Pharmacokinetics of nevirapine, stavudine and lamivudine in Indian HIV-infected children receiving generic fixed dose combinations

OBJECTIVE

To determine the trough and two hour plasma levels of nevirapine, stavudine, and lamivudine when administered in fixed dose combinations (FDC).

DESIGN

Cross sectional.

SETTING

Tertiary care hospital in Northern India.

PARTICIPANTS

79 HIV-infected children receiving antiretroviral therapy with FDCs for more than month.

INTERVENTION

Two-point sampling (0 and 2 hours after the morning dose).

OUTCOME MEASURES

Plasma concentrations of all three drugs were simultaneously assayed by liquid chromatography/mass spectroscopy.

RESULTS

Majority (77%) of children were receiving fixed dose combination of stavudine, lamivudine, nevirapine in the ratio of 6:30:50 mg. The median (IQR) trough and 2-hour plasma levels (µg/mL) of nevirapine, stavudine and lamivudine were 5.2 (4.0, 6.3) and 7.9 (6.0, 9.7); 0.1 (0.06, 0.16) and 1.1 (0.59, 1.6); 0.1 (0.02, 0.2) and 2.5 (1.4, 3.1), respectively. Very few children had sub-therapeutic plasma drug levels of stavudine (2.5%), lamivudine (7.6%) and nevirapine (10%). Inadequate viral suppression at 6 months follow up was significantly associated with initial high viral load, low CD4 percentage at the time of enrolment in study, and lower doses of lamivudine and stavudine.

CONCLUSIONS

The currently available generic pediatric fixed dose antiretroviral combinations in India provide adequate drug exposure in majority of children.

Antibodies that cross-neutralize the tier-2 pseudoviruses are produced in antiretroviral-naïve HIV-1-infected children from northern India

In this cross-sectional study, we evaluated the efficiency of the plasma of 38 antiretroviral-naïve HIV-1-infected children from northern India against a standard panel of pseudoviruses (3 clade C and 3 clade B) by TZM-bl assay. Neutralization potential was observed to a variable extent, with a potency ranging up to reciprocal ID(50) titers of 1967. Cross-neutralization was observed in 28.9 % (11/38) of the children. There was a significant positive correlation between viremia and neutralization efficiency against two of the viruses studied (Du172 r = 0.49; p = 0.007 and RHPA r = 0.47; p = 0.01), suggesting that persistent antigenic stimulation is necessary for the generation of broadly neutralizing antibody responses in these children. Further mapping of the epitope specificities of the neutralization determinants in the polyclonal plasma would provide important information for immunogen design.

Role of immune activation in CD4+ T-cell depletion in HIV-1 infected Indian patients

OBJECTIVES

The correlation of immune activation with CD4(+) depletion and HIV-1 disease progression has been evidenced by several studies involving mainly clade B virus. However, this needs to be investigated in developing countries such as India predominately infected with clade C virus.

MATERIALS AND METHODS

In a cross-sectional study of 68 antiretroviral treatment naïve, HIV-1 infected Indian patients, we studied the association between CD4(+) T cells, plasma HIV-1 RNA levels, and immune activation markers using unadjusted and adjusted correlative analyses.

RESULTS

Significant negative correlations of higher magnitude were observed between the CD4(+) T cell percentages and plasma HIV-1 RNA levels in the study population when adjusted for the effects of immune activation markers. However, the negative association of CD4(+) T cells with immune activation markers remained unaffected when controlled for the effects of plasma HIV-1 RNA levels.

CONCLUSIONS

Our results support the important role of immune activation in CD4(+) T cell depletion and disease progression during untreated HIV-1 infection.

Distribution of CCR2 polymorphism in HIV-1-infected and healthy subjects in North India

Substitution of V64I in CCR2 relates to delayed progression to AIDS and protects against HIV-1 infection. We examined the distribution of V64I in HIV-infected and healthy North Indian subjects. No significant difference in the allele or genotype distribution of CCR2 V64I polymorphism was observed, indicating that there is no association between CCR2 V64I polymorphism and susceptibility to HIV infection in North Indian population.

Polymorphism in the CCR5 gene promoter and HIV-1 infection in North Indians

The clinical course and outcome of human immunodeficiency virus-1 (HIV-1) infection are highly variable among individuals. CCR5 is the primary coreceptor that mediates entry of HIV-1 (R5) into permissive host cells. In this study, five SNPs (59029G/A, 59353T/C, 59356C/T, 59402A/G, and 59653C/T) in the promoter region and a deletion of 32 bp (Delta32) in the CCR5 gene were evaluated in 180 chronically HIV-1-infected North Indians. The study showed the following: (1) the protective CCR5 Delta32 allele was absent; (2) the frequency of CCR5*59402A allele in the HIV-infected people (66.4%) was higher than in healthy subjects (57.1%, p = 0.027) and in the CDC stage C patients (76%) versus stages A and B patients together (60%; p = 0.002); (3) homozygous CCR5*59402 AA genotype was significantly increased in the seropositive subjects (46.1%) compared with healthy control subjects (30.2%; p = 0.008) and in the CDC stage C patients (59.2%) compared with stage A and B subjects (37.6%, p = 0.007); and (4) an increased frequency of homozygous ACCAC haplotype was present in the seropositive stage C patients (32.4%) versus 15.6% in patients in stages A plus B (p = 0.013). These observations suggest an association of CCR5*59402A with increased likelihood of acquisition of HIV-1 and development of AIDS in the Asian Indian population. Further studies are required to confirm these findings and understand the effect of CCR5 polymorphisms on the outcome of HIV-1 infection.

Persistently high HIV seroprevalence among adult tuberculosis patients at a tertiary care centre in Delhi

BACKGROUND & OBJECTIVE

This study was designed to estimate HIV seroprevalence among tuberculosis patients presenting to tertiary care centre in Delhi.

METHODS

Cross-sectional prevalence study among all patients presenting to the inpatient and outpatient departments of All India Institute of Medical Sciences (AIIMS), New Delhi, and receiving anti-tuberculosis treatment from May 2003 to April 2005.

RESULTS

Of the 448 patients who presented to the TB clinic during the study period, 23 (5.1%) were previously tested HIV-positive. An additional 21 patients (4.6%) refused testing, and 30 (6.7%) were lost to follow up. Of the remaining 374 patients who consented to testing, 31 (8.3%) were found to be HIV-positive. Risk factors for HIV seropositivity included high-risk sexual behaviours (48% in HIV-TB co-infected vs. 6% in TB infected patients, P<0.001) and history of blood transfusion (23% vs. 5%; P=0.002).

INTERPRETATION & CONCLUSION

Previous studies from the same hospital published in 2000 and 2003 reported HIV seroprevalence among TB patients to be 0.4 and 9.4 per cent respectively. The current study documents a persistently high seropositivity among TB patients. These results emphasize the acute need for improved detection and treatment for HIV among TB patients in northern India.

Characterization of HIV-1 Gag-specific T cell responses in chronically infected Indian population

India is at the epicentre of the global HIV/AIDS epidemic in South-east Asia, predominated by subtype C infections. It is important to characterize HIV-1-specific T cell responses in this particular population with the aim of identifying protective correlates of immunity to control HIV-1 infection. In this study, we performed a comprehensive analysis of the breadth and magnitude of T cell responses directed at HIV-1 subtype C Gag, one of the most conserved HIV-1 proteins. The study population consisted of antiretroviral naive, chronic HIV-1 subtype C-infected individuals at various stages of infection. We used recent advanced techniques such as enzyme-linked immunospot (ELISPOT) assay and intracellular cytokine staining to quantify the total CD4(+) and CD8(+) T cell response to HIV-1 gag at single peptide level, regardless of HLA haplotype of the infected individual. The p24-Gag was identified as the most frequently recognized subunit protein with the greatest magnitude of CD4(+) and CD8(+) T cell responses. Stronger and broader CD8 T cell responses were recognized, contrasting with the weaker and narrower CD4 T cell responses with regard to Gag protein subunits. The magnitude of the HIV-specific interferon (IFN)-gamma responses was observed to be higher than the corresponding interleukin (IL)-2 response, indicating the persistence of antigenic load in chronically infected Indian population due to the probable dysfunction of HIV-specific, IFN-gamma-secreting CD8 T cells in absence of IL-2 help.

CDC staging based on absolute CD4 count and CD4 percentage in an HIV-1-infected Indian population: treatment implications

CD4+ T-cell levels are an important criterion for categorizing HIV-related clinical conditions according to the CDC classification system and are therefore important in the management of HIV by initiating antiretroviral therapy and prophylaxis for opportunistic infections due to HIV among HIV-infected individuals. However, it has been observed that the CD4 counts are affected by the geographical location, race, ethnic origin, age, gender and changes in total and differential leucocyte counts. In the light of this knowledge, we classified 600 HIV seropositive antiretroviral treatment (ART)-naïve Indian individuals belonging to different CDC groups A, B and C on the basis of CDC criteria of both CD4% and CD4 counts and receiver operating characteristic (ROC) curves were generated. Importantly, CDC staging on the basis of CD4% indicated significant clinical implications, requiring an early implementation of effective antiretroviral treatment regimen in HIV-infected individuals deprived of treatment when classified on the basis of CD4 counts.

Evaluation of CD4 counts and percentages in the HIV infected Indian population

This study was designed to evaluate the absolute CD4+ counts and percentages in HIV subtype C infected patients at a tertiary care hospital in northern India. The CD4+ counts of 377 HIV seropositive subjects were estimated by a FACS Calibur (BD) flow cytometer. Dual color immunophenotyping was performed on each sample, which was acquired and analysed using CellQUEST software. Discordance between CD4+ counts and percentages were found more in the early stage ie Group A (37.2%) when compared with Group B (31.6%) and Group C (28.8%), with the counts remaining in the normal range but percentages being severely depressed.

Prevalence of markers of transfusion transmissible diseases in voluntary and replacement blood donors

BACKGROUND

Transfusion of safe blood requires a safe donor. The voluntary donor movement encompasses the concept of a donor who is free from transfusion transmissible infections. It is now mandatory to screen blood for hepatitis B surface antigen, antibodies to HIV-1 and HIV-2, antibodies to hepatitis C virus, syphilis and malarial parasites.

METHODS

Between 1996 and 2002, 235 461 donors were screened for markers of hepatitis B virus, and HIV-1 and HIV-2 using commercially available ELISA kits, VDRL test for syphilis and Geimsa stain for the malarial parasite, respectively. A total of 56 476 donors were screened for hepatitis C virus antibodies from June 2001 to December 2002, using third-generation ELISA kits.

RESULTS

The proportion of voluntary donors increased from 47% to 56% during the study period. The prevalence of HIV showed a steady increase from 0.16% in 1996 to 0.3% in 2002. The prevalence of hepatitis B surface antigen decreased from 1.55% to 0.99%. VDRL reactivity did not show any trend and ranged between 0.11% and 0.66%. Hepatitis C virus antibodies showed a prevalence of 0.4%. The prevalence of all markers was significantly less in voluntary donors. Among the voluntary donors, transfusion transmissible disease markers were significantly less in student donors as compared to other donors.

CONCLUSION

A change-over to a voluntary donor service would considerably reduce the number of infectious donors and, among voluntary donors, student donors are the safest.

Spectrum of Opportunistic Infections and Profile of CD4+ Counts among AIDS Patients in North India

BACKGROUND

As the number of AIDS cases increases in India, information available among clinicians about the prevalence of opportunistic infections (OIs) is scarce. The aim of the present study was to document the characteristic OIs of HIV-infected North Indian patients along with their CD4+ counts.

PATIENTS AND METHODS

The study group consisted of subjects with confirmed serodiagnosis of HIV, attending the medical clinics at a tertiary health care center in North India. The CD4+ counts were estimated by FACS Calibur (BD) flow cytometer. Simultaneously, routine microbiology smears, cultures and serology were performed to confirm OI.

RESULTS

In this retrospective study of 421 subjects, the predominant OI was tuberculosis (47%, 189 cells/ micro l), followed by parasitic diarrhea (43.5%, 227 cells/ micro l) and oral candidiasis (25.2%, 189 cells/ micro l).

CONCLUSION

Tuberculosis was the most frequent OI in the HIV-infected patients studied, and the major mode of transmission of HIV was by sexual route. The median CD4+ counts observed were lower when compared to other studies.

Comparative evaluation of various commercial assays for diagnosis of dengue fever

Dengue fever (DF) is endemic in India and dengue hemorrhagic fever (DHF) has been reported with increasing frequency in the last decade. We evaluated three commercial assays for detection of antibodies to dengue virus, to assess their performance in a diagnostic laboratory. Sera from 58 patients collected during a febrile outbreak in New Delhi in 1997 were studied. The methods evaluated were MRL Diagnostic Dengue Fever Virus IgM Capture ELISA, Pan Bio Dengue Duo IgM and IgG Capture ELISA and Pan Bio Rapid Immunochromatographic test. The MRL ELISA correctly identified 97.8% (43 of 44) of samples as dengue positive while the Pan Bio Duo ELISA and Pan Bio RIT identified 95.45% (42 of 44). The sensitivities of both Pan Bio Duo ELISA and Pan Bio RIT for primary dengue and secondary dengue were 100% and 93.54% respectively. The specificity of three assays were MRL IgM ELISA 100%, Pan Bio Duo ELISA 92.8% and Pan Bio RIT 85.7%.

Study of the first contact management profile of cases of infectious keratitis: a hospital-based study

PURPOSE

To study the management pattern and examine the role of cultures and antibiotic sensitivity testing in infectious keratitis.

METHODS

A retrospective analysis of the demographic, clinical, and microbiological data was performed in 100 consecutive patients with infectious keratitis. The main parameters evaluated were nature of first contact with the health care services, investigations undertaken, treatment initiated, and the time interval between presentation to the first medical contact and to our center. Finally, the reports of culture and antibiotic sensitivity testing undertaken at our center were evaluated.

RESULTS

In 70% of cases, ophthalmologists in independent practice were the first medical contact. Direct microscopy of the corneal scraping was undertaken in only 6% of cases, whereas culture and sensitivity studies had not been performed in any of the patients. Forty-six percent of the patients were prescribed 0.3% ciprofloxacin eyedrops in an inadequate dosage. Broad-spectrum fortified antibiotics eye drops had not been prescribed in any of the cases. At our center, positive cultures were obtained in 73.86% of cases and the most common organism isolated was coagulase-negative Staphylococcus (33.84%), followed by Pseudomonas aeruginosa (15.38%). A large number of the isolates demonstrated resistance to the recommended antibiotic therapy.

CONCLUSIONS

Failure to implement standard management protocol for infectious keratitis at first contact is a major factor contributing to ocular morbidity in India.

Infectious crystalline keratopathy

PURPOSE

To review the diagnosis, microbial and pathological features, pathogenesis, and treatment of infectious crystalline keratopathy (ICK).

METHODS

We reviewed the literature on infectious crystalline keratopathy.

RESULTS AND CONCLUSIONS

ICK is an indolent corneal infection in which needle-like, branching crystalline opacities are seen within the corneal stroma, in the absence of appreciable corneal or anterior segment inflammation. In most cases it occurs as a complication of corneal surgery and keratitis, with an alpha-hemolytic Streptococcus being the cause of infection. Discontinuation of topical steroids with aggressive antibiotic therapy may suffice, but continued infection, vascularization, or scar formation may affect visual acuity and require penetrating keratoplasty.

Dengue virus infection during post-epidemic period in Delhi, India

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are major public health problems in India. During the period following an epidemic, a study was carried out using virological and serological tests for confirmation of suspected cases of dengue virus infection in fever cases presenting to the All India Institute of Medical Sciences. Serum samples of suspected DF/DHF cases were processed from January to December 1997. In 37 samples from patients with fever of less than 5-day duration, received on ice, virus isolation was attempted in C6/36 clone of Aedes albopictus cell line, followed by indirect fluorescent antibody staining with monoclonal antibodies to dengue viruses 1 to 4. One hundred and forty-three serum samples from patients with more than 5 days fever were tested for dengue specific IgM antibody by either MAC-ELISA or a rapid immunochromatographic assay. Dengue virus type 1 was demonstrated by culture in 8 (21.6%) of 37 serum samples and IgM antibody could be detected in 42 (29.4%) of the 143 serum samples by the serological methods. The peak of dengue virus infection was seen from September to November 1997.

Topical pefloxacin in bacterial keratitis

PROBLEM

To evaluate the clinical efficacy and safety of topical pefloxacin 0.3% drops as the sole antibiotic used to treat culture positive bacterial corneal ulcers.

METHODS

Forty two consecutive Gram's smear-positive cases of bacterial corneal ulcers were enrolled for this prospective open labelled clinical trial. All patients underwent a complete clinical and microbiological work up and were put on topical 0.3% pefloxacin drops with supportive cycloplegic, vitamins and antiglaucoma therapy. Of 42 cases, 4 cases of mycotic keratitis and 6 culture negative cases were excluded from the study.

RESULTS

Positive microbiologic cultures were obtained in 84.2% (32 of 38) cases. Staphylococcus aureus (14/32; 43.7%) and coagulase negative Staphylococci (12/32; 37.5%) were the two most common organisms isolated. Resolution of the corneal ulcer was achieved in 31 out of 32 cases (96.9%) with a mean duration of 9.3+/-5.3 days (range 3-21 days). Best corrected visual acuity of 20/200 or better was achieved in 65.6% of cases at 4 weeks post resolution. Corneal deposits were observed in one case which disappeared 8 days following discontinuation of therapy.

CONCLUSIONS

Topical pefloxacin is effective as a single antibiotic agent for the treatment of bacterial keratitis.

Acute hemorrhagic conjunctivitis due to enterovirus 70 in India

An outbreak of acute hemorrhagic conjunctivitis occurred in Delhi, India, during August and September 1996. The etiologic agent was confirmed as enterovirus type 70 by a modified centrifugation-enhanced culture method followed by immunofluorescence and neutralization tests. After nearly a decade, this virus is reemerging as a cause of acute hemorrhagic conjunctivitis in India.

Corneal superinfection in acute hemorrhagic conjunctivitis

PURPOSE

This study aimed to evaluate the clinical profile, microbial spectrum, management modalities, and visual outcome in cases of corneal superinfection that occurred after an epidemic of acute hemorrhagic conjunctivitis.

METHOD

A retrospective analysis of 14 eyes of 13 patients who were referred to a tertiary eye-care center with corneal ulceration after an episode of acute hemorrhagic conjunctivitis was undertaken. The parameters analyzed were age, sex, prior use of topical medications, predisposing factors, ulcer characteristics, organisms isolated, success of medical therapy and surgery, and visual outcome.

RESULTS

A definite history of topical corticosteroid use to treat acute hemorrhagic conjunctivitis was elicited in 12 (86%) eyes. Cultures were positive in 86% (12/14) eyes. Organisms isolated were Pseudomonas aeruginosa (three eyes, 25%), Fusarium species (three eyes, 25%), Aspergillus species (two eyes, 16%), and Staphylococcus aureus (two eyes, 16%). Mixed infection occurred in two patients. After discontinuation of topical corticosteroids, all patients received antimicrobial therapy. The keratitis resolved in seven eyes. Therapeutic penetrating keratoplasty was required in five eyes. Two patients were lost to follow-up.

CONCLUSIONS

Corneal superinfection may occur after acute hemorrhagic conjunctivitis. Use of topical corticosteroids to treat acute hemorrhagic conjunctivitis may predispose an already compromised cornea to develop microbial keratitis and such a practice should be discouraged.