Presentation to HIV care and antiretroviral therapy initiation and response in clinical practice from 2003 through 2013

Universal HIV screening and treatment initiation of HIV-positive persons are well-established standards. However, late presentation to care is a barrier to early antiretroviral therapy (ART) and prevention of HIV transmission. We sought to determine the immunodeficiency at presentation to care and characterize the initiation and response to ART among HIV-positive persons over 2003–2013 in our urban HIV clinical practice at the Cleveland Clinic. Using a retrospective cohort study design, we assessed the CD4 cell count of HIV-positive patients at entry into care for each year and evaluated the trend over time. For patients who initiated treatment, we assessed the pretreatment CD4 cell count, consistency of timing and regimen with US treatment guidelines, and HIV RNA level at one-year and last follow-up visits. Regression analyses were used to determine predictors of study outcomes. We found that the cohort (N = 452) median CD4 cell count at presentation to care was 297 cells/mm3 (inter-quartile range: 104–479 cells/mm3), without any significant change over time (P = 0.62), and with 37% and 21% of presentations being late and advanced, respectively. Guideline-consistency (85%–100%) and regimen-consistency (41%–100%) were moderate to high and improved over time. Virologic suppression (<400 copies/ml) at one year and last follow-up was high (79% and 92%) and associated with regimen selection and durability. We conclude that CD4 cell count at first presentation to HIV care remained less than 350 cells/mm3 for 11 years in our clinical practice, despite advances in HIV testing and treatment guidelines. Early diagnosis and linkage to care and treatment are critical for ending the HIV epidemic.

Detection of Herpes Simplex Virus and Varicella-Zoster Virus by Traditional and Multiplex Molecular Methods

Objectives

To compare multiplex nucleic acid amplification tests (NAATs) that detect and differentiate herpes simplex virus (HSV) and varicella-zoster virus (VZV) with traditional virologic assays.

Methods

The HSV ELVIS Test System (Quidel, San Diego, CA) and/or Light Diagnostics VZV direct fluorescent antibody (DFA) kit (Millipore Sigma, Billerica, MA), as well as an ARIES HSV 1&2/VZV assay (Luminex, Austin, TX) and the Solana HSV1 + 2/VZV Assay (Quidel), were performed on non-cerebrospinal fluid specimens.

Results

The sensitivities/specificities for the ELVIS, Aries, and Solana assays for HSV were 71.1%/93.2%, 94.9%/93.2%, and 94.7%/100%, respectively. The sensitivities/specificities for the DFA, Aries, and Solana assays for VZV were 71.4%/100%, 100%/96.0%, and 95.3%/100%, respectively. HSV and VZV were detected but clinically unsuspected in 5.4% and 4.2% of the specimens, respectively.

Conclusions

Both NAAT assays were comparable and more sensitive than traditional methods. The recovery of unsuspected HSV and VZV from clinical specimens supports the implementation of a combined HSV/VZV assay.

Viral Diagnostics

This chapter discusses recent developments in diagnostics for cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), community respiratory viruses (CRVs), parvovirus, hepatitis viruses, HIV, and other viral agents of importance in solid organ and hematopoietic stem cell transplantation.

Low Indeterminate Rates Associated With Use of the QuantiFERON-TB Gold In-Tube Test in Children With Inflammatory Bowel Disease on Long-term Infliximab

BACKGROUND

Tumor necrosis factor alpha (TNF-α) inhibitors are linked with increased risk of reactivation of active tuberculosis. The QuantiFERON-TB Gold In-Tube test is approved for screening latent tuberculosis infection in children and adults. There are limited data on the test performance in children on long-term treatment with TNF-α inhibitors. The objective of this study was to assess the proportion of indeterminate results for the QuantiFERON-TB Gold In-Tube in children with inflammatory bowel disease (IBD) on long-term infliximab treatment and to evaluate the range of interferon-γ responses to mitogen.

METHODS

A single-center prospective study of children 5 to 19 years of age with IBD on long-term infliximab treatment (>3 months). Each child was assessed for tuberculosis exposure risk and had blood drawn for the QuantiFERON-TB Gold In-Tube. Data on the range of interferon-γ responses and final QuantiFERON-TB Gold In-Tube test results were collected.

RESULTS

Ninety-three children were included, with a median age of 16 years. The median total duration of infliximab therapy was 34 months (range, 3-119 months). The QuantiFERON-TB Gold In-Tube was indeterminate in 1 patient (1.1%), positive in 2 patients, and negative in 90 patients. The maximum interferon-γ response to mitogen (10 IU/mL) was observed in 82 patients (88%), with only 1 patient having an inadequate response. The proportion of indeterminate results was significantly lower than the prospectively hypothesized rate of 8%, based on prior studies in nonimmunosuppressed patients (P = 0.004).

CONCLUSIONS

Pediatric patients with IBD on long-term treatment with infliximab had an adequate interferon-γ response to mitogen and a low indeterminate rate when assessed with the QuantiFERON-TB Gold In-Tube test. This study demonstrates a robust interferon gamma response to phytohemagglutinin stimulation in a pediatric population on long-term therapy with infliximab. The QuantiFERON-TB Gold In-Tube test may therefore be useful as a periodic screening tactic for latent TB in children on long-term infliximab therapy.

Mailed Human Papillomavirus Self-Collection With Papanicolaou Test Referral for Infrequently Screened Women in the United States

BACKGROUND

Testing for high-risk human papillomavirus (HPV) infection using mailed, self-collected samples is a promising approach to increase screening in women who do not attend clinic screening at recommended intervals.

METHODS

To assess this intervention among high-risk women in the United States, 429 women without a Papanicolaou (Pap) test in 4 or more years (overdue by US guidelines) were recruited from the general population. Participants aged 30 to 65 years were mailed a kit to self-collect a cervicovaginal sample at home, return the sample by mail, and receive HPV results by telephone, with referral to follow-up cytological Pap testing at a local clinic. Cervicovaginal self-samples were collected with a Viba brush, stored in Scope mouthwash, and tested by Hybrid Capture 2. Data were collected in 2010 to 2011 and analyzed in 2017.

RESULTS

Two-thirds (64%) of participants returned a self-collected sample, of whom 15% tested HPV DNA positive. Human papillomavirus self-test-positive women reported higher rates of follow-up Pap tests (82%) than did those with self-test negative results (51%). No demographic differences were found in self-test return rate or HPV positivity. High acceptability was reported in participant surveys: most women (81%) had "mostly positive" overall thoughts about the self-test, and most reported being comfortable receiving the kit in the mail (99%), returning their self-collected sample by mail (82%), and receiving their test results by telephone (97%).

CONCLUSIONS

Conducting HPV self-testing through population-based recruitment, mailed kit delivery and return by mail, and results delivery by telephone has the potential to reach a broad segment of US underscreened women.

Multi-center evaluation of the cobas® Liat® Influenza A/B & RSV assay for rapid point of care diagnosis

Point of Care Testing (POCT) provides the capability for rapid laboratory test results in patient care environments where a traditional clinical laboratory is not available. POCTs have shorter turn-around times (TATs), they may be performed by non-laboratory personnel, and the need for transport time is eliminated. The Food and Drug Administration (FDA) recently granted Clinical Laboratory Improvements Amendment (CLIA) waiver status to the cobas^® Influenza A/B & RSV assay, a rapid, accurate point-of-care test for Influenza and respiratory syncytial virus (RSV) performed on the Liat^® System. The performance characteristics of this test were determined though a multi-site study consisting of different point of care testing environments. Prospectively collected Nasopharyngeal (NP) swabs from 1361 patients seen at 8 primary care clinics and 4 emergency departments (EDs) and 295 retrospectively identified specimens were tested for Influenza A/B and RSV on the cobas^® Liat^® platform. Performance characteristics were determined through comparison to ProFlu+, a laboratory-based PCR test for Influenza A/B and RSV (reference test). Discordant specimens were adjudicated following bi-directional sequencing. The cobas^® Influenza A/B and RSV assay showed sensitivities of 99.6%, 99.3%, and 96.8% for Influenza A, Influenza B, and RSV, respectively as determined from percent positive agreement (PPA) following comparison to the reference test. Sequencing confirmed cobas^® Influenza A/B and RSV results in 49.2% of reference test discordant specimens, while crossing threshold data suggest increased sensitivity compared to the reference test. The cobas^® Influenza A/B and RSV assay was found to be a rapid, sensitive POCT for the detection of these viruses, and provides laboratory-quality PCR-based diagnostic results in point of care settings.

A comparison of hospitalized children with enterovirus D68 to those with rhinovirus

BACKGROUND

During the Fall of 2014, numerous children were hospitalized with asthma or respiratory distress related to Enterovirus D68 (EV-D68). A large proportion initially tested positive for rhinovirus. During this period our laboratory noted a cross-reactivity between EV-D68 and the rhinovirus component of the GenMark multiplex respiratory viral panel. Many other laboratories used assays not designed to distinguish these Picornoviridae.

METHODS

To compare the presentation and outcomes of patients with rhinovirus and EV-D68, 103 GenMark rhinovirus positive nasopharyngeal swabs from hospitalized children were retested for EV-D68.

RESULTS

EV-D68 positive patients versus EV-D68 negative patients were more likely to have a history of asthma (33.3% vs. 11.0%, P = 0.02) and to present with acute respiratory illness (66.7% vs. 40.2%, P = 0.048), especially status asthmaticus (47.6% vs. 2.4%, P < 0.001). On admission they had more wheezing, respiratory distress, and lower respiratory tract involvement, and were more likely to be treated with steroids and discharged home on asthma medications. Respiratory viral coinfection was less common in EV-D68 positive vs EV-D68 negative patients. In patients without a respiratory viral coinfection the overall findings were similar.

CONCLUSION

Patients with EV-D68 versus rhinovirus were more likely to have a history of asthma, to present with status asthmaticus, to wheeze on admission, and to receive treatment with asthma medications in hospital and at discharge. The inability of common assays to distinguish EV-D68 from rhinoviruses raises the possibility that the role of EV-D68 as a viral trigger of asthma has been under appreciated. Pediatr Pulmonol. 2017;52:827-832. © 2017 Wiley Periodicals, Inc.

Prenatal Exposure to Respiratory Syncytial Virus Alters Postnatal Immunity and Airway Smooth Muscle Contractility during Early-Life Reinfections

Maternal viral infections can have pathological effects on the developing fetus which last long after birth. Recently, maternal-fetal transmission of respiratory syncytial virus (RSV) was shown to cause postnatal airway hyperreactivity (AHR) during primary early-life reinfection; however, the influence of prenatal exposure to RSV on offspring airway immunity and smooth muscle contractility during recurrent postnatal reinfections remains unknown. Therefore, we sought to determine whether maternal RSV infection impairs specific aspects of cell-mediated offspring immunity during early-life reinfections and the mechanisms leading to AHR. Red fluorescent protein-expressing recombinant RSV (rrRSV) was inoculated into pregnant rat dams at midterm, followed by primary and secondary postnatal rrRSV inoculations of their offspring at early-life time points. Pups and weanlings were tested for specific lower airway leukocyte populations by flow cytometry; serum cytokine/chemokine concentrations by multiplex ELISA and neurotrophins concentrations by standard ELISA; and ex vivo lower airway smooth muscle (ASM) contraction by physiological tissue bath. Pups born to RSV-infected mothers displayed elevated total CD3+ T cells largely lacking CD4+ and CD8+ surface expression after both primary and secondary postnatal rrRSV infection. Cytokine/chemokine analyses revealed reduced IFN-γ, IL-2, IL-12, IL-17A, IL-18, and TNF-α, as well as elevated nerve growth factor (NGF) expression. Prenatal exposure to RSV also increased ASM reactivity and contractility during early-life rrRSV infection compared to non-exposed controls. We conclude that maternal RSV infection can predispose offspring to postnatal lower airways dysfunction by altering immunity development, NGF signaling, and ASM contraction during early-life RSV reinfections.

Use of an HBV-DNA Hybridization Assay in the Evaluation of Equivocal Hepatitis B Virus Tests in Solid Organ Donors

Context

Serological markers for the hepatitis B virus are routinely used in the evaluation of potential organ donors. However, serological tests can be associated with significant false or equivocal results and may not be indicative of the true risk of hepatitis B infection. Studies have recently questioned the significance of an isolated hepatitis B core antibody test in evaluating the suitability of solid organs for transplantation. The ability to detect hepatitis B virus DNA may prove useful when the diagnosis of hepatitis B infection is in doubt.

Design

Serum samples from 16 donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests were retrospectively tested for the presence of hepatitis B DNA. Any available follow-up data on the placement of organs from these donors was obtained.

Results

One of the 16 (6.3%) donors tested positive for the presence of hepatitis B DNA, but organs from this donor were not recovered or transplanted. Follow-up on 14 organs recovered and transplanted from 6 donors in this group did not show clinical and/or laboratory evidence of hepatitis B infection in the recipients.

Conclusions

In our donor population, there was a low incidence (6.3%) of donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests who subsequently demonstrated the presence of detectable hepatitis B DNA. Posttransplantation follow-up of the recipients of 14 recovered organs failed to demonstrate any cases of posttransplant hepatitis B infection.

Preanalytic process linked to spuriously elevated HIV viral loads: improvement on an FDA-approved process

The processing of specimens often occurs in a central processing area within laboratories. We demonstrated that plasma centrifuged in the central laboratory but allowed to remain within the primary tube following centrifugation was associated with spuriously elevated HIV viral loads compared with recentrifugation of the plasma just prior to testing.

Absence of human herpesvirus 6B detection in association with illness in children undergoing cancer chemotherapy

The lymphotropic herpesviruses, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6B (HHV-6B) can reactivate and cause disease in organ transplant recipients; the contributions of HHV-6A and HHV-7 to disease are less certain. Less is known about their pathogenic roles in children undergoing treatment for malignancies. Children with newly diagnosed cancer were followed for 24 months. Clinical information and blood samples were collected during routine visits and during acute visits for fever or possible viral infections. Lymphotropic herpesvirus DNA in blood was measured by polymerase chain reaction (PCR). Although HHV-6B DNA was detected at least once in about half of the patients; the other viruses were seldom detected. There was no association between HHV-6B detection and individual acute clinical events, however, HHV-6B detection was more common in children who experienced more frequent acute clinical events. In children being treated for various malignancies, HHV-6B detection was common, but was not associated with individual events of acute illness. Thus, if HHV-6B is not assessed longitudinally, clinical events may be misattributed to the virus. The elevated frequency of detection of HHV-6B in sicker children is consistent with prior reports of its detection during apparently unrelated acute clinical events. J. Med. Virol. 88:1427-1437, 2016. © 2016 Wiley Periodicals, Inc.

Reducing the Rates of Indeterminate Results of the QuantiFERON-TB Gold In-Tube Test During Routine Preemployment Screening for Latent Tuberculosis Infection Among Healthcare Personnel

We implemented the QuantiFERON-TB Gold (QFT-G) In-Tube test to identify latent tuberculosis infection among potential employees prior to employment. The rates of indeterminate QFT-G In-Tube test results were higher than expected and prompted an investigation that led to successful interventions (eg, manual vortexing before incubation and the use of a modified in-tube method). The tracking of indeterminate results is suggested as an important quality control measure.

Multicenter comparison of laboratory performance in cytomegalovirus and Epstein-Barr virus viral load testing using international standards

BACKGROUND

Infections with cytomegalovirus (CMV) and Epstein-Barr virus (EBV) remain important in solid organ transplantation. Quantitative viral nucleic acid testing is a major advance to patient management. These assays are limited by a lack of standardization, resulting in viral load measurements that differ among clinical laboratories. The variability in viral load measurements makes interpretation of multicenter clinical trials data difficult. This study compares the current practices in CMV and EBV viral load testing at four large transplant centers participating in multicenter Clinical Trials in Organ Transplantation and the Clinical Trials in Organ Transplantation in Children (CTOT and CTOTC).

METHODS

Viral load testing was performed on well-defined viral preparations according to standard operating procedures at each site.

RESULTS

Among centers, CMV viral load testing was accurate compared to WHO International Standards and within acceptable variation for this testing method. Epstein-Barr virus viral load data were more variable and less accurate despite the use of international standards.

CONCLUSIONS

These data suggest that comparison of CMV, but not EBV, viral load measurements at these sites is possible using current assays and control standards. Standardization of these assays is facilitated using the WHO International Standards and will allow comparison of viral load results among transplant centers. Assay standardization must be performed prior to initiation of multicenter trials.

Hybrid Capture 2 human papilloma virus testing for head and neck cytology specimens

INTRODUCTION

High-risk human papilloma virus (hrHPV)-associated head and neck (HN) squamous cell carcinomas (SCCs) have important differences from non-hrHPV-related HNSCCs. A highly sensitive and specific test for HPV in cytology fine-needle aspirations (FNAs) would be useful, as it has the potential to alter therapy.

MATERIALS AND METHODS

Patients with an HN FNA diagnosed as SCC or suspicious for SCC were included. Hybrid Capture 2 (HC2) was performed on residual rinse material and chromogenic in situ hybridization (CISH) for hrHPV was performed on the cell block. HC2-positive samples were genotyped for HPV types 16, 18, and 45. "Gold standard" p16 and CISH testing was performed on histologic material from the primary tumor. Tumors concordantly positive for p16 and CISH were considered hrHPV-positive, concordantly negative were considered hrHPV-negative, and discordant results were considered hrHPV-equivocal.

RESULTS

A total of 96 FNAs from 95 patients were included. Surgical material was available in 80 patients. Of those, 29 patients (36%) were positive for hrHPV by "gold standard" testing, and 3 patients (4%) had equivocal results. HC2 was 72% sensitive and 100% specific for hrHPV. Sixty percent of HC2-positive aspirate samples were positive for HPV16. CISH was 61% sensitive and 79% specific for hrHPV. HC2 had a significantly better sensitivity and specificity than did CISH on paired sample analysis (P < .05).

CONCLUSIONS

HC2 is a highly sensitive and specific assay for the detection of hrHPV in HN FNA samples. This new application of a familiar, widely available testing method has the potential to be clinically useful in the management of patients with HNSCC.

KIR and HLA interactions are associated with control of primary CMV infection in solid organ transplant recipients

Cytomegalovirus (CMV) infection remains a major source of morbidity and mortality in solid organ transplant recipients. Killer immunoglobulin-like receptors(KIR) are genetically polymorphic natural killer(NK) cell receptors important in antiviral responses. A retrospective, single-center cohort study was performed to study the interaction of KIR genotype and primary control of CMV infection after transplantation.Time to first CMV viremia was determined for a cohort of 531 CMV serology donor positive/recipient negative solid organ transplant recipients. Of the KIR genes,KIR2DL3 and KIR2DS2 were most strongly associated with time to CMV viremia in random survival forest analysis. As KIR2DL3 and KIR2DS2 both interact with HLA-C1, these interactions were evaluated. Seventy six recipients were found to be positive for both KIR2DL3 and KIR2DS2 and expressed only HLA-C1 antigens in both recipient and donor. These patients had a substantially reduced hazard of CMV viremia in the first year after solid organ transplantation (hazard ratio 0.44, 95% CI 0.27–0.72, p=0.0012). In KIR2DL3+/KIR2DS2+/HLA-C1/1 recipients who received an organ from a non-C1/1 donor, this protective effect was not observed. These results improve our understanding of human NK cell function in primary CMV infection after transplant.

Impact of analytical variability on clinical interpretation of multiplex pneumococcal serology assays

The response to pneumococcal vaccination can be used to assess a patient's humoral immune response to polysaccharide antigens. Multiplex assays measuring serotype-specific levels of pneumococcal antibodies are often used for this purpose, and clinical algorithms have been published to assist in the definition of an adequate immune response. We evaluated whether interlaboratory variability in multiplex pneumococcal serology assays would affect the clinical classification of the immune response. Specimens from 57 patients were analyzed at three reference laboratories with different multiplex assays to measure pneumococcal serology. Analytical correlation and clinical agreement in the classification of a patient's vaccination status by the three methods were compared. Although substantial variation in the quantitative antibody levels measured by different laboratories was seen, the qualitative classification of individual serologic results showed a high degree of agreement between labs and the ultimate classification of a patient as "protected" or "nonprotected" was the same for most patients. The majority of discordant classifications were driven by a systematic bias in results from one of the assays rather than by random error. These data suggest that the use of integrated assessments based on multiple serotypes can compensate for much of the analytical variability seen between laboratories. Knowledge of the analytical performance characteristics of a particular assay is most important when evaluating patients with results near clinical cut points.

Assessment of cytomegalovirus-specific cell-mediated immunity for the prediction of cytomegalovirus disease in high-risk solid-organ transplant recipients: a multicenter cohort study

BACKGROUND

Cytomegalovirus (CMV) disease remains an important problem in solid-organ transplant recipients, with the greatest risk among donor CMV-seropositive, recipient-seronegative (D(+)/R(-)) patients. CMV-specific cell-mediated immunity may be able to predict which patients will develop CMV disease.

METHODS

We prospectively included D(+)/R(-) patients who received antiviral prophylaxis. We used the Quantiferon-CMV assay to measure interferon-γ levels following in vitro stimulation with CMV antigens. The test was performed at the end of prophylaxis and 1 and 2 months later. The primary outcome was the incidence of CMV disease at 12 months after transplant. We calculated positive and negative predictive values of the assay for protection from CMV disease.

RESULTS

Overall, 28 of 127 (22%) patients developed CMV disease. Of 124 evaluable patients, 31 (25%) had a positive result, 81 (65.3%) had a negative result, and 12 (9.7%) had an indeterminate result (negative mitogen and CMV antigen) with the Quantiferon-CMV assay. At 12 months, patients with a positive result had a subsequent lower incidence of CMV disease than patients with a negative and an indeterminate result (6.4% vs 22.2% vs 58.3%, respectively; P < .001). Positive and negative predictive values of the assay for protection from CMV disease were 0.90 (95% confidence interval [CI], .74-.98) and 0.27 (95% CI, .18-.37), respectively.

CONCLUSIONS

This assay may be useful to predict if patients are at low, intermediate, or high risk for the development of subsequent CMV disease after prophylaxis.

CLINICAL TRIALS REGISTRATION

NCT00817908.

Challenges of interferon-γ release assay conversions in serial testing of health-care workers in a TB control program

BACKGROUND

Clinical data with use of serial interferon-γ release assay (IGRA) testing in US health-care workers (HCWs) are limited.

METHODS

A single-center, retrospective chart review was done from 2007 to 2010 of HCWs who underwent preemployment QuantiFERON-TB Gold In-Tube testing. Demographic data, bacille Calmette-Guérin history, prior tuberculin skin test result if done, and baseline and serial IGRA values were obtained. The number of IGRA converters and reverters and their subsequent management by infectious disease physicians were reviewed. Quantitative IGRA-negative values were not available.

RESULTS

A total of 7,374 IGRAs were performed on newly hired HCWs. Of these tests, 486 (6.6%) were positive at baseline, 305 (4.1%) were indeterminate, and 6,583 (89.3%) were negative. From 2007 to 2010, 52 of 1,857 HCWs (2.8%) with serial IGRA tests were identified as converters, with a serial IGRA median value of 0.63 IU/mL. Seventy-one percent of HCWs with IGRA conversion had values ≤ 1 IU/mL. None of the converters had active TB or were part of an outbreak investigation.

CONCLUSIONS

Clinical significance of most QuantiFERON-TB Gold In-Tube conversions in serial testing remains a challenging task for clinicians. The use of a single cutoff point criterion for IGRA may lead to overdiagnosis of new TB infections. Clinical assessment and evaluation may help to prevent unnecessary therapy in these cases. The criteria for defining conversions and reversions by establishing new cutoffs needs to be evaluated further, especially in HCWs.

Comparative clinical evaluation of the IsoAmp(®) HSV Assay with ELVIS(®) HSV culture/ID/typing test system for the detection of herpes simplex virus in genital and oral lesions

BACKGROUND

The novel IsoAmp(®) HSV Assay employs isothermal helicase-dependent nucleic acid amplification and a user-friendly disposable test device to achieve rapid (<1.5h), on-demand qualitative detection of herpes simplex virus (HSV) types 1 and 2 in oral and genital lesions.

OBJECTIVES

To compare performance of the IsoAmp(®) HSV Assay with the ELVIS(®) HSV ID/typing (shell-vial culture and DFA) test system for clinical specimens collected from oral and genital lesions in symptomatic patients.

STUDY DESIGN

A total of 994 specimens from male and female genital and oral lesions were obtained and evaluated at five study sites in the United States. Results from the IsoAmp(®) HSV Assay were compared to those from the ELVIS(®) system. Separate reproducibility studies were performed at 3 sites using a blinded and randomized study panel. Discrepant specimens were resolved by bidirectional sequencing analysis.

RESULTS

After discrepant analysis, overall agreement of IsoAmp(®) with ELVIS(®) was 98.8% with 37.0% overall prevalence (all study sites). Reproducibility rates were well within expectations.

CONCLUSION

The IsoAmp(®) HSV Assay showed excellent performance for clinical use for detection of HSV in genital and oral specimens. In contrast to ELVIS(®), IsoAmp(®) HSV offers excellent sensitivity plus rapid on-demand testing and simpler specimen preparation.

Cervical cancer screening: Less testing, smarter testing

In its 2009 recommendations for cervical cancer screening, the American College of Obstetricians and Gynecologists (ACOG) calls for less-frequent but smarter screening that integrates testing for human papillomavirus (HPV) infection with the Papanicolaou (Pap) test. We review the recommendations from this and other organizations and how and why they are evolving.

Effect of the influenza A (H1N1) live attenuated intranasal vaccine on nitric oxide (FE(NO)) and other volatiles in exhaled breath

For the 2009 influenza A (H1N1) pandemic, vaccination and infection control were the main modes of prevention. A live attenuated H1N1 vaccine mimics natural infection and works by evoking a host immune response, but currently there are no easy methods to measure such a response. To determine if an immune response could be measured in exhaled breath, exhaled nitric oxide (FE(NO)) and other exhaled breath volatiles using selected ion flow tube mass spectrometry (SIFT-MS) were measured before and daily for seven days after administering the H1N1 2009 monovalent live intranasal vaccine (FluMist®, MedImmune LLC) in nine healthy healthcare workers (age 35 ± 7 years; five females). On day 3 after H1N1 FluMist® administration there were increases in FE(NO) (MEAN±SEM: day 0 15 ± 3 ppb, day 3 19 ± 3 ppb; p < 0.001) and breath isoprene (MEAN±SEM: day 0 59 ± 15 ppb, day 3 99 ± 17 ppb; p = 0.02). MS analysis identified the greatest number of changes in exhaled breath on day 3 with 137 product ion masses that changed from baseline. The exhaled breath changes on day 3 after H1N1 vaccination may reflect the underlying host immune response. However, further work to elucidate the sources of the exhaled breath changes is necessary.

A rapid and simple isothermal nucleic acid amplification test for detection of herpes simplex virus types 1 and 2

BACKGROUND

A simple and rapid IsoAmp HSV assay has been developed for qualitative detection of herpes simplex virus (HSV) types 1 and 2 from genital lesions. Sample preparation involved a simple dilution step and the diluted specimens were directly added to the device and amplified by isothermal helicase-dependent amplification (HDA). Amplification products were then detected by a DNA strip embedded in a disposable cassette without any instrument. The total test turn-around time is less than 1.5h from specimen processing to result reporting.

OBJECTIVES

To evaluate the analytical and clinical performance of the IsoAmp HSV assay as well as the robustness and reproducibility of the assay.

STUDY DESIGN

The analytical sensitivity of the IsoAmp HSV assay was determined using both HSV-1 and HSV-2. Clinical performance was evaluated using 135 frozen specimens collected from patients with suspected HSV infection in genital area.

RESULTS

The analytical sensitivity of the assays was 5.5 and 34.1 copies/reaction for HSV-1 and HSV-2 respectively with a 95% confidence interval. When the herpes viral culture was used as the reference standard, the clinical sensitivity and specificity of the IsoAmp HSV assay were 100.0% and 96.3% respectively. The inter-laboratory reproducibility achieved an overall 97.5% agreement by testing a total of 80 blinded HSV-1 samples among five laboratories.

CONCLUSION

Adequate analytical and clinical performance of the IsoAmp HSV assay was demonstrated. This assay is simple to perform and has acceptable inter-laboratory reproducibility.

Analytical performance of the Investigational Use Only Cervista HPV HR test as determined by a multi-center study

BACKGROUND

Any HPV test designed to be utilized in cervical cancer screening programs should be highly validated both analytically and clinically.

OBJECTIVES

The Investigational Use Only (IUO) Cervista HPV HR test is designed to detect 14 high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). The analytical performance of the Cervista HPV HR test was characterized in a multi-center study.

RESULTS

Analytical sensitivity for the 14 high-risk HPV types that the test is designed to detect ranged from 1,250 copies to 7,500 copies per reaction depending on HPV type. Accuracy compared to PCR with bi-directional sequencing was 91.4% [95% CI: 86.5 95.0%]. The reproducibility, when tested at three different testing centers, resulted in an overall inter-run reproducibility (between day/within site) agreement of 98.8% [1-sided 95% Confidence Lower Limit = 96.9%] and an overall inter-site reproducibility (between site) agreement of 98.7% [1-sided 95% Confidence Lower Limit = 97.9%]. The Cervista HPV HR test showed no cross-reactivity with DNA from seven non-oncogenic HPV types or 17 different infectious agents at up to 10(7) copies per reaction.

CONCLUSIONS

The analytical performance of the Cervista HPV HR test demonstrates sufficient analytical performance for use in cervical cancer screening. As with any clinical laboratory test, analytical characteristics must be evaluated in light of the clinical performance of this assay.

Diagnostic performance of a new automated heterophile antibody test in adults and children

Epstein-Barr virus serologic profiles were obtained from 618 patients using an automated platform, including the new BioPlex heterophile assay. When compared with 2 IgM viral capsid antigen (VCA) assays and a predicate heterophile assay, the BioPlex heterophile assay was more likely to be associated with serologic patterns of acute infection.

Beta-herpesviruses in febrile children with cancer

We conducted a cross-sectional study of beta-herpesviruses in febrile pediatric oncology patients (n = 30), with a reference group of febrile pediatric solid-organ transplant recipients (n = 9). One (3.3%) of 30 cancer patients and 3 (33%) of 9 organ recipients were PCR positive for cytomegalovirus. Four (13%) of 30 cancer patients and 3 (33%) of 9 transplant recipients had human herpesvirus 6B (HHV-6B) DNAemia, which was more common within 6 months of initiation of immune suppression (4 of 16 vs. 0 of 14 cancer patients; p = 0.050). HHV-6A and HHV-7 were not detected. No other cause was identified in children with HHV-6B or cytomegalovirus DNAemia. One HHV-6B-positive cancer patient had febrile disease with concomitant hepatitis. Other HHV-6B-positive children had mild "viral" illnesses, as did a child with primary cytomegalovirus infection. Cytomegalovirus and HHV-6B should be included in the differential diagnosis of febrile disease in children with cancer.

Bortezomib induces caspase-dependent apoptosis in Hodgkin lymphoma cell lines and is associated with reduced c-FLIP expression: A gene expression profiling study with implications for potential combination therapies

The Hodgkin cells and Reed-Sternberg cells (HRS) of classical Hodgkin lymphoma (CHL) are derived from germinal center B cells. The pathogenesis of CHL is unclear but constitutive activation of NFkappaB may contribute. Proteasome inhibition aimed at inhibiting NFkappaB has been shown to result in apoptosis in HRS cells. Here we investigated the effects of bortezomib, a proteasome inhibitor, in HRS cells with a combination of functional assays and gene expression profiling (GEP). Exposure of KMH2 and L428 cells to bortezomib resulted in inhibition of proliferation and induction of apoptosis. Gene expression analysis of KMH2 cells by oligonucleotide cDNA microarrays showed that a limited set of genes were differentially expressed involving several key cellular pathways including cell cycle and apoptosis. Among them, the caspase 8 inhibitor cFLIP was down-regulated and confirmed by Q-PCR. Given the evidence that cFLIP in HRS cells contribute to cells' insensitive to death receptor-mediated apoptosis, we combined bortezomib and TRAIL. This combination caused further down-regulation of cFLIP protein and increased apoptosis in CHL cells demonstrated by PARP p85 immunohistochemistry and immunoblotting. Such apoptotic effects were inhibited by caspase inhibitor z-VAD-FMK, confirming the pro-apoptotic effects of bortezomib and TRAIL are caspase-dependent. Bortezomib has no detectable effect on expression of TRAIL receptor DR4/DR5 in these two cell lines. Tissue microarray analysis of primary Hodgkin lymphomas displayed that 82% cases (95/116) expressed cFLIP in Reed-Sternberg cells. The discovery of apoptotic pathways that can be manipulated by proteasome inhibition provides rationale for the combination of bortezomib and agents such as TRAIL in CHL treatment.

Persistent replication of human immunodeficiency virus type 1 despite treatment of pulmonary tuberculosis in dually infected subjects

Tuberculosis (TB) is the most common life-threatening infection in human immunodeficiency virus (HIV)-infected persons and frequently occurs before the onset of severe immunodeficiency. Development of TB is associated with increased HIV type 1 (HIV-1) viral load, a fall in CD4 lymphocyte counts, and increased mortality. The aim of this study was to examine how treatment of pulmonary TB affected HIV-1 activity in HIV-1/TB-coinfected subjects with CD4 cell counts of >100 cells/mul. HIV-1/TB-coinfected subjects were recruited in Kampala, Uganda, and were monitored over time. Based upon a significant (0.5 log10 copies/ml) decrease in viral load by the end of treatment, two patient groups could be distinguished. Responders (n = 17) had more rapid resolution of anemia and pulmonary lesions on chest radiography during TB treatment. This group had a significant increase in viral load to levels not different from those at baseline 6 months after completion of TB treatment. HIV-1 viral load in nonresponders (n = 10) with TB treatment increased and at the 6 month follow-up was significantly higher than that at the time of diagnosis of TB. Compared to baseline levels, serum markers of macrophage activation including soluble CD14 decreased significantly by the end of TB treatment in responders but not in nonresponders. These data further define the impact of pulmonary TB on HIV-1 disease. HIV-1 replication during dual HIV-1/TB infection is not amenable to virologic control by treatment of TB alone. Concurrent institution of highly active antiretroviral treatment needs to be evaluated in patients dually infected with pulmonary TB and HIV-1.

JC virus chromogenic in situ hybridization in brain biopsies from patients with and without PML

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyoma virus. Electron microscopy and immunohistochemistry are the traditional methods of confirming the presence of the virus in brain biopsies from these patients. We studied the brain biopsies from 7 patients with PML and 6 patients without PML with chromogenic in situ hybridization (CISH) for the JC polyoma virus using a commercially available probe. The biopsies from the patients with the PML cases were proven to contain the JC polyoma virus by traditional and molecular methods. The CISH findings were compared with the known state of infection. All (7/7) of the biopsies from patients with PML were positive for the presence of polyoma virus by CISH, whereas the biopsies from patients without PML were uniformly negative. CISH seems to be a useful tool for the detection of the JC virus in brain biopsies from patients with PML, and is more accessible because a commercial probe is available.

Multilaboratory comparison of hepatitis C virus viral load assays

We report a multilaboratory evaluation of hepatitis C virus (HCV) viral load assays to determine their linear range, reproducibility, subtype detection, and agreement. A panel of HCV RNA samples ranging in nominal concentration from 1.0 to 7.0 log10 IU/ml was constructed by diluting a clinical specimen (genotype 1b). Replicates of the panel were tested in multiple laboratories using the Abbott TaqMan analyte-specific reagent (Abbott reverse transcription-PCR [RT-PCR]), Roche TaqMan RUO (Roche RT-PCR), Roche Amplicor Monitor HCV 2.0 (Roche Monitor), and Bayer VERSANT HCV RNA 3.0 (Bayer bDNA) assays. Bayer bDNA-negative specimens were tested reflexively using the Bayer VERSANT HCV RNA qualitative assay (Bayer TMA). Abbott RT-PCR and Roche RT-PCR detected all 28 replicates with a concentration of 1.0 log10 IU/ml and were linear to 7.0 log10 IU/ml. Roche Monitor and Bayer bDNA detected 27 out of 28 and 13 out of 28 replicates, respectively, of 3.0 log10 IU/ml. Bayer TMA detected all seven replicates with 1.0 log10 IU/ml. Bayer bDNA was the most reproducible of the four assays. The mean viral load values for panel members in the linear ranges of the assays were within 0.5 log10 for the different tests. Eighty-nine clinical specimens of various genotypes (1 through 4) were tested in the Bayer bDNA, Abbott RT-PCR, and Roche RT-PCR assays. For Abbott RT-PCR, mean viral load values were 0.61 to 0.96 log10 greater than the values for Bayer bDNA assay for samples with genotype 1, 2, or 3 samples and 0.08 log10 greater for genotype 4 specimens. The Roche RT-PCR assay gave mean viral load values that were 0.28 to 0.82 log10 greater than those obtained with the Bayer bDNA assay for genotype 1, 2, and 3 samples. However, for genotype 4 samples the mean viral load value obtained with the Roche RT-PCR assay was, on average, 0.15 log10 lower than that of the Bayer bDNA. Based on these data, we conclude that the sensitivity and linear range of the Abbott and Roche RT-PCR assays enable them to be used for HCV diagnostics and therapeutic monitoring. However, the differences in the viral load values obtained with the different assays underscore the importance of using one assay when monitoring response to therapy.

Fatal West Nile Virus infection after rituximab/fludarabine--induced remission for non-Hodgkin's lymphoma

West Nile virus (WNV) infections are potentially life threatening in immunocompromised hosts. Currently, the best diagnostic test is serology. Reverse-transcriptase polymerase chain reaction (RT-PCR) testing has a role, but, because WNV is a cell-associated neurotropic virus, RT-PCR results are frequently negative even in cases of active infection. We present a case in which serology results were persistently negative because the patient was immunocompromised following lymphoma treatment. The role of humoral immunity in resolution of WNV is also discussed.

Multiplexed particle-based anti-granulocyte macrophage colony stimulating factor assay used as pulmonary diagnostic test

Pulmonary alveolar proteinosis (PAP) is characterized by the accumulation of lipoproteinaceous material within the lung alveoli. Recent studies indicate that PAP is an autoimmune disease characterized by a neutralizing anti-granulocyte macrophage colony stimulating factor (GM-CSF) antibody. At present the only definitive diagnostic test for PAP is open lung biopsy. We have previously published that anti-GM-CSF is diagnostic for PAP and correlates with disease pathogenesis using a traditional serial anti-GM-CSF antibody titer format (T. L. Bonfield, M. S. Kavuru, and M. J. Thomassen, Clin. Immunol. 105:342-350, 2002). Titer analysis is a semiquantitative method, and often subtle changes in antibody titer are not detectable. In this report we present data to support anti-GM-CSF detection by a quantitative highly sensitive multiplexed particle-based assay which has the potential to be a clinical diagnostic test.

Use of leflunomide in an allogeneic bone marrow transplant recipient with refractory cytomegalovirus infection

Ganciclovir-resistant cytomegalovirus (CMV) infection is an emerging problem in transplant recipients. Foscarnet resistance and cidofovir resistance have also been described, but no previous reports have suggested treatment regimens for patients with CMV refractory to all three of these drugs. Leflunomide, an immunosuppressive drug used in rheumatoid arthritis and in rejection in solid-organ transplantation, has been reported to have novel anti-CMV activity. However, its clinical utility in CMV treatment has not been described previously. We report an allogeneic bone marrow transplant recipient who developed CMV infection refractory to sequential therapy with ganciclovir, foscarnet, and cidofovir. The patient was ultimately treated with a combination of leflunomide and foscarnet. Both phenotypic and genotypic virologic analysis was performed on sequential CMV isolates. The patient's high CMV-DNA viral load became undetectable on leflunomide and foscarnet, but the patient, who had severe graft-versus-host disease (GVHD) of the liver, expired with progressive liver failure and other complications. We concluded that leflunomide is a new immunosuppressive agent with anti-CMV activity, which may be useful in the treatment of multiresistant CMV. However, the toxicity profile of leflunomide in patients with underlying GVHD remains to be defined.

New cervical cancer screening strategy: combined Pap and HPV testing

Our strategy for cervical cancer screeing is being revolutionized by our new understanding of how human papillomavirus (HPV) contributes to carcinogenesis and the natural history of cervical cancer. The American Cancer Society and the American College of Obstetricians and Gynecologists now recommend combined HPV and Papanicolaou (Pap) testing for cervical cancer screening in women age 30 or older. However, although incorporation of HPV DNA testing into primary screening provides clear benefits, it also raises new questions.

BK and JC polyomaviruses are not associated with idiopathic pulmonary fibrosis

We sought to determine if the BK and JC polyomaviruses were associated with idiopathic pulmonary fibrosis (IPF). We did not detect the BK or JC polyomaviruses in lung tissue extracts from 33 patients with IPF by using real-time PCR, which suggests that an etiologic association is unlikely.

Clinical utility of cytomegalovirus viral load in bronchoalveolar lavage in lung transplant recipients

The utility of cytomegalovirus (CMV) viral load (VL) by quantitative hybrid capture assay (Q-HCA) was investigated in bronchoalveolar lavage (BAL) from lung transplant recipients and compared with BAL cultures and blood VL. Forty-three consecutive BAL samples from 27 lung transplant recipients were analyzed. All samples had shell vial (SV) cultures in addition to Q-HCA. Histopathology was done on all lung tissues, and immunohistochemistry (IHC) in those with positive CMV cultures. Fifteen (56%) lung transplant recipients had both positive BAL SV cultures and BAL VL. Five of 15 had CMV pneumonitis with a VL in BAL >500 000 copies/mL (mean: 1638 450). Ten patients without CMV pneumonitis had VL in BAL <500 000 copies/mL (mean 81 820, p = 0.002). High VL in BAL and blood invariably meant CMV pneumonitis, but 2 patients with CMV pneumonitis had high BAL VL but relatively low blood VL. Initial CMV seronegativity was associated with pneumonitis (4/5 vs. 1/10; p = 0.004) and higher BAL CMV VL (p = 0.03). High CMV BAL or blood VL did not correlate with acute rejection or development of bronchiolitis obliterans syndrome (BOS). High CMV VL in BAL in lung transplant recipients is strongly associated with CMV pneumonitis, and may be more predictive than peripheral blood viral load.

Comparison of five methods for extraction of Legionella pneumophila from respiratory specimens

The efficiencies of five commercially available nucleic acid extraction methods were evaluated for the recovery of a standardized inoculum of Legionella pneumophila in respiratory specimens (sputum and bronchoalveolar lavage [BAL] specimens). The concentrations of Legionella DNA recovered from sputa with the automated MagNA Pure (526,200 CFU/ml) and NucliSens (171,800 CFU/ml) extractors were greater than those recovered with the manual methods (i.e., Roche High Pure kit [133,900 CFU/ml], QIAamp DNA Mini kit [46,380 CFU/ml], and ViralXpress kit [13,635 CFU/ml]). The rank order was the same for extracts from BAL specimens, except that for this specimen type the QIAamp DNA Mini kit recovered more than the Roche High Pure kit.

Detection of hepatitis C virus by a user-developed reverse transcriptase-PCR and use of amplification products for subsequent genotyping

BACKGROUND

Detection, quantitation and genotyping of hepatitis C virus (HCV) are important in selecting appropriate therapy. Current commercially available HCV genotyping kits, including sequencing-based TRUGENE HCV 5'NC and hybridization-based INNO-LiPA HCV II assays, rely on amplification products (amplicons) generated by HCV reverse-transcriptase (RT)-PCR methods such as the Roche AMPLICOR HCV test.

METHODS

We developed a one-step RT-PCR assay to amplify and detect HCV RNA, and the resulting amplicons were used for HCV genotyping (TRUGENE). A total of 142 clinical samples were used to compare results from the RT-PCR/TRUGENE assay and those generated by the COBAS AMPLICOR and INNO-LiPA tests.

RESULTS

Eighty-seven of 108 plasma specimens which were positive by AMPLICOR were also positive by the user-developed RT-PCR, giving a sensitivity of 100.0%. The RT-PCR detected 2 of 21 AMPLICOR-negative specimens and none of 34 HCV-EIA-negative serum specimens, giving a specificity of 96.4%. The 87 amplicons from the RT-PCR yielded HCV genotypes. HCV genotype results from both TRUGENE and INNO-LiPA were all in agreement. The TRUGENE and INNO-LiPA assays identified 69 (79.3%) and 47 (54.0%) specimens, respectively at the subtype level. HCV subtype information agreed by both assays in 34 of 36 (99.4%) specimens. One specimen with HCV genotypes 2 and 4 by INNO-LiPA was classified as a single genotype 2 by TRUGENE.

CONCLUSION

Our data showed that the user-developed RT-PCR has comparable sensitivity and specificity for the detection of HCV in clinical specimens. The amplicons generated by the RT-PCR can be used for HCV genotyping by the sequencing-based TRUGENE assay.

Detection of polyoma virus in brain tissue of patients with progressive multifocal leukoencephalopathy by real-time PCR and pyrosequencing

We evaluated 2 methods, a LightCycler PCR assay and pyrosequencing for the detection of the JC polyoma virus (JCV) in fixed brain tissue of 10 patients with and 3 control patients without progressive multifocal leukoencephalopathy (PML). Nucleic acid extraction was performed after deparaffinization and proteinase K digestion. The LightCycler assay differentiates the BK virus (BKV), JCV, and SV40 using melt curve analysis. Conventional PCR was used with the same primers to generate products for pyrosequencing. Two sequencing primers were used that differentiate the polyoma viruses. Seven of 11 biopsies (1 patient had 2 biopsies) with PML were positive for JCV by real-time PCR and/or PCR/pyrosequencing. Three of 4 remaining biopsies were positive by real-time PCR but had melting points between JCV and SV40. The 4 specimens that were negative or atypical by LightCycler PCR were positive by traditional PCR, but 1 had an amplicon of lower molecular weight by gel electrophoresis. These were shown to represent JCV by at least 1 of the 2 pyrosequencing primers. The biopsies from patients without PML were PCR negative. Both the LightCycler and pyrosequencing assays are useful for confirming JCV in brain biopsies from patients with PML, but variant JCVs may require supplementary methods to confirm JCV infection.

Correlation between viral loads of cytomegalovirus in blood and bronchoalveolar lavage specimens from lung transplant recipients determined by histology and immunohistochemistry

Cytomegalovirus (CMV) is an important pathogen in lung transplant recipients. Early detection of CMV end-organ disease should help with treatment management. We determined the CMV viral load by hybrid capture in bronchoalveolar lavage (BAL) fluid samples from patients who had undergone lung transplantation. For 39 of these samples (from 25 patients), corresponding transbronchial biopsy samples were available for CMV immunohistochemistry (IHC). The CMV IHC results were interpreted and categorized as positive or negative, and the positive results were subcategorized as typical if cells with both significant nuclear enlargement or Cowdry A-type inclusions and positive staining were present or as atypical if definitive nuclear staining was seen but significant nuclear enlargement was not. Diagnostic CMV viral inclusions were reported in the anatomic diagnosis, based on hematoxylin-eosin staining alone, for three (8%) of the biopsy samples. CMV was detected by IHC in 13 (33%) samples (5 typical, 8 atypical). The median CMV viral load in BAL samples was 0 copies/ml for BAL samples from patients with IHC-negative biopsy samples; 47,678 copies/ml for BAL samples from patients with biopsy samples with positive, atypical staining; and 1,548,827 copies/ml for BAL samples from patients with biopsy samples with positive, typical staining (P < 0.001). Compared to routine pathology of biopsy samples, the use of IHC increased the diagnostic yield of CMV. Also, the CMV viral load in BAL fluid samples increased along with immunoreactivity from negative to positive, atypical staining to positive, typical staining. The CMV viral load determined with the end-organ sample, the BAL fluid sample, was higher than the corresponding viral load determined with blood. Both IHC and determination of the CMV viral load in BAL samples may be useful for the detection of individuals at risk for the development of fulminant invasive CMV disease.

Pharmacokinetic Evaluation and Short-Term Activity of Stavudine, Nevirapine, and Nelfinavir Therapy in HIV-1???Infected Adults

OBJECTIVE

Evaluate pharmacokinetic interaction, short-term safety, and antiretroviral activity of stavudine (d4T), nevirapine (NVP), and nelfinavir (NFV) as combination HIV-1 therapy.

DESIGN

Prospective, open-label study investigating the pharmacokinetic interactions between d4T, NVP, and NFV and documenting short-term tolerability and virologic and immunologic activity.

METHODS

Twenty-five HIV-1-infected adults, naive to nonnucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs), < or = 6 months of d4T treatment, CD4 > or = 100 cells/mm, and viral load > = 5,000 copies/mL enrolled. All received NFV 750 mg 3 times daily and d4T 30-40 mg twice daily for 1 week, then added NVP at 200 mg once daily for 2 weeks and 200 mg twice daily thereafter. Steady-state pharmacokinetic parameters of NFV, AG1402 (metabolite of NFV), and d4T were compared before and after the addition of NVP.

RESULTS

No statistically significant changes in NFV or d4T pharmacokinetics were observed following the addition of NVP. Levels of AG1402 were suppressed 60-70%. Drug-related adverse events were seen at expected rates. At day 36, median viral load suppression was 2.0 log10 and absolute CD4 count increased by 111 cells/mm.

CONCLUSIONS

NVP administration did not significantly affect the steady-state pharmacokinetic parameters of NFV or d4T. The combination of d4T, NVP, and NFV induced rapid suppression of HIV-1 viral load and rises in CD4 cell count.