The 3 + 3 design in dose-finding studies with small sample sizes: Pitfalls and possible remedies.

In the last few years, numerous novel designs have been proposed to improve the efficiency and accuracy of phase I trials to identify the maximum-tolerated dose (MTD) or the optimal biological dose (OBD) for noncytotoxic agents. However, the conventional 3+3 approach, known for its and poor performance, continues to be an attractive choice for many trials despite these alternative suggestions. The article seeks to underscore the importance of moving beyond the 3+3 design by highlighting a different key element in trial design: the estimation of sample size and its crucial role in predicting toxicity and determining the MTD. We use simulation studies to compare the performance of the most used phase I approaches: 3+3, Continual Reassessment Method (CRM), Keyboard and Bayesian Optimal Interval (BOIN) designs regarding three key operating characteristics: the percentage of correct selection of the true MTD, the average number of patients allocated per dose level, and the average total sample size. The simulation results consistently show that the 3+3 algorithm underperforms in comparison to model-based and model-assisted designs across all scenarios and metrics. The 3+3 method yields significantly lower (up to three times) probabilities in identifying the correct MTD, often selecting doses one or even two levels below the actual MTD. The 3+3 design allocates significantly fewer patients at the true MTD, assigns higher numbers to lower dose levels, and rarely explores doses above the target dose-limiting toxicity (DLT) rate. The overall performance of the 3+3 method is suboptimal, with a high level of unexplained uncertainty and significant implications for accurately determining the MTD. While the primary focus of the article is to demonstrate the limitations of the 3+3 algorithm, the question remains about the preferred alternative approach. The intention is not to definitively recommend one model-based or model-assisted method over others, as their performance can vary based on parameters and model specifications. However, the presented results indicate that the CRM, Keyboard, and BOIN designs consistently outperform the 3+3 and offer improved efficiency and precision in determining the MTD, which is crucial in early-phase clinical trials.

Physical Performance in Black and Hispanic Outpatients With Heart Failure: The SCAN-MP Study.

Background: Deficits of physical function are associated with poor quality of life and adverse health outcomes, but data informing the association of these assessments among Black and Hispanic outpatients with heart failure (HF) are limited. Methods: The multicentre, prospective Screening for Cardiac Amyloidosis With Nuclear Imaging for Minority Populations (SCAN-MP) study identified Black and Hispanic subjects with stable HF, collected baseline characteristics, and took measures using the short physical performance battery. Subjects completed a Kansas City Cardiomyopathy Questionnaire (KCCQ), and the clinical outcomes of HF hospitalization and death were ascertained by telephone and review of the electronic health record. Results: Of 320 participants, 227 (70.9%) had physical deficits, defined by a battery score of ≤ 9. Patients with severe physical deficits reported overall lower KCCQ scores compared to those with no deficits (KCCQ score of 57.0 vs 72.4, P < 0.001). Physical limitation was significantly associated with risk of HF hospitalization, after adjustments for age, sex, and New York Heart Association class (severe physical deficit hazard ratio, 3.61; 95% confidence interval [CI], 1.19-10.93; P = 0.024; mild physical deficit hazard ratio, 2.59; 95% CI, 0.86-7.75; P = 0.090). Conclusions: Reduced physical performance is highly prevalent among Black and Hispanic outpatients with HF, and it is associated with overall KCCQ score, as well as an increased risk for HF hospitalization.

Contexte: La limitation physique est associée à une détérioration de la qualité de vie et à une aggravation de l'état de santé, mais il y a peu de données sur la corrélation entre ces paramètres chez les patients externes noirs et hispaniques atteints d'insuffisance cardiaque. Méthodologie: Dans l'étude multicentrique et prospective de dépistage de l'amylose cardiaque chez les populations minoritaires (SCAN-MP), on a ciblé des sujets noirs et hispaniques atteints d'insuffisance cardiaque stable, recueilli les caractéristiques initiales et mesuré les capacités au moyen du court test d'évaluation de la performance physique (short physical performance battery [SPPB]). Les sujets ont répondu au questionnaire de cardiomyopathie de Kansas City (KCCQ), et les critères cliniques des hospitalisations et des décès liés à l'insuffisance cardiaque ont été évalués par téléphone et par examen des dossiers de santé électroniques. Résultats: Des 320 participants, 227 (70,9 %) avaient des déficits physiques, définis par un score au SPPB de 9 ou moins. Les patients ayant des déficits physiques graves ont obtenu des scores globaux au KCCQ inférieurs aux patients sans déficit (score KCCQ de 57,0 contre 72,4; p < 0,001). La limitation physique est fortement associée au risque d'hospitalisation liée à l'insuffisance cardiaque, après ajustement pour tenir compte de l'âge, du sexe et de la classe d'insuffisance cardiaque de la New York Heart Association (rapport des risques instantanés [RRI] du déficit physique grave : 3,61; intervalle de confiance [IC] à 95 % de 1,19 à 10,93; p = 0,024; RRI du déficit physique léger : 2,59; IC à 95 % de 0,86 à 7,75; p = 0,090). Conclusions: La diminution de la performance physique est très fréquente chez les patients externes noirs et hispaniques atteints d'insuffisance cardiaque, et elle est corrélée au score global au KCCQ ainsi qu'à une augmentation du risque d'hospitalisation liée à l'insuffisance cardiaque.

Is more better? An analysis of toxicity and response outcomes from dose-finding clinical trials in cancer.

BACKGROUND: The overwhelming majority of dose-escalation clinical trials use methods that seek a maximum tolerable dose, including rule-based methods like the 3+3, and model-based methods like CRM and EWOC. These methods assume that the incidences of efficacy and toxicity always increase as dose is increased. This assumption is widely accepted with cytotoxic therapies. In recent decades, however, the search for novel cancer treatments has broadened, increasingly focusing on inhibitors and antibodies. The rationale that higher doses are always associated with superior efficacy is less clear for these types of therapies. METHODS: We extracted dose-level efficacy and toxicity outcomes from 115 manuscripts reporting dose-finding clinical trials in cancer between 2008 and 2014. We analysed the outcomes from each manuscript using flexible non-linear regression models to investigate the evidence supporting the monotonic efficacy and toxicity assumptions. RESULTS: We found that the monotonic toxicity assumption was well-supported across most treatment classes and disease areas. In contrast, we found very little evidence supporting the monotonic efficacy assumption. CONCLUSIONS: Our conclusion is that dose-escalation trials routinely use methods whose assumptions are violated by the outcomes observed. As a consequence, dose-finding trials risk recommending unjustifiably high doses that may be harmful to patients. We recommend that trialists consider experimental designs that allow toxicity and efficacy outcomes to jointly determine the doses given to patients and recommended for further study.

An adaptive dose-finding design based on both safety and immunologic responses in cancer clinical trials.

Dose-finding in cancer clinical trials has been dominated by algorithmic designs on the principle that the highest tolerable dose is also the most effective dose. This assumption no longer applies to the biologic treatments that are characterized by different toxicity and/or efficacy profiles to the extent that the best therapeutic dose might be well below any dose that produces serious toxicity. As such, we propose a two-stage design with focus on immunotherapy trials, incorporating both safety and efficacy information. The 1st stage establishes the safety profile of each dose, with escalation decisions based on likelihood principles. Continuous immunologic outcomes are used to evaluate the relative efficacy of the doses. The 2nd stage employs an adaptive randomization to assign patients to doses showing higher efficacy. Safety is being continuously monitored throughout stage 2, where some doses may be 'closed' due to unacceptable toxicity. The proposed design is compared to the modified toxicity probability interval (mTPI) design using percent dose allocation and estimation of outcomes under different scenarios. We show that by using an efficacy-driven adaptive randomization with safety constraints, the allocation distribution is skewed towards more efficacious doses, and thus limit the number of patients exposed to toxic or non-therapeutic doses.

Design considerations for early-phase clinical trials of immune-oncology agents.

BACKGROUND: With numerous and fast approvals of different agents including immune checkpoint inhibitors, monoclonal antibodies, or chimeric antigen receptor (CAR) T-cell therapy, immunotherapy is now an established form of cancer treatment. These agents have demonstrated impressive clinical activity across many tumor types, but also revealed different toxicity profiles and mechanisms of action. The classic assumptions imposed by cytotoxic agents may no longer be applicable, requiring new strategies for dose selection and trial design. DESCRIPTION: This main goal of this article is to summarize and highlight main challenges of early-phase study design of immunotherapies from a statistical perspective. We compared the underlying toxicity and efficacy assumptions of cytotoxic versus immune-oncology agents, proposed novel endpoints to be included in the dose-selection process, and reviewed design considerations to be considered for early-phase trials. When available, references to software and/or web-based applications were also provided to ease the implementation. Throughout the paper, concrete examples from completed (pembrolizumab, nivolumab) or ongoing trials were used to motivate the main ideas including recommendation of alternative designs. CONCLUSION: Further advances in the effectiveness of cancer immunotherapies will require new approaches that include redefining the optimal dose to be carried forward in later phases, incorporating additional endpoints in the dose selection process (PK, PD, immune-based biomarkers), developing personalized biomarker profiles, or testing drug combination therapies to improve efficacy and reduce toxicity.

Recurrence of Optimally Treated Malignant Peritoneal Mesothelioma with Cytoreduction and Heated Intraperitoneal Chemotherapy.

BACKGROUND: The prognosis for patients with diffuse malignant peritoneal mesothelioma has dramatically improved with cytoreductive surgery and intraperitoneal chemotherapy. Little is known about disease recurrence after treatment. We analyzed the time to and predictors of recurrence in a large cohort of optimally treated patients. METHODS: We examined 113 patients completing a two-stage cytoreduction and intraperitoneal chemotherapy protocol. All patients achieved optimal surgical resection with completeness of cytoreduction (CC) score ≤ 1 and were divided into two groups based on absence (Group A) or presence (Group B) of gross disease at the outset of the second operation. Predictors of disease recurrence and recurrence-free survival (RFS) were determined using Cox proportional hazard regression modeling, and estimates were obtained by using the Kaplan-Meier method. RESULTS: Forty-six percent of patients had no gross evidence of disease at the second operation; the remaining 54% were cytoreduced to CC ≤ 1 (Group B). Forty-two percent of patients developed disease recurrence with a median recurrence-free survival of 38.5 months for the cohort; 79% of these received a form of iterative treatment. There was no statistically significant difference in recurrence-free survival between Group A (median RFS: 44.6 months) and B (median RFS: 35.5 months) (log-rank test, p = 0.06). Additionally, the only variable significantly associated with RFS was male gender (hazard ratio [HR] 1.98, 95% confidence interval [CI] 1.16-3.38). CONCLUSIONS: Absence of gross disease at the second operation was not statistically protective against recurrence compared with presence of quantifiable residual disease (Group B) that was effectively cytoreduced. Long-term disease surveillance is recommended, because recurrence continues years after treatment. Where a question of recurrence arises on surveillance, males may benefit from a higher degree of suspicion.

Dose-finding designs for trials of molecularly targeted agents and immunotherapies.

Recently, there has been a surge of early phase trials of molecularly targeted agents (MTAs) and immunotherapies. These new therapies have different toxicity profiles compared to cytotoxic therapies. MTAs can benefit from new trial designs that allow inclusion of low-grade toxicities, late-onset toxicities, addition of an efficacy endpoint, and flexibility in the specification of a target toxicity probability. To study the degree of adoption of these methods, we conducted a Web of Science search of articles published between 2008 and 2014 that describe phase 1 oncology trials. Trials were categorized based on the dose-finding design used and the type of drug studied. Out of 1,712 dose-finding trials that met our criteria, 1,591 (92.9%) utilized a rule-based design, and 92 (5.4%; range 2.3% in 2009 to 9.7% in 2014) utilized a model-based or novel design. Over half of the trials tested an MTA or immunotherapy. Among the MTA and immunotherapy trials, 5.8% used model-based methods, compared to 3.9% and 8.3% of the chemotherapy or radiotherapy trials, respectively. While the percentage of trials using novel dose-finding designs has tripled since 2007, the adoption of these designs continues to remain low.

Immediate implant placement and provisionalization in the aesthetic zone using a flapless or a flap-involving approach: a randomized controlled trial.

AIM: We conducted a randomized controlled trial to compare the effect of flapless (FLS) or flap-involving (F) immediate placement and provisionalization of single-tooth implants in the aesthetic zone. MATERIALS AND METHODS: Thirty-nine patients were randomized following extraction of a non-restorable tooth to a FLS or F group. All implants were immediately placed and provisionalized. We monitored prospectively changes in the peri-implant mucosal margin, the interproximal bone and buccal horizontal ridge at 3, 6 and 12 months. RESULTS: At 3 months post-surgery, the mean ± SD [median (interquartile range)] mesiobuccal peri-implant gingival margin recession from the pre-surgical soft tissue position amounted to 0.11 ± 0.32 mm [0 (0, 0.5)] in the FLS treatment arm versus 0.43 ± 37 mm [0.5 (0, 0.5)] in the F treatment arm (p = 0.02); corresponding values at the distobuccal surface were 0.11 ± 32 mm [0 (0, 0)] in the FLS arm versus 0.48 ± 0.44 mm [0.5 (0, 1)] in the F arm (p = 0.01). No other significant differences in soft or hard tissue remodelling between the treatment arms were observed at 3, 6 or 12 months. CONCLUSIONS: Flapless and a flap-involving immediate implant placement and provisionalization in the aesthetic zone resulted in comparable remodelling of the peri-implant mucosa, interproximal bone and buccal ridge at 6 and 12 months.

Risk of anastomotic leak after laparoscopic versus open colectomy.

BACKGROUND: Anastomotic leak following colorectal surgery is associated with significant morbidity and mortality. With the widespread adoption of laparoscopy, data from initial clinical trials evaluating the efficacy of laparoscopic when compared to open surgery may not currently be generalizable. We assess the risk of anastomotic leak after laparoscopic versus open colorectal resection using a nationwide database with standardized definitions. METHODS: The 2012-2013 ACS-NSQIP targeted colectomy data were queried for all elective colorectal resections. Characteristics were compared for those patients undergoing laparoscopic versus open operations. Univariable and multivariable analyses, followed by a propensity score-matched analysis, were performed to assess the impact of laparoscopy on the development of an anastomotic leak. RESULTS: Of 23,568 patients, 3.4 % developed an anastomotic leak. Laparoscopic surgery was associated with a leak rate of 2.8 % (n = 425) and open surgery, 4.5 % (n = 378, p < 0.0001). Patients who developed a leak were more likely to die within 30 days of surgery (5.7 vs. 0.6 %, p < 0.0001). Patients who underwent laparoscopic surgery compared to open were younger (61 vs. 63 years, p = 0, p = 0.045) and with fewer comorbidities. On univariable analysis laparoscopic surgery was associated with reduced odds of developing an anastomotic leak (OR 0.60, p < 0.0001), and this remained after adjusting for all significant preoperative and disease-related confounders (OR 0.69, 95 % CI 0.58-0.82). A propensity score-matched analysis confirmed benefit of laparoscopic surgery over open surgery for anastomotic leak. CONCLUSION: Laparoscopic colectomy is safe and associated with reduced odds of developing an anastomotic leak following colectomy when controlling for patient-, disease- and procedure-related factors.

The safety, efficacy, and durability of lung-volume reduction surgery: A 10-year experience.

OBJECTIVES: The National Emphysema Treatment Trial (NETT) validated the efficacy of lung-volume reduction surgery (LVRS) in selected patients with emphysema; however, concerns about the safety and durability of the operation have limited its clinical application. We evaluated our experience with LVRS, for the time period since approval was given by the Centers for Medicare and Medicaid Services, with respect to surgical morbidity and mortality, early and late functional outcomes, and long-term survival. METHODS: Retrospective analysis was performed on 91 patients for whom consent was obtained for bilateral LVRS at our institution between January 2004 and June 2014. Primary outcomes analyzed were 6-month surgical mortality and overall survival at 1, 2, and 5 years. Secondary outcomes (forced expiratory volume in 1 second [FEV1], residual volume, carbon monoxide diffusing capacity, a 6-minute walk test, exercise capacity, and a shortness-of-breath questionnaire) were analyzed for mean change from baseline at 1, 2, and 5 years after LVRS. RESULTS: The 6-month surgical mortality rate was 0%. At the 1- and 5-year follow-up, 69% and 36% of the patients had an improvement in FEV1. The 1-, 2-, and 5-year FEV1 change in % predicted of the FEV1, compared with baseline after LVRS, respectively, was 11.1% (95% CI: 8.6%, 13.6%); 8.7% (95% CI: 6.1%, 11.4%); and 11.1% (95% CI: 7.1%, 15.0%); and the maximal workload (in watts [W]) had an average increase of: 10.7 W (95% CI: 6.9, 14.6); 7.6 W (95% CI: 2.8, 12.4); and 10.24 W (95% CI: 4.4, 16.1). Overall survival (95% CI) for the group was: 0.99 (95% CI: 0.96, 1.00) at 1 year; 0.97 (95% CI: 0.93, 1.00) at 2 years; and 0.78 (95% CI: 0.67, 0.89) at 5 years. CONCLUSIONS: Given proper patient selection, LVRS is a safe operation. Early functional measurements are consistent with significant clinical benefit. Long-term results demonstrate that improvements can be durable. Surgical LVRS continues to represent the standard for lung-volume reduction therapy.

Sample size considerations for clinical research studies in nuclear cardiology.

Sample size calculation is an important element of research design that investigators need to consider in the planning stage of the study. Funding agencies and research review panels request a power analysis, for example, to determine the minimum number of subjects needed for an experiment to be informative. Calculating the right sample size is crucial to gaining accurate information and ensures that research resources are used efficiently and ethically. The simple question "How many subjects do I need?" does not always have a simple answer. Before calculating the sample size requirements, a researcher must address several aspects, such as purpose of the research (descriptive or comparative), type of samples (one or more groups), and data being collected (continuous or categorical). In this article, we describe some of the most frequent methods for calculating the sample size with examples from nuclear cardiology research, including for t tests, analysis of variance (ANOVA), non-parametric tests, correlation, Chi-squared tests, and survival analysis. For the ease of implementation, several examples are also illustrated via user-friendly free statistical software.

Combined preoperative mechanical bowel preparation with oral antibiotics significantly reduces surgical site infection, anastomotic leak, and ileus after colorectal surgery.

OBJECTIVES: To clarify whether bowel preparation use or its individual components [mechanical bowel preparation (MBP)/oral antibiotics] impact specific outcomes after colorectal surgery. METHODS: National Surgical Quality Improvement Program-targeted colectomy data initiated in 2012 capture information on the use/type of bowel preparation and colorectal-specific complications. For patients undergoing elective colorectal resection, the impact of preoperative MBP and antibiotics (MBP+/ABX+), MBP alone (MBP+/ABX-), and no bowel preparation (no-prep) on outcomes, particularly anastomotic leak, surgical site infection (SSI), and ileus, were evaluated using unadjusted/adjusted logistic regression analysis. RESULTS: Of 8442 patients, 2296 (27.2%) had no-prep, 3822 (45.3%) MBP+/ABX-, and 2324 (27.5%) MBP+/ABX+. Baseline characteristics were similar; however, there were marginally more patients with prior sepsis, ascites, steroid use, bleeding disorders, and disseminated cancer in no-prep. MBP with or without antibiotics was associated with reduced ileus [MBP+/ABX+: odds ratio (OR) = 0.57, 95% confidence interval (CI): 0.48-0.68; MBP+/ABX-: OR = 0.78, 95% CI: 0.68-0.91] and SSI [MBP+/ABX+: OR = 0.39, 95% CI: 0.32-0.48; MBP+/ABX-: OR = 0.80, 95% CI: 0.69-0.93] versus no-prep. MBP+/ABX+ was also associated with lower anastomotic leak rate than no-prep [OR = 0.45 (95% CI: 0.32-0.64)]. On multivariable analysis, MBP with antibiotics, but not without, was independently associated with reduced anastomotic leak (OR = 0.57, 95% CI: 0.35-0.94), SSI (OR = 0.40, 95% CI: 0.31-0.53), and postoperative ileus (OR = 0.71, 95% CI: 0.56-0.90). CONCLUSIONS: These data clarify the near 50-year debate whether bowel preparation improves outcomes after colorectal resection. MBP with oral antibiotics reduces by nearly half, SSI, anastomotic leak, and ileus, the most common and troublesome complications after colorectal surgery.

Survival of melanoma patients with brain metastases treated with ipilimumab and stereotactic radiosurgery.

UNLABELLED: Historically, melanoma with brain metastases has a poor prognosis. In this retrospective medical record review, we report the outcome of patients with stage IV melanoma with brain metastases treated with ipilimumab and brain stereotactic radiosurgery (SRS). All patients with metastatic melanoma treated with ipilimumab from June 2010 to September 2012 were identified and stratified by presence (A) or absence (B) of brain metastases at the time of ipilimumab administration. All patients with brain metastases received SRS. Overall survival (OS) was defined as time from the date of stage IV diagnosis and the time of ipilimumab administration to death or last follow-up. Survival curves were estimated using the Kaplan-Meier method, and Cox proportional hazards model was employed to compute the hazard ratios (HR). RESULTS: Five out of 10 patients in Cohort A and 10 out of 21 patients in Cohort B died as of last follow-up. In Cohort A, median number of lesions treated with SRS was 3. Median survivals from date of stage IV for Cohorts A and B were 29.3 and 33.1 months, respectively (HR = 0.93, P = 0.896). Median survival from cycle 1 ipilimumab was 16.5 and 24.5 months for Cohort A and B, respectively (HR = 1.05, P = 0.931). The 3-year survival rates from the date of cycle one of ipilimumab administration for Cohort A and B were 50% (95% CI: 27-93%) and 39% (95% CI: 19-81%), respectively. Eight of 10 patients in Cohort A maintained a good PS. Survival of patients with melanoma brain metastases treated with ipilimumab combined with SRS may be comparable to patients without brain metastases.

A likelihood-based approach for computing the operating characteristics of the 3+3 phase I clinical trial design with extensions to other A+B designs.

BACKGROUND: In phase I clinical trials, the "3+3" algorithmic design has been unparalleled in its popularity. The statistical properties of the "3+3" design have been studied in the literature either in comparison with other methods or by deriving exact formulae of statistical quantities. However, there is still much to be known about its capabilities of describing and accounting for uncertainties in the observed data. PURPOSE: The objective of this study is to provide a probabilistic support for analyzing the heuristic performance of the "3+3" design. The operating characteristics of the algorithm are computed under different hypotheses, levels of evidence, and true (or best guessed) toxicity rates. The dose-finding rules are further compared with those generated by the modified toxicity probability interval design and generalized for implementation in all "A+B" designs. METHODS: Our likelihood method is based on the evidential paradigm. Two hypotheses are chosen to correspond to two hypothesized dose-limiting toxicity rates, for example, [Formula: see text]-unsafe versus [Formula: see text]-acceptable. Given observed toxicities per dose, the likelihood-ratio is calculated and compared to a certain k threshold (level of evidence). Under various true toxicities, the probabilities of weak evidence, favoring [Formula: see text] and [Formula: see text], were computed under four sets of hypotheses and several k thresholds. RESULTS: For scenarios where the midpoint of the two hypothesized dose-limiting toxicity rates is around 0.30, and for a threshold of k = 2, the "3+3" design has a reduced probability (≈0.50) of identifying unsafe doses, but high chances of identifying acceptable doses. For more extreme scenarios targeting a relatively high or relatively low dose-limiting toxicity rate, the "3+3" design has no probabilistic support, and therefore, it should not be used. In our comparisons, the likelihood method is in agreement with the modified toxicity probability interval design for the majority of the hypothesized scenarios. Even so, based on the evidential paradigm, a "3+3" design is often incapable of providing sufficient levels of evidence of acceptability for doses under reasonable scenarios. LIMITATIONS: Given the small sample size per dose, the levels of evidence are limited in their ability to provide strong evidence favoring either of the hypotheses. CONCLUSION: In many situations, the "3+3" design does not treat enough patients per dose to have confidence in correct dose selection and the safety of the selected/unselected doses. This likelihood method allows consistent inferences to be made at each dose level, and evidence to be quantified regardless of cohort size. The approach can be used in phase I studies for identifying acceptably safe doses, but also for defining stopping rules in other types of dose-finding designs.

Improving the predictive accuracy of identifying exudative effusions.

BACKGROUND: Application of Light's criteria results in misclassification of some transudative effusions as exudative, particularly because of congestive heart failure (CHF). We sought to determine if the serum to pleural fluid albumin (SF-A) and serum to pleural fluid protein (SF-P) gradients increased the predictive accuracy to correctly identify exudative effusions. METHODS: We retrospectively analyzed 1,153 consecutive patients who underwent a diagnostic thoracentesis at the Medical University South Carolina. Univariable logistic regression analyses were used to determine the statistical significance of pleural fluid tests that correctly identified exudative effusions. Tests with significant diagnostic accuracy were combined in multivariable logistic regression models, with calculation of areas under the curve (AUCs) to determine their predictive accuracy. The predictive capability of the best model was compared with Light's criteria and other test combinations. RESULTS: Pleural fluid lactate dehydrogenase (LDH), SF-A gradient, and SF-P gradient had a significant effect on the probability of identifying exudative pleural effusions. When combined together in a multivariable logistic regression, LDH (OR, 14.09 [95% CI, 2.25-85.50]), SF-A gradient (OR, 7.16 [95% CI, 1.24-41.43]), and SF-P gradient (OR, 6.83 [95% CI, 1.56-27.88]) had an AUC of 0.92 (95% CI, 0.85-0.98). CONCLUSIONS: Application of Light's criteria, not uncommonly, misclassifies CHF transudative effusions as exudates. In cases where no cause for an exudative effusion can be identified or CHF is suspected, the sequential application of the fluid LDH, followed by the SF-P and then the SF-A gradients, may assist in reclassifying pleural effusions as transudates.

G-CSF/anti-G-CSF antibody complexes drive the potent recovery and expansion of CD11b+Gr-1+ myeloid cells without compromising CD8+ T cell immune responses.

BACKGROUND: Administration of recombinant G-CSF following cytoreductive therapy enhances the recovery of myeloid cells, minimizing the risk of opportunistic infection. Free G-CSF, however, is expensive, exhibits a short half-life, and has poor biological activity in vivo. METHODS: We evaluated whether the biological activity of G-CSF could be improved by pre-association with anti-G-CSF mAb prior to injection into mice. RESULTS: We find that the efficacy of G-CSF therapy can be enhanced more than 100-fold by pre-association of G-CSF with an anti-G-CSF monoclonal antibody (mAb). Compared with G-CSF alone, administration of G-CSF/anti-G-CSF mAb complexes induced the potent expansion of CD11b+Gr-1+ myeloid cells in mice with or without concomitant cytoreductive treatment including radiation or chemotherapy. Despite driving the dramatic expansion of myeloid cells, in vivo antigen-specific CD8+ T cell immune responses were not compromised. Furthermore, injection of G-CSF/anti-G-CSF mAb complexes heightened protective immunity to bacterial infection. As a measure of clinical value, we also found that antibody complexes improved G-CSF biological activity much more significantly than pegylation. CONCLUSIONS: Our findings provide the first evidence that antibody cytokine complexes can effectively expand myeloid cells, and furthermore, that G-CSF/anti-G-CSF mAb complexes may provide an improved method for the administration of recombinant G-CSF.

Altered circulating leukocytes and their chemokines in a clinical trial of therapeutic hypothermia for neonatal hypoxic ischemic encephalopathy*.

OBJECTIVES: To determine systemic hypothermia's effect on circulating immune cells and their corresponding chemokines after hypoxic ischemic encephalopathy in neonates. DESIGN: In our randomized, controlled, multicenter trial of systemic hypothermia in neonatal hypoxic ischemic encephalopathy, we measured total and leukocyte subset and serum chemokine levels over time in both hypothermia and normothermia groups, as primary outcomes for safety. SETTING: Neonatal ICUs participating in a Neurological Disorders and Stroke sponsored clinical trial of therapeutic hypothermia. PATIENTS: Sixty-five neonates with moderate to severe hypoxic ischemic encephalopathy within 6 hours after birth. INTERVENTIONS: Patients were randomized to normothermia of 37°C or systemic hypothermia of 33°C for 48 hours. MEASUREMENTS AND MAIN RESULTS: Complete and differential leukocyte counts and serum chemokines were measured every 12 hours for 72 hours. The hypothermia group had significantly lower median circulating total WBC and leukocyte subclasses than the normothermia group before rewarming, with a nadir at 36 hours. Only the absolute neutrophil count rebounded after rewarming in the hypothermia group. Chemokines, monocyte chemotactic protein-1 and interleukin-8, which mediate leukocyte chemotaxis as well as bone marrow suppression, were negatively correlated with their target leukocytes in the hypothermia group, suggesting active chemokine and leukocyte modulation by hypothermia. Relative leukopenia at 60-72 hours correlated with an adverse outcome in the hypothermia group. CONCLUSIONS: Our data are consistent with chemokine-associated systemic immunosuppression with hypothermia treatment. In hypothermic neonates, persistence of lower leukocyte counts after rewarming is observed in infants with more severe CNS injury.

Impact of depressive symptoms on future alcohol use in patients with co-occurring bipolar disorder and alcohol dependence: a prospective analysis in an 8-week randomized controlled trial of acamprosate.

BACKGROUND: Bipolar disorders and alcohol use disorders commonly co-occur, yet little is known about the proximal impact of bipolar symptoms on alcohol use in patients with this comorbidity. The present study examined the impact of depressive symptoms and alcohol craving on proximal alcohol use in patients with co-occurring bipolar disorder and alcohol dependence. METHODS: Data were collected during an 8-week randomized controlled trial of acamprosate for individuals with co-occurring bipolar disorder and alcohol dependence (n = 30). Depressive symptoms and alcohol craving were assessed biweekly using the Montgomery Asberg Depression Rating Scale (MADRS) and the Obsessive Compulsive Drinking Scale (OCDS), respectively. Daily alcohol use data were available via administration of the Time-line Follow-back interview at baseline and at subsequent weekly study visits. Correlational analyses and hidden Markov modeling were used to examine the prospective relationships between depressive symptoms, alcohol craving, and alcohol use. RESULTS: Depressive symptoms and alcohol craving were significantly correlated with proximal (i.e., 1 week later) alcohol use across a variety of alcohol consumption summary measures. In hidden Markov models, depressive symptoms (OR = 1.3, 95% credible interval = [1.1, 1.5]) and alcohol craving (OR = 1.6, 95% credible interval = [1.4, 1.9]) significantly predicted transitioning from a light to a heavy drinking state, or remaining in a heavy drinking state. CONCLUSIONS: The results from the present study suggest that depressive symptoms and alcohol craving increase proximal risk for alcohol use in individuals with co-occurring bipolar and alcohol use disorders.