agent for the chemosensitization of cancer cells.