Real-World Effectiveness of Dolutegravir/Lamivudine in People With HIV-1 in Test-and-Treat Settings or With High Baseline Viral Loads: TANDEM Study Subgroup Analyses

INTRODUCTION

Dolutegravir/lamivudine (DTG/3TC) was first approved by the US Food and Drug Administration in 2019 for the treatment of antiretroviral therapy (ART)-naive people with HIV-1 based on results from the pivotal GEMINI-1/GEMINI-2 trials. Around that time, immediate initiation of treatment upon diagnosis was recommended in the US Department of Health and Human Services guidelines. Here we report results from 126 treatment-naive people with HIV-1 who initiated DTG/3TC as part of a test-and-treat strategy (n = 61) or with high baseline viral loads (HIV-1 RNA ≥ 100,000 copies/ml; n = 16) from the TANDEM study.

METHODS

TANDEM was a US-based, retrospective chart review study that included a cohort of 126 individuals aged ≥ 18 years with no prior history of ART who initiated DTG/3TC before September 30, 2020, and had ≥ 6 months of follow-up. Test-and-treat was defined as ART initiation shortly after diagnosis without available viral load, CD4 + cell count, or HIV-1 resistance data. Outcomes included virologic suppression (HIV-1 RNA < 50 copies/ml; overall and by baseline viral load) and discontinuations. Analyses were descriptive.

RESULTS

Among 61 individuals who initiated DTG/3TC in a test-and-treat setting (median [interquartile range (IQR)] treatment duration, 1.3 [0.9-1.7] years), 57 (93%) achieved virologic suppression, and 51 (84%) remained suppressed; 1 (< 1%) individual discontinued DTG/3TC due to persistent low-level viremia. The most common healthcare provider (HCP)-reported reason for initiating DTG/3TC was avoidance of long-term toxicities among individuals in the test-and-treat subgroup. Of 16 treatment-naive individuals with high baseline viral loads (median [IQR] treatment duration, 100,000-250,000 copies/ml: 1.2 [0.8-1.8] years; > 250,000 copies/ml: 1.0 [0.7-1.1] years), 14 (88%) achieved virologic suppression, 13 (81%) remained suppressed, and none discontinued DTG/3TC. Patient preference was the most common HCP-reported reason for initiating DTG/3TC in this subgroup.

CONCLUSIONS

Results demonstrate real-world effectiveness of DTG/3TC, with few discontinuations, in people with HIV-1 in test-and-treat settings or with high baseline viral loads.

Two-Drug Regimens Dolutegravir/Lamivudine and Dolutegravir/Rilpivirine Are Effective with Few Discontinuations in US Real-World Settings: Results from the TANDEM Study

INTRODUCTION

Dolutegravir/lamivudine (DTG/3TC) and dolutegravir/rilpivirine (DTG/RPV) are fixed-dose, complete, single-tablet, two-drug regimens (2DRs) indicated for HIV-1. DTG/3TC is approved for antiretroviral therapy (ART)-naive people with HIV-1 and virologically suppressed individuals to replace current ART; DTG/RPV is indicated for virologically suppressed individuals as a switch option. Virologic efficacy and effectiveness of these DTG-based 2DRs have been demonstrated in phase 3 clinical trials and real-world cohorts, primarily from Europe. This study characterized real-world use of DTG-based 2DRs for HIV-1 treatment in the USA.

METHODS

TANDEM was a retrospective medical chart review across 24 US sites. Individuals aged ≥ 18 years who initiated DTG/3TC or DTG/RPV before September 30, 2020, with ≥ 6 months of follow-up were included. One cohort included ART-naive people who initiated DTG/3TC (n = 126), and two other cohorts included virologically suppressed (HIV-1 RNA < 50 copies/mL) people on stable ART regimens for ≥ 3 months before switch to either DTG/3TC (n = 192) or DTG/RPV (n = 151). Clinical characteristics, treatment history, and outcomes are described.

RESULTS

Virologically suppressed individuals were older than those who were ART-naive, and the ART-naive cohort had higher proportions of individuals assigned male at birth and of Hispanic ethnicity. The most common healthcare provider-reported reason for choosing a DTG-based 2DR was avoidance of long-term toxicities (25-33% across cohorts), followed by simplification/streamlining of treatment. Among ART-naive people on DTG/3TC, 94% achieved virologic suppression after initiation, and 83% maintained suppression at last follow-up; discontinuation rate was < 1%. Among cohorts who switched to DTG-based 2DRs, 96% maintained virologic suppression on DTG/3TC and 93% on DTG/RPV; 2% on DTG/3TC and 3% on DTG/RPV discontinued.

CONCLUSION

Motivation for selecting DTG-based 2DRs was primarily driven by a desire to avoid or manage toxicities and simplify treatment. Results demonstrate that DTG/3TC and DTG/RPV are effective in real-world settings, with few discontinuations, reflecting data from clinical trials.

Sustained Virologic Suppression With Dolutegravir/Lamivudine in a Test-and-Treat Setting Through 48 Weeks

Background

We assessed efficacy and safety of dolutegravir/lamivudine (DTG/3TC) in a US test-and-treat setting at the secondary 48-week time point of the multicenter, single-arm, phase IIIb STAT study.

Methods

Eligible adults newly diagnosed with HIV-1 started once-daily DTG/3TC within 14 days of diagnosis, before availability of laboratory results. Antiretroviral therapy (ART) was modified if baseline testing indicated DTG or 3TC resistance, hepatitis B virus (HBV) co-infection, or creatinine clearance &lt;30 mL/min/1.73 m2 and these participants remained on study. Proportion with HIV-1 RNA &lt;50 copies/mL at Week 48 was calculated among all participants (intention-to-treat–exposed [ITT-E] missing = failure analysis) and those with available data (observed analysis).

Results

At Week 48, 82% of all participants regardless of ART (107/131; ITT-E missing = failure) and 97% with available data (107/110; observed analysis) achieved HIV-1 RNA &lt;50 copies/mL. High proportions of virologic response were seen overall, including in participants with high viral load (≥500,000 copies/mL; 89%) or low CD4+ cell count (&lt;200 cells/mm3; 78%) at baseline. Ten participants had treatment modification (baseline HBV co-infection, n=5; participant/proxy decision, n=2; baseline M184V resistance mutation, adverse event [AE; rash], and pregnancy, n=1 each) before Week 48. Two participants met confirmed virologic failure (CVF) criteria. No treatment-emergent resistance was observed. Ten participants reported drug-related AEs (all grade 1-2); no serious drug-related AEs occurred.

Conclusions

Results demonstrated high proportions of participants with sustained virologic suppression, no treatment-emergent resistance, and good safety over 48 weeks, supporting first-line use of DTG/3TC in a test-and-treat setting.

1288. US Healthcare Provider Perspectives on the initiation of cabotegravir and rilpivirine long-acting (CAB+RPV LA) in an observational real-world study (BEYOND)

Background

CAB+RPV LA is a complete regimen for treatment of virologically suppressed people with HIV (PWH). As an injectable therapeutic administered by a healthcare provider (HCP), CAB+RPV LA may alleviate challenges with adherence to daily oral therapy and reduce fear of HIV status disclosure with oral treatment. Real world perspectives from HCPs and PWH are needed to enable successful delivery of this treatment in US healthcare settings.

Methods

BEYOND is a 2 year prospective, observational, real-world study of utilization, outcomes, and experience of PWH initiating CAB+RPV LA across 30 US sites. HCPs at participating sites (treaters, injectors, drug acquisition/reimbursement staff) completed surveys at site activation (Sep 2021-Feb 2022; with follow-up surveys planned at 6, 12, 24 months) evaluating experiences to date with implementation of CAB+RPV LA at their sites.

Results

HCPs from 24 sites responded to the initial survey (Table 1). 75% of HCPs estimated that ≥25% of their PWH are eligible for CAB+RPV LA, and 71% of sites are proactively discussing the regimen with ≥25% of PWH. The majority (79%) of treaters reported they were extremely/very positive about administering CAB+RPV LA. Over 90% of injectors reported a positive overall opinion about administering CAB+RPV LA, and 86% reported the injections were easy to administer. Most (87%) HCPs reported injection visits taking ≤45 minutes, including waiting time. Over 95% of sites have patient reminder systems; 86% will manually identify missed injections and all reported manual follow up by site staff. All sites utilizing the injection education video on the external HCP website (n=15/15) found it helpful and 94% (n=16/17) utilizing reimbursement specialists found them to be helpful. In their experience to date, most clinics reported only needing to increase coordination with the pharmacy team and add injection training to implement CAB+RPV LA. The most frequently reported benefits of implementing CAB+RPV LA by HCPs included assurance of patient adherence and patient engagement in their HIV treatment (Table 2).

Conclusion

Early real-world data from US HCPs in this study indicates interest in and anticipated uptake of CAB+RPV LA at their sites, positive overall opinion, and multiple benefits of administering the CAB+RPV LA regimen to PWH.

Disclosures

Ricky K. Hsu, MD, Gilead: Honoraria|Merck: Honoraria|ViiV: Advisor/Consultant|ViiV: Grant/Research Support|ViiV: Honoraria John Phoenix, MSN, APRN, FNP-C, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Honoraria|Gilead Sciences: speaker bureau, research funding|Janssen Pharmaceutical: Advisor/Consultant|Janssen Pharmaceutical: Honoraria|Lupin Pharmaceuticals: Advisor/Consultant|Lupin Pharmaceuticals: Honoraria|Napo pharmaceutical: Honoraria|Napo pharmaceutical: speaker bureau|Scinexis: Advisor/Consultant|Scinexis: Honoraria|ViiV Healthcare: Advisor/Consultant|ViiV Healthcare: Honoraria|ViiV Healthcare: speaker bureau, clinical research funding Gary I. Sinclair, MD, ABBVIE: Grant/Research Support|Gilead: Grant/Research Support|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Janssen: Honoraria|Merck: Grant/Research Support|Thera: Grant/Research Support|Thera: Honoraria|ViiV/GSK: Advisor/Consultant|ViiV/GSK: Grant/Research Support|ViiV/GSK: Honoraria Samir K. Gupta, MD, Gilead Sciences: Advisor/Consultant|GSK/ViiV: Advisor/Consultant|GSK/ViiV: Grant/Research Support Ana Puga, MD, FAAP, AAHIVS, Care Resource: Healthcare provider (HCP)|ViiV Healthcare: Stocks/Bonds Kaitlin Nguyen, PharmD, AAHIVE, ViiV Healthcare: Stocks/Bonds Catherine K. Schubert, PharmD, ViiV Healthcare: Stocks/Bonds Deanna Merrill, PharmD, MBA, AAHIVP, ViiV Healthcare: Salaried employee|ViiV Healthcare: Stocks/Bonds David Richardson, BA, ViiV Healthcare: ViiV provided funding to RTI for the development of the study materials, the conduct of the study, and analysis & interpretation of study results. Kate Nelson, M.Ed, ViIV: ViiV provided funding to RTI for the development of the study materials, the conduct of the study, and analysis & interpretation of study results. Maria Reynolds, MStat, ViiV Healthcare: Viiv provided funding to RTI for the development of the study materials, the conduct of the study, and analysis & interpretation of study results. Laurie Zografos, BS, Viiv: ViiV provided funding to RTI for the development of the study materials, the conduct of the study, and analysis & interpretation of study results. Ashley Jean-Louis, MPH, ViiV Healthcare: (ViiV provided funding to RTI for the development of the study materials, the conduct of the study, and analysis & interpretation of study results.) Cindy Garris, MS, ViiV Healthcare: Employee|ViiV Healthcare: Stocks/Bonds.

1278. Real World Treatment Experience of Single Tablet Dolutegravir/Lamivudine in Those Naïve to Treatment with Baseline Viral Loads ≥ 100,000 copies/mL in the US

Background

Treatment for people living with HIV-1 (PLWH) continues to advance with a two-drug regimen (2DR) approach. Dolutegravir/lamivudine (DTG/3TC) is indicated as a 2DR for both treatment-naïve and virally suppressed PLWH. Despite high and sustained virologic efficacy for DTG-based 2DRs observed in clinical trials, there is limited evidence in US real world clinical settings. This study characterizes prescribing behaviors and treatment outcomes for DTG-based 2DR in the real world.

Methods

TANDEM was a retrospective medical chart review conducted across 24 US sites. Eligible PLWH were adults initiated on single tablet DTG/3TC or DTG/rilpivirine prior to Sept/30/2020 with a minimum clinical follow-up of six months. Treatment-naïve PLWH had no prior history of HIV therapy. Clinical characteristics, treatment history and outcomes were abstracted. Analyses were descriptive. Reported here are viral outcomes for the DTG/3TC cohort of treatment-naïve PLWH with baseline viral loads (VLs) ≥ 100,000 (c/mL).

Results

From an overall sample of 469 PLWH on DTG-based 2DR, 318 received DTG/3TC. Of the DTG/3TC cohort, 126 were treatment-naïve. Of the treatment-naïve, 58 PLWH had known VLs available at DTG/3TC initiation. For those with baseline VLs ≥ 100,000 c/mL, 9 had values 100,000-250,000 c/mL while 7 were > 250,000 c/mL. Characteristics of this sub-cohort are described in Table 1. Overall, the most common reason for DTG/3TC initiation in this sub-cohort was patient preference (n=5), followed by avoidance of long-term toxicities and convenience (both n=3). For those with VLs between 100-250k, median CD4 count was 312 while 8/9 became virally suppressed (HIV-1 RNA < 50c/mL) and 1 PLWH had missing data. For those with VLs > 250k, median CD4 count was 114 while 6/7 became virally suppressed and 1 PLWH had missing data. One of these 6 PLWH experienced virologic rebound yet remained on DTG/3TC. Table 1:

1279. Real World Treatment Experience of Treatment-Naïve People with HIV who Initiated Treatment with Single Tablet Dolutegravir/Lamivudine in a Test and Treat setting in the US

Background

Dolutegravir/lamivudine (DTG/3TC) is indicated as a 2DR for both treatment-naïve and virally suppressed PLWH. The feasibility of DTG/3TC use in a Test & Treat (T&T) setting has been demonstrated in a clinical trial, but there is limited evidence with this approach in US real world clinical settings.

Methods

TANDEM was a retrospective medical chart review conducted across 24 US sites. Eligible PLWH were adults initiated on DTG/3TC or DTG/rilpivirine (DTG/RPV) prior to Sept/30/2020 with a minimum clinical follow-up of six months. Treatment-naïve (TN) PLWH had no prior history of HIV therapy. Clinical characteristics, treatment history and outcomes were abstracted. Analyses were descriptive. Reported here are results for the sub-group of TN PLWH that were initiated DTG/3TC as part of a T&T strategy, defined as clinician attestation of treatment initiation shortly after diagnosis and in the absence of known lab values for HIV-1 RNA viral load, CD4 cell count and HIV-1 resistance mutations.

Results

From an overall sample of 469 PLWH on DTG-based 2DR, 318 received DTG/3TC, of whom, 126 were TN and 192 were stable switch. Almost half 48% of PLWH received DTG/3TC as part of a T&T paradigm. Characteristics of the cohort are described in Table 1. In the T&T sub-group, the most common reasons for initiating DTG/3TC were avoidance of long-term toxicities (n=26), followed by simplification/streamlining (n=8) and convenience (n=7). Overall, 114 (90.5%) of TN PLWH achieved the desired health outcome per clinician attestation. At data cut-off, 61 (94%) non T&T achieved virologic suppression, 57 (93%) of the T&T sub-group achieved virological suppression, 3 (5%) did not, and 1 (2%) was still unknown. Of the 3 who did not achieve suppression, 2 remained on DTG/3TC while 1 was switched to bictegravir/emtricitabine/tenofovir alafenamide. Virologic rebound occurred in 6 TN PLWH overall with only 1 occurring in the T&T sub-group.

Baseline Characteristics and Virologic Outcomes

Conclusion

Reflecting results from clinical trials, DTG/3TC achieved its desired health outcomes in the majority of cases regardless of treatment paradigm, with virtually no difference in virological suppression rates across the two cohorts (93-94% achieving suppression in a median duration of 10-11 weeks).

Disclosures

Cindy Donovan, PharmD, Johnson & Johnson: Stocks/Bonds|ViiV Healthcare: Employee/Salary|ViiV Healthcare: Stocks/Bonds Gavin Harper, BA, ViiV Healthcare: Adelphi Real World were paid consultants (CRO) to conduct the observational research study on behalf of ViiV Healthcare.|ViiV Healthcare: Adelphi Real World were paid consultants (CRO) to conduct the observational research study on behalf of ViiV Healthcare Deanna Merrill, PharmD, MBA, AAHIVP, ViiV Healthcare: Salaried employee|ViiV Healthcare: Stocks/Bonds Katie L. Mycock, MChem, ViiV Healthcare: Adelphi Real World were paid consultants (CRO) to conduct the observational research study on behalf of ViiV Healthcare|ViiV Healthcare: Adelphi Real World were paid consultants (CRO) to conduct the observational research study on behalf of ViiV Healthcare Alan Oglesby, MPH, GlaxoSmithKline (GSK): Employment|GlaxoSmithKline (GSK): Stocks/Bonds Aimee Metzner, PharmD, AAHIVP, ViiV Healthcare: Salaried employee|ViiV Healthcare: Stocks/Bonds Jimena Patarroyo, PharmD, AAHIVP, ViiV Healthcare: Salaried employee|ViiV Healthcare: Stocks/Bonds|ViiV Healthcare: Stocks/Bonds.

Perspectives of people living with HIV-1 on implementation of long-acting cabotegravir plus rilpivirine in US healthcare settings: results from the CUSTOMIZE hybrid III implementation-effectiveness study

INTRODUCTION

The CUSTOMIZE hybrid III implementation-effectiveness study evaluated implementation of once-monthly long-acting (LA) cabotegravir + rilpivirine in diverse US healthcare settings. Here, we report patient participant perspectives after 12 months in CUSTOMIZE.

METHODS

CUSTOMIZE was a phase IIIb, 12-month study conducted from July 2019 to October 2020 at eight diverse US HIV clinics that enrolled virologically suppressed people living with HIV-1 (PLHIV) on a stable oral regimen to receive monthly cabotegravir + rilpivirine LA injections after a 1-month oral lead-in. Participants were administered quantitative surveys before injections at months 1 (baseline), 4 and 12. A randomly selected subset of participants was interviewed at baseline and month 12. Data collection at month 12 was completed by October 2020 (during the COVID-19 pandemic).

RESULTS

At baseline, 109 and 34 participants completed surveys and interviews, respectively; 87% were male; 35% were Black or African American. All participants who remained in the study at month 12 (n = 102) maintained HIV-1 RNA <50 copies/ml; two participants withdrew due to injection-related reasons. Mean total scores measuring acceptability and appropriateness of cabotegravir + rilpivirine LA were high at baseline (4.5-4.6 out of 5) and month 12 (4.7-4.9). At month 12, 74% of participants reported nothing interfered with receiving LA injections; injection pain or soreness was the most common concern (15%). Time spent in the clinic and coming to the clinic for monthly injections was very or extremely acceptable after 12 months for most participants (93% and 87%, respectively), with 64% reporting having spent ≤30 minutes in the clinic for injection visits. At month 12, 92% of participants preferred LA injections to daily oral tablets (3%); 97% plan to continue LA treatment going forward. In month 12 interviews, 24 (77%) of 31 participants reported the COVID-19 pandemic did not impact their ability to receive treatment.

CONCLUSIONS

Once-monthly cabotegravir + rilpivirine LA was highly acceptable among PLHIV who were virologically suppressed on a stable antiretroviral regimen and interested in trying LA therapy, with few participants reporting challenges receiving LA injections. Implementation data from CUSTOMIZE suggest that monthly LA injections provide a convenient and appealing treatment option for PLHIV.

Perspectives of healthcare providers on implementation of long-acting cabotegravir plus rilpivirine in US healthcare settings from a Hybrid III Implementation-effectiveness study (CUSTOMIZE)

Introduction

CUSTOMIZE evaluated the implementation of long‐acting (LA) cabotegravir + rilpivirine, a novel healthcare provider–administered injectable antiretroviral therapy regimen, in diverse US healthcare settings. Findings from staff‐study participants (SSPs) through 12 months of implementation are reported.

Methods

CUSTOMIZE was a phase IIIb, 12‐month, single‐arm, hybrid III implementation‐effectiveness study conducted from July 2019 to October 2020 at eight US clinics of five clinic types: private practice (n = 2), federally qualified health centre (n = 2), university (n = 2), AIDS Healthcare Foundation (n = 2) and health maintenance organization (n = 1). Eligible patient participants received monthly cabotegravir + rilpivirine LA injections after a 1‐month oral lead‐in. At baseline, month 4 and month 12, SSPs (n = 3 each per clinic), including physicians, nurses or injectors, and administrators, completed quantitative surveys and semi‐structured interviews to assess implementation outcomes (acceptability, appropriateness and feasibility of intervention measures), programme sustainability and SSP perceptions of, attitudes towards, and expectations for cabotegravir + rilpivirine LA. Month 12 data collection occurred during the COVID‐19 pandemic.

Results

In surveys, SSPs reported high mean total scores for acceptability, appropriateness and feasibility of cabotegravir + rilpivirine LA implementation at baseline (4.43, 4.52 and 4.38 of 5, respectively) and month 12 (4.45, 4.61 and 4.46 of 5, respectively), regardless of clinic type. At month 12, SSPs were positive about the implementation sustainability (mean Program Sustainability Assessment Tool score, 5.83 out of 7). At baseline, SSPs’ top concern was patients’ ability to maintain monthly appointments (81%); at month 12, 39% had this concern. The proportion of SSPs reporting patient injection pain or soreness as a barrier was consistent at month 12 versus baseline (48% vs. 46%). Most (78%) SSPs reported optimal implementation of cabotegravir + rilpivirine LA in their clinics was achieved in 1–3 months. In interviews, SSP‐reported strategies for successful implementation included teamwork, using a web‐based treatment planner and having a designated person to track appointment scheduling. In month 12 interviews, SSP‐reported structural changes needed for implementation included changing clinic hours and purchasing refrigerators.

Conclusions

In CUSTOMIZE, cabotegravir + rilpivirine LA was successfully implemented across a range of US healthcare settings. Barriers were mitigated with minor process adjustments.

The effect of the microbiome on immune checkpoint inhibitor toxicity in patients with melanoma

9568

Background: Immune-checkpoint inhibitor (ICI) immunotherapy has increased survival in patients with melanoma. However, only half of the patients respond, and many experience immune-related adverse events (irAEs). Recent evidence suggests that modification of the gut microbiome may increase response to ICIs and decrease toxicity. Here we describe the first results of a clinical trial to determine if the microbiome can predict the response or toxicity during the first 16 weeks of ICI treatment. Methods: We enrolled patients aged 18 or older in a prospective observational cohort study at The Ohio State University Comprehensive Cancer Center Skin Cancer Clinic (OSUCCC-SCC) who were to receive treatment with pembrolizumab or nivolumab alone or in combination with other treatments (e.g. nivolumab and ipilimumab) for melanoma. Patients receiving systemic or oral corticosteroids at the start of ICI cycle 1 were excluded but were eligible if receiving adrenal physiologic replacement. Patients collected stool samples at baseline, within 2 days of an adverse event (if applicable), and at 12 weeks. The response to ICIs was evaluated by Response Evaluation Criteria in Solid Tumors (RECIST v1.1) at a 12-week computed tomography scan. Metagenomic whole-genome shotgun sequencing was performed on an Illumina NovaSeq 6000 and then classified using HUMAnN3. The effect of microbe relative abundances on potential irAEs was modeled by logistic regression with the R package glmm. Results: In total, 88 patients consented to the trial. Pre-treatment microbiome samples were collected from 49 patients. Potential irAEs were observed in 16 out of the 49 patients for whom pre-treatment microbiome samples were collected. There was no significant difference in the ages (p = 0.150, genders (p = 0.2), stages (p = 0.2) or treatments (p = 0.07) of those who developed potential irAEs. Pretreatment abundance of the family Ruminococaceae was most strongly associated with the development of a potential irAE (p = 0.03), followed by a taxon in an unclassified order within the phylum Firmicutes (p = 0.05). The family Bacteroidaceae was most strongly associated with no potential irAE (p = 0.05). Conclusions: Longitudinal and event-driven biospecimen collection in the context of treatment with immunotherapies was feasible in the OSUCCC-SCC. The abundance of the two high-taxonomic rank microbe groups was significantly associated with potential irAEs. The association with Ruminococaceae is consistent with previous studies where it was associated with response to ICIs and, in separate studies, development of an irAE was associated with a better response. The unclassified taxon is potentially a new biomarker for the prediction of toxicity and a therapeutic target to reduce treatment side effects. Future analyses will associate microbes with treatment response and test for consistent microbiome changes at the time of irAE development. Clinical trial information: NCT05102773.

75. High Rates of Virologic Suppression with DTG/3TC in Newly Diagnosed Adults with HIV-1 Infection and Baseline Viral Load &gt;500,000 c/mL: 48-Week Subgroup Analysis of the STAT Study

Background

The primary analysis of the STAT study demonstrated the feasibility, efficacy, and safety of using DTG/3TC as a first-line regimen in a test-and-treat setting through 24 weeks, with therapy adjustments for baseline resistance or hepatitis B virus (HBV) co-infection. Here we present secondary analyses through Week 48 of virologic outcomes in participants by baseline viral load (VL).

Methods

STAT is a single-arm study of treatment-naive adults with HIV-1 infection who initiated DTG/3TC ≤ 14 days after HIV-1 diagnosis without availability of screening/baseline laboratory results. If baseline testing indicated DTG or 3TC resistance, HBV co-infection, or creatinine clearance &lt; 30 mL/min/1.73 m2, then antiretroviral therapy (ART) was potentially adjusted and participants remained on study. Efficacy analyses included proportion of participants with HIV-1 RNA &lt; 50 c/mL regardless of ART regimen at Week 48, among all participants (ITT-E missing = failure analysis) and among participants with available HIV-1 RNA data at Week 48 (observed analysis).

Results

Of 131 enrolled, DTG/3TC treatment was adjusted in 10 participants, and of those with available data (n=7), all (100%) achieved HIV-1 RNA &lt; 50 c/mL at Week 48. At Week 48, 82% (107/131) of all participants (Figure 1) and 97% (107/110) of those with available data (Figure 2) achieved HIV-1 RNA &lt; 50 c/mL. Of participants with baseline VL ≥ 500,000 c/mL, 89% (17/19) achieved HIV-1 RNA &lt; 50 c/mL at Week 48; the remaining 2 withdrew from study. Of participants with baseline VL ≥ 1,000,000 c/mL, 90% (9/10) achieved HIV-1 RNA &lt; 50 c/mL at Week 48 (Table); the remaining participant withdrew consent. Of the 17 participants with baseline VL ≥ 500,000 c/mL with available data through Week 48, 76% (13/17) achieved virologic suppression by Week 24. One participant with baseline VL ≥ 500,000 c/mL switched from DTG/3TC before the Week 48 assessment. Of the 9 participants with baseline VL

≥ 1,000,000 c/mL with available data through Week 48, most participants (8/9; 89%) were suppressed by Week 24.

Figure 1. Virologic outcomes at Week 48, overall and by baseline VL and CD4+ cell count: ITT-E missing = failure analysis.

Conclusion

These data provide evidence for the efficacy and feasibility of using DTG/3TC as a first-line regimen in a test-and-treat setting, including among participants with very high baseline VL.

Disclosures

Charlotte-Paige M. Rolle, MD MPH, Gilead Sciences (Grant/Research Support, Scientific Research Study Investigator, Speaker’s Bureau)Janssen Infectious Disease (Scientific Research Study Investigator, Advisor or Review Panel member)ViiV Healthcare (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker's Bureau) Tulika Singh, MD MS AAHIVS, Gilead (Grant/Research Support, Advisor or Review Panel member)ViiV (Grant/Research Support, Advisor or Review Panel member, Speaker's Bureau) Moti Ramgopal, MD FIDSA, Abbvie (Scientific Research Study Investigator, Speaker's Bureau)Gilead (Consultant, Scientific Research Study Investigator, Speaker's Bureau)Janssen (Consultant, Scientific Research Study Investigator, Research Grant or Support, Speaker's Bureau)Merck (Consultant, Scientific Research Study Investigator)ViiV (Consultant, Scientific Research Study Investigator, Speaker's Bureau) Dushyantha Jayaweera, MD, mrcog(uk), face, Gilead (Research Grant or Support)Janssen (Research Grant or Support)viiv (Research Grant or Support) Peter Leone, MD, viiv healthcare (Employee) Jessica Matthews, BS, ViiV Healthcare (Employee) Michael Cupo, Ph.D., GlaxoSmithKline (Employee) Mark Underwood, PhD, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee) Kostas Angelis, PhD, GSK (Employee, Shareholder) Brian Wynne, MD, ViiV Healthcare (Employee, Shareholder, I have shares in GSK, the part owner of ViiV) Deanna Merrill, PharmD, MBA, AAHIVP, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee) Christopher T. Nguyen, MD, ViiV Healthcare (Employee) Jean A. van Wyk, MB,ChB, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee) Andrew Zolopa, MD, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee)

Dolutegravir/lamivudine as a first-line regimen in a test-and-treat setting for newly diagnosed people living with HIV

OBJECTIVES

Dolutegravir/lamivudine (DTG/3TC) is indicated for treatment-naive and experienced people with HIV; however, questions remain about its utility in a test-and-treat setting because of potential transmitted resistance and baseline hepatitis B virus (HBV) co-infection. We present feasibility and efficacy of DTG/3TC in newly diagnosed individuals in a test-and-treat setting.

DESIGN

The single-arm STAT study evaluated DTG/3TC in a US test-and-treat setting.

METHODS

Eligible adults initiated DTG/3TC 14 days or less after HIV-1 diagnosis without availability of baseline laboratory results. If baseline testing indicated DTG or 3TC resistance, HBV co-infection, or creatinine clearance less than 30 ml/min per 1.73 m2, participants remained on study with treatment modification. Efficacy endpoints included proportions of participants with HIV-1 RNA less than 50 copies/ml at Week 24, regardless of antiretroviral regimen, among all participants (intention-to-treat exposed) and those with available HIV-1 RNA data (observed).

RESULTS

Of 131 participants enrolled, 8% were female and 50% were non-white. Through Week 24, treatment was modified in eight participants [five with HBV co-infection, one with baseline M184V, one for adverse event (rash), one participant decision]. At Week 24, 78% (102/131) of all participants and 92% (102/111) of those with available data achieved HIV-1 RNA less than 50 copies/ml. Incidence of drug-related adverse events was low (7%); no drug-related serious adverse events occurred.

CONCLUSION

These data demonstrate the feasibility, efficacy, and safety of using DTG/3TC as a first-line regimen in a test-and-treat setting, with therapy adjustments for baseline resistance or HBV co-infection occurring safely via routine clinical care as needed [ClinicalTrials.gov, NCT03945981; see Supplemental Digital Content 1, video abstract (Video abstract summarizing the STAT study design and results), http://links.lww.com/QAD/C189].

Different expression of placental pyruvate kinase in normal, preeclamptic and intrauterine growth restriction pregnancies

INTRODUCTION

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are two diseases that affect pregnant women and their unborn children. These diseases cause low birth weight, pre-term delivery, and neurological and cardiovascular disorders in babies. Combined they account for 20% of preterm deliveries. Pyruvate kinase M2 (PKM2) is a metabolism enzyme found in developing embryonic and cancer tissues. Our objective is to determine the expression of PKM2 in human PE and IUGR compared to normal pregnancies. Understanding expression of PKM2 in PE and IUGR could help us to better understand the mechanisms and find treatments for PE and IUGR.

METHODS

Human placental tissues were obtained for PKM2 determination and analyzed by immunohistochemistry, Western blot, and a pyruvate assay. Placental samples were homogenized and cytoplasmic and nuclear proteins were extracted for Western blot analysis.

RESULTS

Preeclampsia samples had elevated levels of p-PKM2, p-ERK, and ERK in the cytoplasm. Beta-catenin and lactose dehydrogenase (LDH) were also elevated in preeclampsia placenta samples.

DISCUSSION AND CONCLUSION

We conclude that PKM2 is expressed in normal, PE and IUGR pregnancies. Also, that this expression is increased in the PE placenta at delivery. These results suggest placental metabolism through PKM2 could play a role in human preeclampsia.

Groundwater Iron Assessment and Consumption by Women in Rural Northwestern Bangladesh

In Bangladesh, approximately 97 % of the rural population uses groundwater as a drinking source. In many areas of the country this water is known to have elevated levels of iron. The contribution to iron intake that this exposure provides, and the impact on health, are unknown. In the pre- and post-monsoon seasons of 2008, we measured iron content of household tube well water, explored local water collection methods, and estimated iron intake through consumption of groundwater for 276 women of reproductive age in a rural setting in northwestern Bangladesh. Groundwater samples were analyzed for total iron (mg/L), arsenic (category of µg/L), pH, temperature (oC), and oxidation-reduction potential (Eh). Participants drank [mean (SD); 2.7 (0.8) L] of water per day, all of which was collected from domestic tube wells. Total iron concentration in groundwater was high, [median (IQR) 16.3 (6.9, 28.2) mg/L], and variable throughout the area. Using this value, estimated daily iron intake [median (IQR)] was 41.1 (16.0, 71.0) mg from drinking water alone. The amount of water consumed was unrelated to its iron concentration (r = - 0.06; p = 0.33) despite potentially unpleasant organoleptic qualities of high iron content in water. Groundwater contributes substantially to daily iron intake of rural Bangladeshi women and currently represents an under-assessed potential source of dietary iron.

Percutaneous management of perianastomotic stenosis in arteriovenous fistulae: Results of a prospective study

Surgical creation of new anastomosis has been proposed as the preferred treatment for perianastomotic stenoses of fistulae. However, disadvantages of surgical approach have included (1) frequent conversion of fistula to a graft by using synthetic graft material to create a new anastomosis, (2) shortening the length of the cannulation segment by proximal autologous arteriovenous neoanastomosis, and (3) abandoning the fistula altogether in favor of a synthetic graft. We report the results of a prospective study using percutaneous balloon angioplasty (PTA) to treat fistulae with perianastomotic lesions. Seventy-three consecutive patients undergoing 112 PTA procedures for the treatment of perianastomotic lesions were studied. Primary and secondary patency rates were calculated. Procedure success, procedure-related complications, and conversion of fistulae to grafts were recorded. The initial success rate was 97%. The degree of stenosis before and after PTA was 81 +/- 9 and 11+/-11%, respectively. Primary patency rates at 6, 12, and 18 months were 75, 51, and 41%, respectively. Secondary patency rates at 6, 12, and 18 months were 94, 90, and 90%, respectively. Grade I hematoma occurred in three and vein rupture in two cases. No grafts were inserted. These outcomes are superior to those that have been reported for surgery. The outpatient PTA is safe and effective for the management of perianastomotic stenosis. Because of its advantage of fistula preservation, the percutaneous approach should be considered as the preferred first-line therapy for the management of perianastomotic fistula lesions.

Review of medical encounters in the 5 years before a diagnosis of HIV-1 infection: implications for early detection

Early detection of HIV infection improves prognosis and reduces transmission, but 30%-40% of cases are diagnosed late. A comprehensive and systematic review of medical encounters before diagnosis has not been done. This study reviews 5 years of medical encounters before the diagnosis of HIV infection in members of a large managed care organization where access to care is reasonably good. Patient characteristics, HIV risk factors, and clinical events preceding diagnosis were examined and tested for association with late diagnosis (CD4 cell count of <200/microL at diagnosis). Of 440 HIV-infected patients, 62% had CD4 cell counts of <350/microL, 43% had CD4 cell counts of <200/microL, and 18% had CD4 cell counts of <50/microL at diagnosis. Twenty-six percent of all patients had risks documented >1 year before diagnosis. Only 22% of patients had one of eight clinical indicators suggested in the literature as reasons to test for HIV >1 year before diagnosis. In multiple logistic regression, older age, male sex, race, risk group, no prior HIV testing, physician-initiated testing, and having any of eight clinical indicators before diagnosis were each associated with late diagnosis (p <or=.05). Late diagnosis remains a challenge despite good access to care. In our setting, effective risk assessment before symptoms arise offers greater potential for raising the mean CD4 cell count at diagnosis than does increased awareness of selected HIV-associated clinical prompts.

Relationship between nutritional status and the glomerular filtration rate: results from the MDRD study

BACKGROUND

The relationship between the protein-energy nutritional status and renal function was assessed in 1785 clinically stable patients with moderate to advanced chronic renal failure who were evaluated during the baseline phase of the Modification of Diet in Renal Disease Study. Their mean +/- SD glomerular filtration rate (GFR) was 39.8 +/- 21.1 mL/min/1.73 m2.

METHODS

The GFR was determined by 121I-iothalamate clearance and was correlated with dietary and nutritional parameters estimated from diet records, biochemistry measurements, and anthropometry.

RESULTS

The following parameters correlated directly with the GFR in both men and women: dietary protein intake estimated from the urea nitrogen appearance, dietary protein and energy intake estimated from dietary diaries, serum albumin, transferrin, percentage body fat, skinfold thickness, and urine creatinine excretion. Serum total cholesterol, actual and relative body weights, body mass index, and arm muscle area also correlated with the GFR in men. The relationships generally persisted after statistically controlling for reported efforts to restrict diets. Compared with patients with GFR > 37 mL/min/1.73 m2, the means of several nutritional parameters were significantly lower for GFR between 21 and 37 mL/min/1.73 m2, and lower still for GFRs under 21 mL/min/1.73 m2. In multivariable regression analyses, the association of GFR with several of the anthropometric and biochemical nutritional parameters was either attenuated or eliminated completely after controlling for protein and energy intakes, which were themselves strongly associated with many of the nutritional parameters. On the other hand, few patients showed evidence for actual protein-energy malnutrition.

CONCLUSIONS

These cross-sectional findings suggest that in patients with chronic renal disease, dietary protein and energy intakes and serum and anthropometric measures of protein-energy nutritional status progressively decline as the GFR decreases. The reduced protein and energy intakes, as GFR falls, may contribute to the decline in many of the nutritional measures.

Risk of repetition of a severe perineal laceration

OBJECTIVE

To compare the outcome of subsequent delivery in women with a history of a third- or fourth-degree laceration with outcomes in women without such a history.

METHODS

This retrospective study used a perinatal database and chart review from 1978 to 1995. Only women whose first delivery was at our institution at more than 36 weeks' gestation, vaginal singleton, vertex presentation, and birth weight greater than 2500 g, with a subsequent delivery were included. The women were grouped by presence or absence of a third- or fourth-degree (severe) perineal laceration in their first delivery. The subsequent delivery was analyzed for maternal age, weight, birth weight, gestational age, method of delivery, use of episiotomy, and occurrence of a severe laceration. Comparison of data was by Fisher exact and t tests.

RESULTS

Four thousand fifteen women met our starting criteria. In their first delivery, the average birth weight, use of instrumentation, and episiotomy rate were significantly higher in those women sustaining a severe laceration. When compared with women without a history of severe perineal laceration, women with such a history were at more than twice the risk for another in their subsequent delivery. The women at highest risk (21.4%) were those sustaining a laceration in their first delivery who underwent instrumental vaginal delivery with episiotomy in their subsequent delivery. When episiotomy or instrumental delivery was performed in the second vaginal birth, 52 (11.6%) of 449 women with a history of a severe perineal laceration sustained another, compared with 98 (6.5%) of 1509 without such a history (P < .001, odds ratio 1.9, 95% confidence interval 1.3, 2.7).

CONCLUSION

Women delivering their second baby, and in whom episiotomy or instrumentation is used, are at increased risk of severe perineal laceration compared with women delivery spontaneously.

Interactions between color and word processing in a flanker task

To examine interactions between color and word attributes, participants responded, either manually or vocally, to a central target (color patch or word) flanked by a Stroop stimulus. Color and word attributes of the flanker affected both vocal and manual responding to color patches. Color and word flankers also affected manual responding to word targets, but only word flanker affected vocal responding to word targets. These results are not consistent with models (e.g., translational models) of Stroop tasks, which posit that interactions between colors and words occur only when vocal responding is required.

Interactions between color and word processing in a flanker task

To examine interactions between color and word attributes, participants responded, either manually or vocally, to a central target (color patch or word) flanked by a Stroop stimulus. Color and word attributes of the flanker affected both vocal and manual responding to color patches. Color and word flankers also affected manual responding to word targets, but only word flanker affected vocal responding to word targets. These results are not consistent with models (e.g., translational models) of Stroop tasks, which posit that interactions between colors and words occur only when vocal responding is required.

Effect of dietary protein restriction on nutritional status in the Modification of Diet in Renal Disease Study

The safety of dietary protein and phosphorous restriction was evaluated in the Modification of Diet in Renal Disease (MDRD) Study. In Study A, 585 patients with a glomerular filtration rate (GFR) of 25 to 55 ml/min/1.73 m2 were randomly assigned to a usual-protein diet (1.3 g/kg/day) or a low-protein diet (0.58 g/kg/day). In Study B, 255 patients with a GFR of 13 to 24 ml/min/1.73 m2 were randomly assigned to the low-protein diet or a very-low-protein diet (0.28 g/kg/day), supplemented with a ketoacid-amino acid mixture (0.28 g/kg/day). The low-protein and very-low-protein diets were also low in phosphorus. Mean duration of follow-up was 2.2 years in both studies. Protein and energy intakes were lower in the low-protein and very-low-protein diet groups than in the usual-protein group. Two patients in Study B reached a "stop point" for malnutrition. There was no difference between randomized groups in the rates of death, first hospitalizations, or other "stop points" in either study. Mean values for various indices of nutritional status remained within the normal range during follow-up in each diet group. However, there were small but significant changes from baseline in some nutritional indices, and differences between the randomized groups in some of these changes. In the low-protein and very-low-protein diet groups, serum albumin rose, while serum transferrin, body wt, percent body fat, arm muscle area and urine creatinine excretion declined. Combining patients in both diet groups in each study, a lower achieved protein intake (from food and supplement) was not correlated with a higher rate of death, hospitalization or stop points, or with a progressive decline in any of the indices of nutritional status after controlling for baseline nutritional status and follow-up energy intake. These analyses suggest that the low-protein and very-low-protein diets used in the MDRD Study are safe for periods of two to three years. Nonetheless, both protein and energy intake declined and there were small but significant declines in various indices of nutritional status. These declines are of concern because of the adverse effect of protein calorie malnutrition in patients with end-stage renal disease. Physicians who prescribe low-protein diets must carefully monitor patients' protein and energy intake and nutritional status.

A placebo-controlled randomized trial of the terbutaline pump for prevention of preterm delivery

To determine the efficacy of the terbutaline pump for the prevention of preterm delivery, patients in preterm labor defined by progressive cervical change underwent intravenous magnesium sulfate tocolysis (with or without oral indomethacin, as necessary), and once labor was arrested, were randomized to one of three treatment arms: terbutaline by pump, saline by pump (blinded), or oral terbutaline. If recurrent preterm labor occurred despite maximization of therapy, the treatment arm was determined and therapy was changed; saline pump and oral terbutaline were switched to terbutaline pump, terbutaline pump was switched to oral terbutaline. Patients who continued to labor were readmitted for aggressive intravenous therapy. Women randomized to the terbutaline pump (n = 15), saline pump (n = 12), and oral terbutaline (n = 15) groups were similar in terms of gravidity, parity, days of tocolysis before study entry, gestational age at entry, and cervical dilatation at entry. The mean gestational age at delivery was the same in all three groups (35 weeks), as were neonatal outcomes. Terbutaline by pump, saline by pump, and oral terbutaline appear equivalent for the prevention of preterm delivery. The terbutaline pump should remain experimental.

Epidural recording of nerve conduction studies and surgical findings in radiculopathy

We developed a method of studying nerve conduction along proximal nerves and nerve roots by delivering supramaximal stimuli to the tibial and peroneal nerves within the popliteal space and recording compound nerve action potentials from an epidural needle electrode at the L4-L5 interspace. For the purpose of investigating lumbar radiculopathies, a battery of averaged potentials was developed that could be read side-to-side for symmetry of amplitude and latency. Decreased amplitude and/or increased latency in peroneal or tibial conduction studies was attributed to L5 or S1 root pathology respectively. We report on 22 patients who were studied with this method and subsequently went to surgery. To evaluate the ability of the procedure to predict surgical findings, we reviewed the last 155 patients that we studied using epidural recording to find those who had subsequently gone to surgery and were sufficiently documented to allow analysis. The review yielded 22 cases and 69 root levels whose condition had been reported at surgery and studied by our method. Agreement was above what might be expected by chance p < .0001 (7.462; sign). The agreement on nerve root condition between nerve conduction studies and surgical findings suggests that the procedure's usefulness for confirming and localizing pathology in nerve root entrapments is similar to that offered by nerve conduction studies for entrapment neuropathies elsewhere.

Class II furcations treated by guided tissue regeneration in humans: case reports

In the cases reported here, the response of Class II mandibular molar furcation defects to guided tissue regeneration (GTR) versus sham operation was evaluated. Base-line information, including probing pocket depth (PD) and clinical attachment level (CAL) measurements, was recorded after completion of the hygienic phase. Eleven experimental and six control furcations, randomly assigned, are included in this report. The furcations were surgically exposed, using a flap approach and the areas were debrided. On the experimental teeth, Gore-Tex periodontal material was adapted and sutured, using a suspensory suture. The flaps were then sutured tightly, assuring complete coverage to the material. For 1 month all patients were seen weekly and rinsed their mouths with an 0.12% chlorhexidine solution daily. After 4 to 6 weeks the Gore-Tex membranes were removed. Clinical measurements were repeated at 3 and 6 months following surgery. Changes from baseline in PD and CAL were calculated for each case. Results indicated that PD measurements were reduced by both procedures, but the reduction was better for GTR at 3 and 6 months. At six months the test sites showed 2.8 +/- 1.0 mm pocket reduction, while the control sites showed an average of 1.6 +/- 0.9 mm reduction in pocket depth. CAL recordings were improved by both treatments, but were better for GTR at 6 months, with an average gain in CAL of 1.8 mm for the GTR and 0.6 mm for the controls. These cases in which GTR was compared to sham-operated controls indicate that GTR can improve the response to therapy of Class II furcation defects.

Detection of excess disease near an exposure point: a case study

Many studies have evaluated the likelihood of adverse health effects associated with environmental contamination from point source exposures. Two statistical measures used in these studies are the ratio, R, of the observed to the expected number of cases occurring in the area containing the point and the average distance, D, between the cases and the point. This paper estimates the probability of detecting an association between disease and exposure when one actually exists (power) for R and D for several specific and plausible statistical models. Results are presented in the context of rare diseases such as congenital malformations. The practical implications of using these measures for the evaluation of risk of disease in environmental epidemiologic investigations are discussed.

An examination of three spatial disease clustering methodologies

Patterns of disease in space are often analysed to determine whether a relationship exists between a disease outcome and environmental exposures. This report examines the performance of three cluster analytical methods when applied to a single data set. These methods, designed to assess the purely spatial variation of events, have been examined to assess their ability to detect clustering in an area where disease rates have previously been shown to be significantly elevated. The ability of these methods to detect spatial clustering was also examined using simulation techniques. All three methods were found to be poor at detecting spatially localized disease rates which were approximately three time the expected rate, as measured by the relative risk.

Stereoselectivity of tocainide pharmacodynamics in vivo and in vitro

Racemic tocainide [R,S-T], which is used in the treatment of ventricular arrhythmias, consists of an R(-)-enantiomer [R-T] and an S(+)-enantiomer [S-T]. The present experiments examined these substances for pharmacodynamic differences. The ability of various doses of R-T, S-T, and R,S-T to both induce ataxia (A) and protect against chloroform-induced ventricular arrhythmias (P) in mice were compared at 20 min after subcutaneous treatment. For A effects, the ED50S (95% Fieller Limits) of R-T, S-T, and R,S-T were 125 (78-802), 125 (84-283), and 90 (61-149) mg/kg, respectively. For P effects, the ED50S were 40 (11-71), 116 (82-204), and 86 (55-187) mg/kg. The ratios of A/P, a measure of the margin of safety, were 3.1, 1.1, and 1.0. Effects upon intracardiac conduction in isolated rabbit hearts also exhibited, qualitatively, similar patterns of selectivity. At 1 X 10(-4) M intraatrial, His-Purkinje, intraventricular conduction times, and the QT interval were prolonged with the following order of potency: R-T greater than R,S-T greater than S-T; A-V nodal conduction was unchanged. R-T also evoked the greatest decrease in contractility. With respect to separation of antiarrhythmic action and the production of ataxia, R-T has a greater margin of safety than either S-T or R,S-T.

Transformations of maps to investigate clusters of disease

An approach is presented to display and analyze epidemiologic data using population density equalized maps (cartograms). The algorithm for generating these maps is discussed. A specific method for statistically analyzing plotted data is given, followed by an application of maps and analysis to 73 sets of age-, race-, sex-, and site-specific cancer incidence data. The data were obtained from the Surveillance, Epidemiology and End Results project for San Francisco City/County (1978-1981) and combined with 1980 U.S. Census data.

Intra-oral effects on acid-softened enamel of NaF lozenges administered in divided daily doses

The purpose of this investigation was to study the intra-oral effects of multiple daily applications of NaF lozenges upon acid-softened enamel. Bovine enamel slabs were softened with 0.1 mol/L lactate buffer at pH 4.0 for 14 hrs and subsequently mounted in a mandibular removable Hawley appliance. Control slabs were worn for seven days by eight adult male subjects who brushed their natural dentition daily with a fluoride-free dentifrice. Test slabs were exposed to one 0.55-mg NaF lozenge (0.25 mg F) 4x/day for seven days and the natural dentition brushed with a fluoride-free dentifrice. The efficacy of 0.25-mg F lozenges used 4x/day over that of a 1-mg F lozenge administered 1x/day was established by a pilot study with two subjects. Microhardness testing was performed after intra-oral exposure (IOE) and following immersion in 0.01 mol/L lactate buffer containing Ca and PO4 for 24 hrs at a pH of 4.0. Fluoride uptake was measured on separate control and test slabs after KOH wash and after acid-resistance-testing (ART). Recovery of microhardness following IOE was 40.9% for controls and 53.9% for treated slabs, while control slabs retained 1.3% resistance to ART, compared with 25.6% for test slabs. The F content of the control slabs was significantly less than that of lozenge-treated and lozenge-treated-ART slabs throughout the depth of the lesion. The F content of the lozenge-treated-ART slabs was significantly less than that of the lozenge-treated slabs only at the 0-5-microns depth.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of renal function on enalapril kinetics

Enalapril maleate (MK-421), a nonmercapto-containing angiotensin converting enzyme (ACE) inhibitor, is converted in vivo to enalaprilat (MK-422), the active diacid. We evaluated serum profiles and urinary excretion of oral enalapril maleate in patients with renal disease (group I, creatinine clearance less than 3 ml/min, patients undergoing dialysis, n = 10; group II, creatinine clearance 10 to 79 ml/min, n = 9) compared with healthy subjects (group III, creatinine clearance greater than 80 ml/min, n = 10). Group I received a 10 mg dose during a day while not receiving dialysis and a 10 mg dose 1 hour before dialysis 2 weeks later. Groups II and III received a single 10 mg dose. Blood samples and urine were collected for 48 hours. Impaired renal function resulted in elevated serum and plasma concentrations of enalapril maleate and decreased excretion rates and urinary recovery of enalapril maleate and enalaprilat. The data suggest an apparent increase in the extent of metabolism of enalapril maleate to enalaprilat or an increase in nonrenal elimination of unchanged enalapril maleate in renal disease compared with normal health. Enalaprilat was dialyzable.

Control of ACTH and vasopressin in neurohypophysectomized conscious dogs

Adrenocorticotropin (ACTH), cortisol, and vasopressin responses to clamped decreases in blood pressure (MAP) and to ovine corticotropin-releasing factor (CRF) infusion (20 ng X kg-1 X min-1) in intact and neurohypophysectomized (NHX) conscious dogs were examined. Mean arterial blood pressure was decreased 28 mmHg by a controlled infusion of sodium nitroprusside. Hypotension induced large increases in ACTH (peak 164 +/- 25 pg/ml), cortisol (peak 12.5 +/- 2.5 micrograms/dl), and vasopressin (peak 221 +/- 64 pg/ml) in intact (n = 7) dogs. NHX (n = 7) significantly attenuated these responses to hypotension. CRF infusion induced increases in ACTH similar in intact (n = 4) and NHX (n = 4) dogs. However, cortisol responses were significantly attenuated by NHX. Interestingly, CRF infusion induced small but significant increases in vasopressin from 3.0 +/- 1.1 to 8.1 +/- 2.0 pg/ml. We conclude that NHX attenuates ACTH and vasopressin responses to hypotension and cortisol responses to CRF-induced increases in ACTH. CRF seems to stimulate vasopressin release.

Ecologic regression analysis and the study of the influence of air quality on mortality

This presentation focuses entirely on the use and evaluation of regression analysis applied to ecologic data as a method to study the effects of ambient air pollution on mortality rates. Using extensive national data on mortality, air quality and socio-economic status regression analyses are used to study the influence of air quality on mortality. The analytic methods and data are selected in such a way that direct comparisons can be made with other ecologic regression studies of mortality and air quality. Analyses are performed by use of two types of geographic areas, age-specific mortality of both males and females and three pollutants (total suspended particulates, sulfur dioxide and nitrogen dioxide). The overall results indicate no persuasive evidence exists of a link between air quality and general mortality levels. Additionally, a lack of consistency between the present results and previous published work is noted. Overall, it is concluded that linear regression analysis applied to nationally collected ecologic data cannot be used to usefully infer a causal relationship between air quality and mortality which is in direct contradiction to other major published studies.

Influence of vasopressin and angiotensin on baroreflexes in the dog

Cardiovascular responses to step-changes of carotid sinus pressure were evaluated at normal and elevated levels of plasma arginine vasopressin in anesthetized neurohypophysectomized dogs (n = 12). Arginine vasopressin influenced autonomic function in two ways: first, maximum carotid reflex gain increased; second, cardiac output was decreased. The enhancement of reflex strength was observed only in response to decreases of intrasinus pressure below the equilibrium point (pressures of between 60 and 105 mm Hg). Aortic pressure rose twice as high for a given decrease of intrasinus pressure, elevations of total peripheral resistance responses were triple those observed at normal plasma arginine vasopressin. In this way, arginine vasopressin more than doubled the ability of the carotid reflexes to return a drop in arterial pressure to normal. Arginine vasopressin enhancement of reflex gain was not observed with elevations of intrasinus pressures above the equilibrium point. Elevation of aortic pressure expected from the vasoconstrictor actions of infused arginine vasopressin were buffered by associated reductions in cardiac output. Vagally mediated bradycardia was consistently observed with elevated arginine vasopressin, but the reflex response of heart rate to step-changes of intrasinus pressure was unchanged. Time control studies in five neurohypophysectomized dogs indicated no significant change in carotid reflex response over the 3- to 4-hour protocol. Comparison of reflex responses in anephric dogs (n = 8) at low and elevated levels of angiotensin II indicated that this vasoactive peptide did not significantly alter reflex responsiveness. We conclude that arginine vasopressin enhances the ability of the carotid reflexes to normalize decreases of arterial pressure, but buffers a rise in pressure from its own vasoactive properties by initiating a fall of cardiac output.

Inability of seven-pinhole myocardial tomography to obtain accurate 201Tl kinetic data

Seven-pinhole myocardial tomography has been reported to enhance the accuracy of thallium-201 (201Tl) studies in detecting patients with coronary artery disease. To determine if this approach can accurately assess regional 201Tl kinetics, 12 dogs with temporary occlusion (mean 15 min) of either the left anterior descending (LAD) (n = 6) or left circumflex (LCX) (n = 6) coronary artery were studied. Thallium-201 was injected and serial 7-pinhole images were acquired during occlusion and following reflow (mean duration 175 min). Time-activity analysis was obtained from normal and ischemic regions of interest in the central pinhole image and the reconstructed tomographic images (TOMO-ROI). Time-activity data from corresponding normal and ischemic regions were also obtained using a circumferential graph program (TOMO-MAX). In addition, regional myocardial 201Tl activity was recorded continuously with a cadmium telluride radiation probe sutured directly to the posterior myocardial wall. Defects in 201Tl distribution with subsequent partial or complete redistribution were present in 11 of 12 central pinhole images and tomographic studies. In the normal and ischemic anterior myocardial segments the percentage change in 201Tl activity in the central pinhole image from occlusion to the end of reflow correlated well with the percentage change in activity for both TOMO-ROI (r = 0.93) and TOMO-MAX (r = 0.85). In the normal posterior segments the percentage change in 201Tl activity in the central pinhole image correlated well with TOMO-ROI (r = 0.98) and TOMO-MAX (r = 0.87).(ABSTRACT TRUNCATED AT 250 WORDS)

An alternative to ecologic regression analysis of mortality rates

A number of recent papers have used geographically defined data and linear models to study the relationship between a series of epidemiologic factors and the frequency of disease. This "ecologic regression" approach involves serious problems of interpretation. An alternate approach is discussed that does not depend on statistical models, produces easily interpreted results and yields statistical summaries that approximately parallel regression analysis. This alternative procedure is illustrated by using acute lymphocytic leukemia mortality data on a county level from among white females less than five years of age between 1969-1977.

Requirement for OKT8+ suppressor cell proliferation for suppression by human newborn T cells

The percentage of cells bearing the suppressor phenotype OKT8+increases in PWM-stimulated cultures of human newborn lymphocytes. Prevention of this increase either by adding 50 microM deoxyguanosine to the cultures of by pretreating the newborn cells with OKT8 and complement reduced the suppressor activity of newborn T cells. These results suggest that newborn T cells are not intrinsically suppressive, but that they become so in vitro after stimulation by PWM.