Inferring the role of the microbiome on survival in patients treated with immune checkpoint inhibitors: causal modeling, timing, and classes of concomitant medications

BACKGROUND

The microbiome has been shown to affect the response to Immune Checkpoint Inhibitors (ICIs) in a small number of cancers and in preclinical models. Here, we sought to broadly survey cancers to identify those in which the microbiome may play a prognostic role using retrospective analyses of patients with advanced cancer treated with ICIs.

METHODS

We conducted a retrospective analysis of 690 patients who received ICI therapy for advanced cancer. We used a literature review to define a causal model for the relationship between medications, the microbiome, and ICI response to guide the abstraction of electronic health records. Medications with precedent for changes to the microbiome included antibiotics, corticosteroids, proton pump inhibitors, histamine receptor blockers, non-steroid anti-inflammatories and statins. We tested the effect of medication timing on overall survival (OS) and evaluated the robustness of medication effects in each cancer. Finally, we compared the size of the effect observed for different classes of antibiotics to taxa that have been correlated to ICI response using a literature review of culture-based antibiotic susceptibilities.

RESULTS

Of the medications assessed, only antibiotics and corticosteroids significantly associated with shorter OS. The hazard ratios (HRs) for antibiotics and corticosteroids were highest near the start of ICI treatment but remained significant when given prior to ICI. Antibiotics and corticosteroids remained significantly associated with OS even when controlling for multiple factors such as Eastern Cooperative Oncology Group performance status, Charlson Comorbidity Index score, and stage. When grouping antibiotics by class, β-lactams showed the strongest association with OS across all tested cancers.

CONCLUSIONS

The timing and strength of the correlations with antibiotics and corticosteroids after controlling for confounding factors are consistent with the microbiome involvement with the response to ICIs across several cancers.

Correction to: Outcomes associated with immune-related adverse events in metastatic non-small cell lung cancer treated with nivolumab: a pooled exploratory analysis from a global cohort

The original version of this article unfortunately contained a mistake. The second sentence of the section "irAEs and ICI efficacy" should read as.

Outcomes associated with immune-related adverse events in metastatic non-small cell lung cancer treated with nivolumab: a pooled exploratory analysis from a global cohort

BACKGROUND

Immune-related adverse events (irAEs) comprise a distinct spectrum of auto-inflammatory manifestations triggered due to immune checkpoint inhibitors (ICI). Current data on the association of irAEs with outcomes in NSCLC treated with nivolumab are limited.

METHODS AND OBJECTIVES

We pooled data from 531 metastatic NSCLC patients from five centers treated with nivolumab after failing platinum-based chemotherapy. The primary objective was to investigate the relationship between irAEs with clinical benefit to nivolumab as well as to elucidate patterns of irAE-related ICI discontinuations and their impact on survival.

RESULTS

33.0% (173/531) of patients treated with nivolumab were noted to have an irAE. Patients with irAEs had a significantly longer median PFS [6.1 vs. 3.1 months, HR 0.68 95% CI (0.55-0.85); p = 0.001] and OS [14.9 vs. 7.4 months, HR 0.66 95% CI (0.52-0.82); p < 0.001)] compared to those without irAEs. In multivariate analysis, the presence of irAEs showed a significantly better PFS [HR 0.69, 95% CI (0.55-0.87); p = 0.002] and a trend for better OS [HR 0.62, 95% CI (0.55-1.03); p = 0.057]. Patients with permanent ICI discontinuation secondary to index irAE had a significantly shorter median PFS [2.3 vs. 6.6 months, HR 1.74 95% CI (1.06-2.80); p = 0.02] and median OS [3.6 vs. 17.6 months; HR 2.61 95% CI (1.61-4.21); p < 0.001] compared to those that did not have permanent ICI discontinuation.

CONCLUSIONS

Our pooled exploratory analysis demonstrates improved clinical benefit to nivolumab in NSCLC patients experiencing irAEs. We also observed negative impact of irAE-related treatment discontinuation on survival in this group of patients.

Targeting BRAF Mutations in High-Grade Neuroendocrine Carcinoma of the Colon

Mutations in the RAS/RAF/MEK/ERK pathway leading to constitutive activation and uncontrolled cellular growth have been identified in various human malignancies, making this pathway a target for potential therapeutics. The activating BRAF^V600E mutation is one well-characterized oncogenic mutation that has been described and targeted with clinical success in various malignancies, including melanoma and hairy cell leukemia. Although BRAF-directed treatments have yielded clinical benefit in a subset of tumor types, such as melanoma, thyroid cancer, and lung cancer, BRAF inhibition fails to confer a clinical benefit in colon cancer. Identification of patients for whom BRAF inhibition may produce clinically meaningful outcomes is imperative. The incidence of BRAF mutations in neuroendocrine carcinoma (NEC) is estimated to be 5% to 10%. A recent case series demonstrated benefit in targeting the BRAF^V600E mutation in metastatic high-grade rectal NECs. Combination BRAF and MEK inhibition is known to yield improved outcomes compared with BRAF inhibition alone in melanoma. This report presents 2 patients with high-grade colorectal NECs who had different responses to treatment with combined BRAF/MEK inhibition after experiencing disease progression through first-line platinum-based chemotherapy. One patient experienced an excellent initial response to therapy before ultimately experiencing progression, and in the other patient initially had stable disease before eventually experiencing progression. These cases highlight the complicated role BRAF mutations play in gastrointestinal NECs, and the need for further research to identify not only patients who may benefit from BRAF-directed therapies but also strategies to avoid development of resistance.

Change in neutrophil to lymphocyte ratio during immunotherapy treatment is a non-linear predictor of patient outcomes in advanced cancers

BACKGROUND

The neutrophil to lymphocyte ratio (NLR) is known to be prognostic for patients with advanced cancers treated with immune checkpoint inhibitors (ICI), but has generally been evaluated as a single threshold value at baseline. We evaluated NLR at baseline and within first month during treatment in patients who received ICI for advanced cancer to evaluate the prognostic value of baseline and of changes from baseline to on-treatment NLR.

METHODS

A retrospective review of patients with advanced cancer treated with ICI from 2011 to 2017 at the Ohio State University was performed. NLR was calculated at the initiation of ICI and repeated at median of 21 days. Overall survival (OS) was calculated from the initiation of ICI to date of death or censored at last follow-up. Significance of Cox proportional hazards models were evaluated by log-rank test. Calculations were performed using the survival and survminer packages in R, and SPSS.

RESULTS

509 patients were identified and included in the analysis. Patients with baseline and on-treatment NLR < 5 had significantly longer OS (P < 0.001). The change in NLR overtime was a predictor of OS and was observed to be non-linear in nature. This property remained statistically significant with P < 0.05 after adjusting for age, body mass index, sex, cancer type, performance status, and days to repeat NLR measurement. Patients with a moderate decrease in NLR from baseline had the longest OS of 27.8 months (95% CI 21.8-33.8). Patients with significant NLR decrease had OS of 11.4 months (95% CI 6.1-16.7). Patients with a significant increase in NLR had the shortest OS of 5.0 months (95% CI 0.9-9.1).

CONCLUSIONS

We confirmed the prognostic value of NLR in patients with advanced cancer treated with ICIs. We found that change in NLR over time is a non-linear predictor of patient outcomes. Patients who had moderate decrease in NLR during treatment with ICI were found to have the longest survival, whereas a significant decrease or increase in NLR was associated with shorter survival. To our knowledge, this is the first study to demonstrate a non-linear change in NLR over time that correlates with survival.

Cabozantinib in advanced non-clear-cell renal cell carcinoma: a multicentre, retrospective, cohort study

BACKGROUND

Cabozantinib is approved for patients with metastatic renal cell carcinoma on the basis of studies done in clear-cell histology. The activity of cabozantinib in patients with non-clear-cell renal cell carcinoma is poorly characterised. We sought to analyse the antitumour activity and toxicity of cabozantinib in advanced non-clear-cell renal cell carcinoma.

METHODS

We did a multicentre, international, retrospective cohort study of patients with metastatic non-clear-cell renal cell carcinoma treated with oral cabozantinib during any treatment line at 22 centres: 21 in the USA and one in Belgium. Eligibility required patients with histologically confirmed non-clear-cell renal cell carcinoma who received cabozantinib for metastatic disease during any treatment line roughly between 2015 and 2018. Mixed tumours with a clear-cell histology component were excluded. No other restrictive inclusion criteria were applied. Data were obtained from retrospective chart review by investigators at each institution. Demographic, surgical, pathological, and systemic therapy data were captured with uniform database templates to ensure consistent data collection. The main objectives were to estimate the proportion of patients who achieved an objective response, time to treatment failure, and overall survival after treatment.

FINDINGS

Of 112 identified patients with non-clear-cell renal cell carcinoma treated at the participating centres, 66 (59%) had papillary histology, 17 (15%) had Xp11.2 translocation histology, 15 (13%) had unclassified histology, ten (9%) had chromophobe histology, and four (4%) had collecting duct histology. The proportion of patients who achieved an objective response across all histologies was 30 (27%, 95% CI 19-36) of 112 patients. At a median follow-up of 11 months (IQR 6-18), median time to treatment failure was 6·7 months (95% CI 5·5-8·6), median progression-free survival was 7·0 months (5·7-9·0), and median overall survival was 12·0 months (9·2-17·0). The most common adverse events of any grade were fatigue (58 [52%]), and diarrhoea (38 [34%]). The most common grade 3 events were skin toxicity (rash and palmar-plantar erythrodysesthesia; five [4%]) and hypertension (four [4%]). No treatment-related deaths were observed. Across 54 patients with available next-generation sequencing data, the most frequently altered somatic genes were CDKN2A (12 [22%]) and MET (11 [20%]) with responses seen irrespective of mutational status.

INTERPRETATION

While we await results from prospective studies, this real-world study provides evidence supporting the antitumour activity and safety of cabozantinib across non-clear-cell renal cell carcinomas. Continued support of international collaborations and prospective ongoing studies targeting non-clear-cell renal cell carcinoma subtypes and specific molecular alterations are warranted to improve outcomes across these rare diseases with few evidence-based treatment options.

FUNDING

None.

The reluctant innovator: orangutans and the phylogeny of creativity

Young orangutans are highly neophobic, avoid independent exploration and show a preference for social learning. Accordingly, they acquire virtually all their learned skills through exploration that is socially induced. Adult exploration rates are also low. Comparisons strongly suggest that major innovations, i.e. behaviours that have originally been brought into the population through individual invention, are made where ecological opportunities to do so are propitious. Most populations nonetheless have large innovation repertoires, because innovations, once made, are retained well through social transmission. Wild orangutans are therefore not innovative. In striking contrast, zoo-living orangutans actively seek novelty and are highly exploratory and innovative, probably because of positive reinforcement, active encouragement by human role models, increased sociality and an expectation of safety. The explanation for this contrast most relevant to hominin evolution is that captive apes generally have a highly reduced cognitive load, in particular owing to the absence of predation risk, which strongly reduces the costs of exploration. If the orangutan results generalize to other great apes, this suggests that our ancestors could have become more curious once they had achieved near-immunity to predation on the eve of the explosive increase in creativity characterizing the Upper Palaeolithic Revolution.

Therapeutic impact and timing of gastrointestinal malignancy genomic profiling: A single-institution experience

584

Background: Tumor genomic profiling has become critical in the identification of targeted therapeutic options for patients (pts) with advanced malignancies. Mutational frequencies and their therapeutic importance vary among tumor types. This analysis was undertaken to characterize the landscape of genomic alterations in gastrointestinal (GI) malignancies found in a large academic institutional practice, and to determine the frequency of alteration-specific targeted therapy selection based on genomic profiling. Methods: Adult pts with GI malignancies presenting to the Ohio State University Comprehensive Cancer Center oncology clinics were offered next generation sequencing through FoundationOne testing as part of routine clinical care. Institutional review board approval was obtained to retrospectively analyze results from FoundationOne testing performed between 2012 and 2015. Results: 265 pts with GI malignancies underwent successful genomic profiling. 1205 genomic alterations were found, with an average of 4.5 per tumor (range 0-20); 365 (30%) of these were potentially actionable and most often found in colorectal or gastroesophageal tumors. 14 pts (5.3%) had actionable alterations in MET, CDKN2A/B, FGFR2, KRAS, BRAF, or NF2 that led to enrollment in genotype-directed clinical trials or off label use of targeted therapies beyond standard of care. Pt performance status at the time of genomic alteration identification was a significant factor in precluding genotype-directed therapy. One variant of unknown significance involving FGFR2 identified at initial testing subsequently became actionable and led to pt enrollment on a clinical trial. One pt with rectal cancer was found to have a KRAS wild-type and BRAF mutant primary but KRAS mutant and BRAF wild-type liver metastasis. Conclusions: Genomic profiling of GI malignancies through next generation sequencing is feasible and can lead to genotype-directed therapy selection; however, it should be considered early in the pt’s course to optimize use of targeted therapies through clinical trials. Consideration should be given to serial tumor testing to identify emerging genomic alterations for optimal therapy selection.

Comparison of particulate number concentrations in three Central European capital cities

Number size distributions of atmospheric aerosol particles in the mobility diameter range from 10 to 1000 nm were determined in Budapest, Prague and Vienna for a one-year-long period. Particle number concentrations in various size fractions, their diurnal and seasonal variations, mean size distributions and some properties of new particle formation events were derived and compared. Yearly median particle number concentrations for Budapest, Prague and Vienna were 10.6×10(3), 7.3×10(3) and 8.0×10(3) cm(-3). Differences were linked to the different pollution levels of the cities, and to diverse measurement environments and local conditions. Mean contributions of ultrafine particles (particles with a mobility diameter <100 nm) to the total number concentration were 80%, 84% and 74% for Budapest, Prague and Vienna, thus these particles represent an overwhelming share of all particles in each city. Seasonal variation of particle number concentrations was not obvious. Diurnal variations of particles with a diameter between 100 and 1000 nm (N(100-1000)) exhibited similar shape for the cities, which was related to the time-activity pattern of inhabitants and regional influences. The structure of the diurnal variation for ultrafine particles was also similar. It contained a huge morning peak in each city which was explained by emissions from vehicular traffic. The second peak was shifted from afternoon rush hours to late evenings as a result of the daily cycling in meteorological parameters. The character of the measurement site also influenced the diurnal variation. Diurnal variation of the mean ratio of ultrafine particles to N(100-1000) clearly revealed the presence and importance of new particle formation and subsequent growth in urban environments. Nucleation frequencies in Budapest and Prague were 27% and 23%, respectively on a yearly time scale. They showed a minimum in winter for both places, while the largest nucleation activity was observed in spring for Budapest, and in summer for Prague.

Long-term study of cloud condensation nuclei (CCN) activation of the atmospheric aerosol in Vienna

During a total of 11 months, cloud condensation nuclei (CCN at super-saturation S 0.5%) and condensation nuclei (CN) concentrations were measured in the urban background aerosol of Vienna, Austria. For several months, number size distributions between 13.22 nm and 929 nm were also measured with a scanning mobility particle spectrometer (SMPS). Activation ratios (i.e. CCN/CN ratios) were calculated and apparent activation diameters obtained by integrating the SMPS size distributions. Variations in all CCN parameters (concentration, activation ratio, apparent activation diameter) are quite large on timescales of days to weeks. Passages of fronts influenced CCN parameters. Concentrations decreased with the passage of a front. No significant differences were found for fronts from different sectors (for Vienna mainly north to west and south to east). CCN concentrations at 0.5% S ranged from 160 cm(-3) to 3600 cm(-3) with a campaign average of 820 cm(-3). Activation ratios were quite low (0.02-0.47, average: 0.13) and comparable to activation ratios found in other polluted regions (e.g. Cubison et al., 2008). Apparent activation diameters were found to be much larger (campaign average: 169 nm, range: (69-370) nm) than activation diameters for single-salt particles (around 50 nm depending on the salt). Contrary to CN concentrations, which are influenced by source patterns, CCN concentrations did not exhibit distinct diurnal patterns. Activation ratios showed diurnal variations counter-current to the variations of CN concentrations.

Characterizing the performance of two optical particle counters (Grimm OPC1.108 and OPC1.109) under urban aerosol conditions

The performance of Grimm optical particle counters (OPC, models 1.108 and 1.109) was characterized under urban aerosol conditions. Number concentrations were well correlated. The different lower cut-off diameters (0.25 and 0.3 μm) give an average difference of 23.5%. Both detect less than 10% of the total particle concentration (0.01-1 μm; Differential Mobility Analyzer), but in the respective size ranges, differences are <10%. OPC number size distributions were converted to mass concentrations using instrument-specific factors given by the manufacturer. Mass concentrations for OPC1.108 were 60% higher than for OPC1.109 and (in case of OPC1.109) much lower than those measured with an impactor in the relevant size range or a TSP filter. Using the C-factor correction suggested by the manufacturer, OPC1.109 underestimated mass concentrations by 21% (impactor) and by about 36% (TSP filter), which is in the range of comparability of co-located different mass concentration methods (Hitzenberger, Berner, Maenhaut, Cafmeyer, Schwarz, & Mueller et al., 2004).

Atonal homolog 1 is required for growth and differentiation effects of notch/gamma-secretase inhibitors on normal and cancerous intestinal epithelial cells

BACKGROUND & AIMS

The atonal homolog 1 (Atoh1) transcription factor is required for intestinal secretory (goblet, Paneth, enteroendocrine) cell differentiation. Notch/gamma-secretase inhibitors (GSIs) block proliferation and induce secretory cell differentiation in the intestine. We used genetic analyses of mice to determine whether Atoh1 mediates the effects of GSIs in normal and cancerous intestinal epithelia.

METHODS

We studied mice with intestine-specific disruption of Atoh1 (Atoh1(Deltaintestine)), the adenomatosis polyposis coli (APC)(min) mutation, both mutations (Atoh1(Deltaintestine); APC(min)), or littermate controls; mice were given GSI or vehicle. Colorectal cancer (CRC) cell lines were treated with GSI or vehicle and with small hairpin RNAs to reduce ATOH1. Differentiation and homeostasis were assessed by protein, RNA, and histologic analyses.

RESULTS

GSIs failed to induce secretory cell differentiation or apoptosis or decrease proliferation of Atoh1-null progenitor cells, compared with wild-type cells. Exposure of APC(min) adenomas to GSIs decreased proliferation and increased secretory cell numbers in an Atoh1-dependent manner. In CRC cells treated with GSI, ATOH1 levels were correlated inversely with proliferation. ATOH1 was required for secretory cell gene expression in cell lines and in mice.

CONCLUSIONS

ATOH1 is required for all effects of GSIs in intestinal crypts and adenomas; Notch has no unique function in intestinal progenitors and cancer cells other than to regulate ATOH1 expression. Reducing ATOH1 activity might mitigate intestinal toxicity from systemic GSI therapy for nonintestinal diseases. Among gastrointestinal malignancies, ATOH1 mediates the effects of GSIs, so ATOH1 expression levels might predict responses to these inhibitors. We propose that only the subset of CRCs that retain ATOH1 expression will respond to GSIs.

Neurological decompression illness and hematocrit: analysis of a consecutive series of 200 recreational scuba divers

Neurological complications are common in recreational divers diagnosed with decompression illness (DCI). Prior reports suggest that hemoconcentration, with hematocrit values of 48 or greater, increase the risk for more severe and persistent neurological deficits in divers with DCI. Herein we describe our experience with neurological DCI and hematocrit values in a large series of consecutively treated divers. We performed a retrospective chart review of 200 consecutive recreational divers that received treatment for DCI. Standard statistical analyses were performed to determine if there were any significant relationships between diving-related or demographic parameters, neurological manifestations, and hematocrit. In 177 of the 200 divers (88.5%), at least one manifestation of neurological DCI (mild, moderate, or severe) was present. The median hematocrit value was 43, for both male and female divers, with a range of 30 to 61. Hematocrit values did not correlate with diver age or level of diving experience. In male divers, the hematocrit did not correlate with neurological symptoms, including the sub-group with values of 48 or greater. In contrast, female divers with hematocrit values of 48 or greater were significantly more likely to develop motor weakness (p=0.002, Fisher's exact test) and an increased number of severe sensory symptoms (p=0.001, Kendall's tau statistic). Neurological complications are common in recreational divers treated for DCI. Hematocrit values of 48 or higher were correlated with the presence of motor weakness and severity of sensory symptoms in female divers. The hematocrit did not correlate with neurological DCI in male divers.

Neurological manifestations of decompression illness in recreational divers - the Cozumel experience

Neurological signs and symptoms are common in recreational divers with decompression illness (DCI). The spectrum of neurological manifestations, temporal profile, and laboratory findings are described in a large series of 200 consecutive recreational divers treated for DCI. The Hyperbaric Medicine Unit charts of 200 recreational divers treated for DCI were reviewed and analyzed. The cohort was mainly male, with a median age of 40 years, and quite experienced, with a median of 100 prior dives. In 44 divers (22%) a rapid ascent was documented. The median time to onset of neurological symptoms was 60 minutes after surfacing. One hundred seventy-seven of 200 divers (88.5%) had at least one symptom of neurological DCI at presentation. The most common neurological manifestations were paresthesia, dysesthesia, incoordination, motor weakness, and dizziness. Paresthesias were associated with significantly younger (p = 0.003) and less experienced (p = 0.03) divers. Similar but less significant correlations were noted for dysesthesias. Female divers were significantly more likely to experience painful skin symptoms (p < 0.001). Neurological manifestations are common in recreational divers treated for DCI. Neurological DCI and paresthesias are more likely to occur in younger and less experienced divers.

Phase III randomized multicenter trial of surgical resection, BCNU-impregnated wafers, and irradiation versus surgical resection and irradiation alone for treatment of operable, solitary brain metastasis from systemic cancer

11513

Background: Metastatic brain tumors (MBT) are the most frequent complication of systemic cancer. With conventional radiotherapy, survival remains poor, ranging from 24 to 32 weeks. Recent randomized trials suggest that surgical resection and irradiation of solitary MBT can extend survival and improve neurological quality of life. However, the role of chemotherapy remains unclear. A phase I/II trial demonstrated that interstitial chemotherapy with BCNU-impregnated wafers was well tolerated in this cohort, with an extended median survival and infrequent local recurrences. Methods: A randomized, multicenter phase III trial was begun to evaluate the ability of BCNU-impregnated wafers to improve survival and local time to progression in comparison to surgical resection and irradiation alone, with an expected accrual of 170 patients. Eligible patients were adults with systemic cancer of the lung or breast, with a solitary, accessible MBT that did not cross the midline or violate the ventricular system. Results: A total of 22 patients (female - 14; 20 with lung cancer), median age 60 years (range 39–77), were enrolled and randomized before the study was closed due to slow accrual. Each patient had undergone maximal surgical resection of the MBT and radiation therapy (35 Gy); wafers were placed in 12 patients (range 2–8 wafers). The median overall survival for the wafer and non-wafer groups were 35.0 and 47.4 weeks, respectively (log rank test, p = 0.54), with a 6-month survival rate of 67% and 56%, respectively (Fishers exact test, p = 0.67). Wafer placement was well tolerated. Conclusions: In this small cohort limited by slow accrual, the use of BCNU-impregnated wafers did not improve survival over surgical resection and irradiation alone. The wafers were well tolerated and did not adversely impact on quality of life. Although animal studies and phase I/II data are suggestive of activity, a large, multicenter, phase III comparative trial will be necessary to determine the efficacy of BCNU-impregnated wafers in patients with solitary, resectable MBT.

[Table: see text]

Patients on chronic peritoneal dialysis for ten years or more in North America

Thirty-six patients on peritoneal dialysis (PD) for more than ten years in six North American centers were analyzed retrospectively. In the six centers, the percentage of patients surviving for more than ten years varied between 0.8% and 7.3%. The study group included 27 females and 9 males aged 38.6 +/- 14.2 years [mean +/- standard deviation (SD)] at the start of treatment. Of the 36 patients, 28 were Caucasian. The most common cause of end-stage renal disease (ESRD), present in 12 patients, was chronic glomerulonephritis. Only 4 patients had diabetes. At the beginning of the study, 19 patients had hypertension (the most common comorbid condition); 11 had no comorbid conditions at the start. Creatinine clearance at the start was 4.12 +/- 3.5 mL per minute, and the mean duration to anuria was 51 +/- 25 months. Mean initial body weight was 55 +/- 9 kg, and mean body surface area was 1.5 +/- 0.2 m2. Serum albumin levels showed an increase from 33.8 +/- 3.6 g/L at the start of the study to 38.2 +/- 3.9 g/L at the end. Hospitalization rate was low at 0.5 +/- 0.3 admissions per patient-year, and duration of hospitalization was 4.8 +/- 3.7 days per patient-year. Peritonitis was the most common cause of hospitalization. The mean peritonitis rate was 1 episode every 52 +/- 48 patient-months. There were 36 catheter changes in 18 patients; 16 patients had a single PD catheter throughout the period of study. Autonomous hyperparathyroidism was the most common long-term complication. At the end of the study period, 11 patients were still on PD, 9 had died, 5 had been transferred to hemodialysis (HD), 1 was alive with a functioning allograft, and 1 was lost to follow-up. We conclude that patients who survive longer than ten years on PD are most likely to be young Caucasian females, small in body size, who are non diabetic, with few comorbid conditions. These long-term survivors have few hospitalizations, and their peritonitis rate is low. In this group of patients, severe autonomous hyperparathyroidism is the most common long-term complication.

Comparison of intraperitoneal and subcutaneous epoetin alfa in peritoneal dialysis patients

OBJECTIVE

To compare the efficacy of intraperitoneal (i.p.) and subcutaneous (s.c.) administration of epoetin alfa in patients receiving peritoneal dialysis (PD).

DESIGN

A 32-week prospective, randomized, cross-over experimental design.

SETTING

Two university-based outpatient PD centers.

PATIENTS

Twenty adult PD patients receiving stable doses of s.c. epoetin alfa enrolled in the study. Thirteen patients completed 32 weeks of follow-up.

INTERVENTION

Patients were randomly assigned to receive either s.c. or i.p. epoetin alfa at the start of the study. Dose adjustments were made to maintain baseline hematocrit +/- 3 percentage points. Following 16 weeks of treatment, patients crossed over to the other route of administration for an additional 16 weeks. Intraperitoneal epoetin alfa was administered into an empty peritoneal cavity for approximately 8 hours before resuming dialysis. End-of-study i.p. epoetin alfa doses required to maintain target hematocrit were given twice weekly (n = 1), once weekly (n = 11), or once every other week (n = 1). All patients received iron supplements to maintain or exceed prestudy iron parameters.

MAIN OUTCOME MEASURE

Prior to the study, the primary outcome measure was defined as the difference in epoetin alfa dose between i.p. and s.c. administration.

RESULTS

Thirteen patients completed the study. The area under the dosing-requirement curve for i.p. epoetin alfa was larger than for s.c. administration (p = 0.0029), and the slope of the 16-week dose-requirement curve was greater for i.p. administration (p = 0.017), suggesting greater dose stability for s.c. administration. Paired analysis indicated greater i.p. intrapatient dose requirements (p < 0.0001). The mean difference in s.c. versus i.p. doses was 5000 +/- 1510 units per week. Some patients required escalating i.p. doses to maintain target hematocrit values. Iron administration and iron stores were similar in both groups.

CONCLUSION

Intraperitoneal epoetin alfa may be a suitable alternative for some patients for whom s.c. dosing is undesirable. Large i.p. versus s.c. dosing differences noted in a few patients are unexplained, but may result from interpatient variability in i.p. epoetin alfa absorption. Intraperitoneal dosing into an empty peritoneum can be done safely and effectively.

Eyelid resurfacing

BACKGROUND AND OBJECTIVE

Laser resurfacing of eyelids was examined in a series of experiments designed to measure beam parameters, surface temperatures, ablation characteristics, thermal damage, tissue responses and clinical outcomes. These data were collected for the purpose of developing a logical basis for clinical dosimetry.

STUDY DESIGN

All experiments were conducted with similar short-pulse CO(2) lasers (TruPulse, Albuquerque, NM) where the beam had been carefully characterized and calibrated. The chronological sequence examined begins with the photophysical laser/tissue interactions during the first few microsec of irradiation and ends with an evaluation of the efficacy of wrinkle reduction nine months after treatment.

RESULTS

Eyelid tissue removed by the first and second passes consisted mostly of epidermis with about 38 microm of thermal damage into the papillary dermis. Erythema resolved within four weeks and most patients experienced 70-100% wrinkle reduction by nine months.

CONCLUSION

A layer of contracted dermal scar tissue that replaced the thermally challenged zone in the dermis is identified as the substrate for wrinkle reduction. The data support the following dosimetry for periorbital wrinkle reduction: One pass 4-6 J/cm(2) (350-500 mJ into a 3 x 3 mm spot). A second treatment after 9-12 months may be more beneficial than a second pass.

Treatment of malnutrition with 1.1% amino acid peritoneal dialysis solution: results of a multicenter outpatient study

A peritoneal dialysis (PD) solution containing 1.1% amino acids as the osmotic agent was evaluated in a 3-month randomized, prospective, open-label study in malnourished PD patients. Patients in the treatment group (DAA) received one or two exchanges daily with the amino acid solution, depending on tolerance, in place of glucose solutions. Controls (DD) received their usual therapy with glucose dialysate. Fifty-four DAA and 51 DD patients completed the study. In DAA, but not in DD patients, there was a significant increase at month 3 in serum insulin-like growth factor-1 (IGF-1) levels and significant decreases in serum potassium (all 3 months) and inorganic phosphorus levels (months 1 and 3), indicating a general anabolic response. Prealbumin and transferrin levels were significantly increased in DAA but not in DD patients at month 1, but the groups did not differ at months 2 and 3. In patients with baseline albumin levels less than 3.5 g/dL (bromcresol green [BCG] method), DAA patients showed increases in albumin, transferrin (months 1 and 2), and prealbumin levels (all 3 months) relative to baseline values, whereas these serum protein levels were unchanged in DD patients, although the changes from baseline did not differ between groups. In this subgroup, midarm muscle circumference (MAMC) did not change in DD or DAA patients. In patients with baseline albumin levels of 3.5 g/dL or greater, DD patients had decreases in albumin and total protein levels at all 3 months and in prealbumin levels at months 1 and 2, relative to baseline. In DAA patients, there were fewer changes in serum proteins. MAMC increased significantly from baseline in DAA but not in DD patients, although changes from baseline did not differ between DAA and DD groups. DAA patients showed no changes in peritoneal membrane transport characteristics. The results indicate that treatment with one or two exchanges daily of this amino acid-based PD solution is safe and provides nutritional benefit for malnourished PD patients.

Field test to evaluate telepathology in telemedicine

Telepathology is currently performed only on prototype systems. The application of telepathology consultations differs from the conventional procedure because of the technical and cost restrictions. This paper outlines technical concepts and the principal hardware and software modules necessary for telemicroscopy equipment. A field test to gather information concerning the user needs and to evaluate parameters of telepathology consultation sessions is reported.

Peritoneal dialysis kinetic modeling: validation in a multicenter clinical study

OBJECTIVE

To clinically validate the use of a computer-based kinetic model for peritoneal dialysis (PD) by assessing the level of agreement between measured and modeled values of urea and creatinine clearances and ultrafiltration (UF).

DESIGN

An open multicenter observational study.

PATIENTS

There were 111 adult continuous ambulatory peritoneal dialysis (CAPD) patients (47 female, 64 male) in four centers. All patients underwent a four-hour peritoneal equilibration test (PET) using 2.5% dextrose but with variable fill volumes (range: 1-3 L). Patients with a residual renal function greater than 10 mL/min were excluded.

MAIN OUTCOME MEASURES

Correlations and limits of agreement between measured and modeled values of total weekly urea KT/V, total weekly normalized creatinine clearance (L/week/1.73 m2), daily drain volume (L), net ultrafiltration (L), daily peritoneal urea clearance (L/day), and daily peritoneal creatinine clearance (L/day). Measured values were obtained from 24-hour urine and dialysate collections while modeled values were based on results from the PET in combination with the PD ADEQUEST kinetic program.

RESULTS

The results show there is excellent agreement between measured and modeled urea KT/V and creatinine clearances, with concordance correlations of 0.94 and 0.92, respectively. Given the excessive variation and limited range in ultrafiltration values, the concordance correlation between measured and modeled UF was only 0.50. In terms of daily peritoneal clearances and ultrafiltration, the level of precision (i.e., standard deviation) in the differences between modeled and measured values is +/- 1.05 L/day for urea clearance +/- 1.03 L/day for creatinine clearance, and +/- 0.919 L/day for ultrafiltration. By contrast, the level of precision (i.e., standard deviation) in the differences between two measured values is estimated to be +/- 0.979 L/day for urea clearance, +/- 0.802 L/day for creatinine clearance, and +/- 0.707 L/day for ultrafiltration. Defining the limits of clinical agreement to be +/- 2 standard deviations of the differences between two clinically measured 24-hour clearances (or ultrafiltration), we find that 94% of the modeled urea clearances, 87% of the modeled creatinine clearances, and 86% of the modeled ultrafiltration values fall within the limits of clinical agreement.

CONCLUSION

Data for a carefully performed PET and overnight exchange can, in combination with a scientifically validated kinetic model, provide clinicians with a powerful mathematical tool for use in CAPD dialysis prescription management. Although not intended to replace actual measurements, kinetic modeling can prove useful as a means for predicting clearances for various alternative prescriptions and perhaps also as a means for checking certain types of noncompliance.

Racial differences in the incidence of end-stage renal disease

OBJECTIVE

To examine trends in the incidence of treated end-stage renal disease (ESRD) and variations between blacks and whites.

DESIGN

Retrospective record reviews of all new patients > or = 15 years starting chronic dialysis during 1980-1988 at the Piedmont Dialysis Center, Forsyth County, North Carolina.

RESULTS

The cumulative nine-year incidence rate for hypertensive ESRD was 570 per million, and for diabetic ESRD 497 per million. Among men, hypertensive ESRD accounted for the largest proportion of cases (39.2% and 28.4%, blacks and whites respectively), while diabetic ESRD contributed 33.9% of black female cases and 24.4% of white female cases. Compared to whites, blacks were at significantly increased risk, with an adjusted risk odds ratio (OR) of 4.4 (95% confidence interval (CI) 3.5-6.0) for all causes combined, 6.0 (CI 3.9-9.0) for hypertensive renal disease, 6.0 (CI 3.8-9.3) for renal disease due to insulin-dependent diabetes mellitus, and 12.2 (CI 6.9-21.7) due to non-insulin dependent diabetes mellitus (NIDDM). The greatest risk among blacks was seen in the 55-64 year age group, with ORs of 9.1 for all causes combined and 30.6 for hypertensive renal disease. The OR for renal disease due to NIDDM for black versus white women was 20.0 (CI 9.5-41.7). Compared to 1980, 1981, 1982 and 1983, increased incidence rates were seen in each year after 1984.

CONCLUSION

These findings show even greater excess risk of ESRD among blacks than previously reported. The majority of the excess risk is seen for ESRD due to hypertension and diabetes, especially NIDDM. The reasons for the increased risk among blacks, and for the increasing incidence rates of ESRD are not known.

The importance of monitoring dialysis adequacy in chronic peritoneal dialysis

The case of a patient who was noted to be malnourished but improved after his dialysis dose was increased is presented. This case and the discussion that follows emphasize the importance of proactively monitoring peritoneal dialysis adequacy and nutritional intake, supporting the notion that the dose of peritoneal dialysis is a major determinant of appetite and, consequently, of nutritional status. In the clinical setting, this influence is best indicated by changes in the serum albumin level and ultimately in long-term patient survival. The case discussion reviews the major principles and supporting literature, describing how we target peritoneal dialysis delivery and optimize nutritional status in an effort to reduce morbidity and mortality.

Multicenter trial of erythropoietin in patients on peritoneal dialysis

A randomized, double-blind, placebo-controlled, multicenter trial was performed to assess the safety and efficacy of subcutaneous recombinant erythropoietin (EPO) in peritoneal dialysis patients. Seventy-eight patients were randomized to receive EPO and 74 received placebo during the first 12 wk. After this, placebo patients with hematocrit less than 32% entered the EPO maintenance phase along with the initial EPO patients. Hematocrit rose significantly in the EPO group from 23.8 to 32% after 6 wk, and this was sustained at 33.7% at 12 wk. In the placebo group, the prestudy hematocrit was 23.8% as well, and no significant change in hematocrit occurred over 12 wk. Concomitant with the rise in hematocrit, transfusion requirements fell only in the EPO group. Eighty-eight percent of patients receiving EPO had their anemia ameliorated by Week 12 of the study. There was a wide range of dosage requirements during the maintenance phase, ranging from 8,000 U thrice weekly to 4,000 U every other week. Adverse events after EPO were similar to those seen in hemodialysis patients given this agent, with hypertension developing or worsening in 55% of EPO patients during the initial 12 wk of therapy. Blood pressure was more likely to rise in patients with hypertension before receiving EPO. EPO is safe and effective in peritoneal dialysis patients, as it is in hemodialysis patients. Other than a rise in blood pressure, which is manageable with antihypertensives and ultrafiltration with dialysis, no serious side effects are seen. The optimal target hematocrit, effects of anemia improvement on quality of life, and end-organ (heart, brain) effects of anemia improvement in this patient population require further study.

Quantitative gas transfer into and out of circulating venous blood by means of an intravenacaval oxygenator

The volume of O2 and CO2 transferred into/out circulating venous blood by various sized IVOX devices has been assessed by ex vivo and in vivo animal experiments and by reviewing the gas transfer data collected from the first 20 human ARDS patients studied during Phase I of the IVOX clinical trials. Data from these assessments indicate that oxygen transfer through the size 5 IVOX ranges from 15.4 to 18.0 cc/min; through the size 6 IVOX ranges from 22.8 to 35.5 cc/min; through the size 7 IVOX ranges from 28.5 to 66.7 cc/min; through the size 8 IVOX ranges from 34.9 to 66.3 cc/min; through the size 9 IVOX ranges from 45.9 to 115.7 cc/min; through the size 10 IVOX ranges from 52.9 to 133 cc/min. Quantitative carbon dioxide transfer through the various size IVOX devices closely follows the quantitative oxygen transfer achieved by IVOX. These quantitative data provide valuable information to clinicians considering using IVOX to augment the inadequate gas transfer existing in patients with acute, potentially reversible respiratory failure. They indicate IVOX transfers clinically significant quantities of O2 into and CO2 out of circulating venous blood in an intact subject without involving the subjects natural lungs.

Usefulness of peritoneal fluid amylase levels in the differential diagnosis of peritonitis in peritoneal dialysis patients

Peritonitis continues to be a major cause of morbidity in peritoneal dialysis patients despite recent technological advances (Y systems) that have reduced peritonitis rates to much more acceptable levels. Most of the time when a peritoneal dialysis patient presents with peritonitis, it is infectious in origin. However, these patients occasionally develop other intra-abdominal pathology that requires more intensive medical care or, at times, surgical intervention. To help in the early differential diagnosis of the cause of peritonitis in these patients, peritoneal fluid amylase levels were prospectively obtained from 50 patients presenting to the hospital with peritonitis. Thirty-nine of them had typical infectious peritonitis, and their mean peritoneal fluid amylase level was 11.1 (range, 0 to 90). Six patients had pancreatitis and a mean peritoneal fluid amylase level of 550 U/L (range, 100 to 1,140 U/L). Five patients were found to have other intra-abdominal pathology, and their mean peritoneal fluid amylase level was 816 U/L (range, 142 to 1,746 U/L). In patients who did not respond to initial therapy, sequential peritoneal fluid amylase levels did not increase in patients with typical infectious peritonitis whereas it did increase in patients with other intra-abdominal pathology. In conclusion, it was found that peritoneal fluid amylase levels were helpful in the differential diagnosis of peritonitis in these patients. An elevated level (greater than 100 U/L) differentiated those patients with other intra-abdominal causes of peritonitis from those with typical infectious peritonitis.

Serum and peritoneal fluid amylase levels in CAPD. Normal values and clinical usefulness

The mean serum amylase of 42 asymptomatic CAPD patients was elevated but was not significantly different from that of a group of chronic hemodialysis patients. Serum amylase levels in CAPD patients with peritonitis were not elevated with respect to asymptomatic patients. Amylase activity was not detectable in the peritoneal fluid of 38/42 asymptomatic patients and 6/13 peritonitis patients and was present at low levels in the other 11 patients. Patients with other abdominal conditions (pancreatitis, cholecystitis and small bowel perforation) had very marked elevations of serum and/or peritoneal fluid amylase which differentiated them from the asymptomatic and peritonitis patients. Although hyperamylasemia is common in asymptomatic CAPD patients and in those with peritonitis, measurement of serum and peritoneal fluid amylase levels is useful in the evaluation of CAPD patients presenting with abdominal symptoms.

Morbidity survey of U.S. oil shale workers employed during 1948-1969

The health status of 325 oil shale workers employed at the Anvil Points, Colorado, demonstration facility from 1948 to 1969 was evaluated. As a comparison population, 323 Utah coal miners frequency matched for age were studied. The prevalence of respiratory symptoms among oil shale workers who smoked were similar to the coal miners who smoked, although nonsmoking oil shale workers had fewer symptoms compared to nonsmoking coal workers. Four cases of skin cancers were found on the oil shale workers and eight cases in the controls. Similar numbers of nevi, telangiectasiae, possible pitch warts, pigment changes (solar/senile lentigo), and papillomata (seborrheic keratoses and skin tags) were seen in both groups, while actinic keratoses were more frequent in the oil shale workers. The prevalence of actinic keratoses was significantly associated with oil shale work after allowing for age, sun exposure, and other exposures. The prevalence of pulmonary cytology metaplasia was associated with years of production work in oil shale among both smokers and exsmokers. More of the oil shale workers had atypical cells in the urine, but the excess was mostly found among exsmokers. Although these workers had short-term and limited oil shale exposure work exposure, we recommend that medical surveillance of oil shale workers consider the skin, respiratory, and urinary systems for special observation.