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Objective: Health disparities may be driven by hospital-level factors. We assessed whether racial and ethnic composition of populations hospitals serve explain or modify disparities in hospital outcomes of children with systemic lupus erythematosus (SLE)., Methods: In this retrospective cohort study of patients 5 to 26 years old with SLE at 47 children's hospitals in the Pediatric Health Information System (2006-2021), race and ethnicity were assessed at the patient level and hospital level (proportion of total admissions composed of Black or Hispanic patients, respectively). Outcomes included intensive care unit (ICU) admission or adverse renal outcome (end-stage renal disease, dialysis, or transplant) during follow-up. We estimated racial and ethnic disparities, adjusted or stratified by hospital racial or ethnic composition., Results: Of 8,125 patients with SLE, 2,293 (28%) required ICU admission, and 698 (9%) had an adverse renal outcome. Black and non-Hispanic White disparities in ICU admission were observed only at hospitals serving higher proportions of Black patients (odds ratio [OR] 1.29, 95% confidence interval [95% CI] 1.04-1.59 vs OR 1.07, 95% CI 0.83-1.38). Larger Black and non-Hispanic White disparities in adverse renal outcomes were observed at hospitals with higher Black racial composition (OR 2.0, 95% CI 1.4-2.8 vs OR 1.7, 95% CI 1.1-2.4). Conversely, Hispanic versus non-Hispanic disparities in renal outcomes persisted after adjustment for hospital-reported Hispanic ethnic composition but were observed only at hospitals with lower proportions of Hispanic patients., Conclusion: Worse Black and White disparities in SLE outcomes are observed at children's hospitals serving more Black children, whereas distinct patterns are observed for Hispanic and non-Hispanic disparities. Reporting of hospital characteristics related to populations served is needed to identify modifiable drivers of hospital-level variation., (© 2024 American College of Rheumatology.)

Background: In patients with newly diagnosed multiple myeloma, the effect of adding autologous stem-cell transplantation (ASCT) to triplet therapy (lenalidomide, bortezomib, and dexamethasone [RVD]), followed by lenalidomide maintenance therapy until disease progression, is unknown., Methods: In this phase 3 trial, adults (18 to 65 years of age) with symptomatic myeloma received one cycle of RVD. We randomly assigned these patients, in a 1:1 ratio, to receive two additional RVD cycles plus stem-cell mobilization, followed by either five additional RVD cycles (the RVD-alone group) or high-dose melphalan plus ASCT followed by two additional RVD cycles (the transplantation group). Both groups received lenalidomide until disease progression, unacceptable side effects, or both. The primary end point was progression-free survival., Results: Among 357 patients in the RVD-alone group and 365 in the transplantation group, at a median follow-up of 76.0 months, 328 events of disease progression or death occurred; the risk was 53% higher in the RVD-alone group than in the transplantation group (hazard ratio, 1.53; 95% confidence interval [CI], 1.23 to 1.91; P<0.001); median progression-free survival was 46.2 months and 67.5 months. The percentage of patients with a partial response or better was 95.0% in the RVD-alone group and 97.5% in the transplantation group (P = 0.55); 42.0% and 46.8%, respectively, had a complete response or better (P = 0.99). Treatment-related adverse events of grade 3 or higher occurred in 78.2% and 94.2%, respectively; 5-year survival was 79.2% and 80.7% (hazard ratio for death, 1.10; 95% CI, 0.73 to 1.65)., Conclusions: Among adults with multiple myeloma, RVD plus ASCT was associated with longer progression-free survival than RVD alone. No overall survival benefit was observed. (Funded by the National Heart, Lung, and Blood Institute and others; DETERMINATION ClinicalTrials.gov number, NCT01208662.)., (Copyright © 2022 Massachusetts Medical Society.)

To understand the mechanisms that mediate germline genetic leukemia predisposition, we studied the inherited ribosomopathy Shwachman-Diamond syndrome (SDS), a bone marrow failure disorder with high risk of myeloid malignancies at an early age. To define the mechanistic basis of clonal hematopoiesis in SDS, we investigate somatic mutations acquired by patients with SDS followed longitudinally. Here we report that multiple independent somatic hematopoietic clones arise early in life, most commonly harboring heterozygous mutations in EIF6 or TP53. We show that germline SBDS deficiency establishes a fitness constraint that drives selection of somatic clones via two distinct mechanisms with different clinical consequences. EIF6 inactivation mediates a compensatory pathway with limited leukemic potential by ameliorating the underlying SDS ribosome defect and enhancing clone fitness. TP53 mutations define a maladaptive pathway with enhanced leukemic potential by inactivating tumor suppressor checkpoints without correcting the ribosome defect. Subsequent development of leukemia was associated with acquisition of biallelic TP53 alterations. These results mechanistically link leukemia predisposition to germline genetic constraints on cellular fitness, and provide a rational framework for clinical surveillance strategies.

Quality of response to immunosuppressive therapy and long-term outcomes for pediatric severe aplastic anemia remain incompletely characterized. Contemporary evidence to inform treatment of relapsed or refractory severe aplastic anemia for pediatric patients is also limited. The clinical features and outcomes for 314 children treated from 2002 to 2014 with immunosuppressive therapy for acquired severe aplastic anemia were analyzed retrospectively from 25 institutions in the North American Pediatric Aplastic Anemia Consortium. The majority of subjects (n=264) received horse anti-thymocyte globulin (hATG) plus cyclosporine (CyA) with a median 61 months follow up. Following hATG/CyA, 71.2% (95%CI: 65.3,76.6) achieved an objective response. In contrast to adult studies, the quality of response achieved in pediatric patients was high, with 59.8% (95%CI: 53.7,65.8) complete response and 68.2% (95%CI: 62.2,73.8) achieving at least a very good partial response with a platelet count ≥50×10 9 L. At five years post-hATG/CyA, overall survival was 93% (95%CI: 89,96), but event-free survival without subsequent treatment was only 64% (95%CI: 57,69) without a plateau. Twelve of 171 evaluable patients (7%) acquired clonal abnormalities after diagnosis after a median 25.2 months (range: 4.3-71 months) post treatment. Myelodysplastic syndrome or leukemia developed in 6 of 314 (1.9%). For relapsed/refractory disease, treatment with a hematopoietic stem cell transplant had a superior event-free survival compared to second immunosuppressive therapy treatment in a multivariate analysis (HR=0.19, 95%CI: 0.08,0.47; P =0.0003). This study highlights the need for improved therapies to achieve sustained high-quality remission for children with severe aplastic anemia., (Copyright© 2019 Ferrata Storti Foundation.)

Patterns of myeloid growth factor (GF) usage and febrile neutropenia (FN) were examined in patients >60 years of age with diffuse large B-cell non-Hodgkin lymphoma (DLBCL) enrolled on CALGB 9793/ECOG-SWOG 4494, receiving initial therapy with cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or rituximab + CHOP (R-CHOP). Myeloid GFs were administered to 256/520 (49%) patients. Indications for use were: prevent dose reduction/dose delay (81%, 207/256); treat FN or non-febrile neutropenia (NFN) (19%, 48/256). One or more FN episodes occurred in 41% (212/520) of patients, with FN most often in cycle 1 (38% of episodes). In multivariate analysis, risk factors for FN included age >65 years (odds ratio (OR) = 2.6, 95% CI: [1.4, 4.9]) and anemia (hemoglobin <12 g/dl) (OR =2.2, 95% confidence intervals (CI): [1.4, 3.5]. Myeloid GF use was common in this older DLBCL population receiving CHOP-based therapy, as was FN, especially during cycle one. Risk factors predictive for FN should be used prospectively to identify patients for whom myeloid GFs are best utilized.

Background: High-dose chemotherapy plus autologous stem-cell transplantation has been the standard treatment for newly diagnosed multiple myeloma in adults up to 65 years of age. However, promising data on the use of combination therapy with lenalidomide, bortezomib, and dexamethasone (RVD) in this population have raised questions about the role and timing of transplantation., Methods: We randomly assigned 700 patients with multiple myeloma to receive induction therapy with three cycles of RVD and then consolidation therapy with either five additional cycles of RVD (350 patients) or high-dose melphalan plus stem-cell transplantation followed by two additional cycles of RVD (350 patients). Patients in both groups received maintenance therapy with lenalidomide for 1 year. The primary end point was progression-free survival., Results: Median progression-free survival was significantly longer in the group that underwent transplantation than in the group that received RVD alone (50 months vs. 36 months; adjusted hazard ratio for disease progression or death, 0.65; P<0.001). This benefit was observed across all patient subgroups, including those stratified according to International Staging System stage and cytogenetic risk. The percentage of patients with a complete response was higher in the transplantation group than in the RVD-alone group (59% vs. 48%, P=0.03), as was the percentage of patients in whom minimal residual disease was not detected (79% vs. 65%, P<0.001). Overall survival at 4 years did not differ significantly between the transplantation group and the RVD-alone group (81% and 82%, respectively). The rate of grade 3 or 4 neutropenia was significantly higher in the transplantation group than in the RVD-alone group (92% vs. 47%), as were the rates of grade 3 or 4 gastrointestinal disorders (28% vs. 7%) and infections (20% vs. 9%). No significant between-group differences were observed in the rates of treatment-related deaths, second primary cancers, thromboembolic events, and peripheral neuropathy., Conclusions: Among adults with multiple myeloma, RVD therapy plus transplantation was associated with significantly longer progression-free survival than RVD therapy alone, but overall survival did not differ significantly between the two approaches. (Supported by Celgene and others; IFM 2009 Study ClinicalTrials.gov number, NCT01191060 .).

Everolimus, an oral mammalian target of rapamycin (mTOR) inhibitor, has been studied in multiple myeloma (MM) but lacks significant single agent activity. Based on preclinical studies showing synergistic activity of mTOR inhibitors with lenalidomide, we studied the combination of lenalidomide and everolimus in relapsed or refractory MM in a phase I clinical trial. We assessed patient samples using gene expression, Western blotting and immunohistochemistry to probe the mTOR pathway. Twenty-six patients were evaluable for toxicity. Dose-limiting toxicities included grade 4 neutropenia and thrombocytopenia. The maximum tolerated dose was lenalidomide 15 mg and everolimus 5 mg for 21 d with a 7 d rest period. Grade 3/4 adverse events included thrombocytopenia (35%) and neutropenia (42%). The overall response rate was 65% (1 complete response + 4 partial response + 10 minimal response). The median progression-free survival was 5·5 months and median overall survival was 29·5 months. Biomarker data demonstrated downregulation of phosphorylated p70S6K. Gene expression profiling suggested activation of mTOR in responders versus non-responders. The combination of lenalidomide and everolimus was well tolerated with predictable toxicities and showed responses in a heavily pretreated population. When confirmed with larger patient numbers, this analysis may guide patient selection for future clinical trials of mTOR inhibition in MM., (© 2014 John Wiley & Sons Ltd.)

Purpose: The Programmed Death-1 (PD-1) immune checkpoint pathway may be usurped by tumors, including diffuse large B-cell lymphoma (DLBCL), to evade immune surveillance. The reconstituting immune landscape after autologous hematopoietic stem-cell transplantation (AHSCT) may be particularly favorable for breaking immune tolerance through PD-1 blockade., Patients and Methods: We conducted an international phase II study of pidilizumab, an anti-PD-1 monoclonal antibody, in patients with DLBCL undergoing AHSCT, with correlative studies of lymphocyte subsets. Patients received three doses of pidilizumab beginning 1 to 3 months after AHSCT., Results: Sixty-six eligible patients were treated. Toxicity was mild. At 16 months after the first treatment, progression-free survival (PFS) was 0.72 (90% CI, 0.60 to 0.82), meeting the primary end point. Among the 24 high-risk patients who remained positive on positron emission tomography after salvage chemotherapy, the 16-month PFS was 0.70 (90% CI, 0.51 to 0.82). Among the 35 patients with measurable disease after AHSCT, the overall response rate after pidilizumab treatment was 51%. Treatment was associated with increases in circulating lymphocyte subsets including PD-L1E-bearing lymphocytes, suggesting an on-target in vivo effect of pidilizumab., Conclusion: This is the first demonstration of clinical activity of PD-1 blockade in DLBCL. Given these results, PD-1 blockade after AHSCT using pidilizumab may represent a promising therapeutic strategy in this disease.

Objective: Bisphosphonate-related osteonecrosis of the jaws is a well-established disorder in which patients treated with bisphosphonates develop exposed necrotic bone in the oral cavity. The objective of this study was to report staging and treatment outcomes in a large cohort of patients with bisphosphonate-related osteonecrosis of the jaws managed primarily with non-surgical measures., Patients and Methods: A retrospective medical record review was conducted from 1998 to 2010 of all patients referred for the management of bisphosphonate-related osteonecrosis of the jaws. Clinical findings and staging were assessed at initial consultation and each follow-up visit. Management was provided to minimize symptoms and/or achieve resolution of lesions. Treatment responses were defined based on symptoms and/or change in staging., Results: There were 120 records reviewed and 97 patients seen for follow-up (median 12months); 90% were cancer patients. Bisphosphonate-related osteonecrosis of the jaws was managed with observation (16%), antibiotics (55%), non-surgical sequestrectomy±antibiotics (14%), or surgery±antibiotics (14%). There were 14 patients (12%) who presented with stage 0 disease; 41%, 43%, and 5% of patients presented at stages 1, 2, and 3, respectively. Greater than 70% of patients improved, remained asymptomatic, and/or showed complete re-epithelialization when evaluated at 0-3, 3-6, 6-9, 9-12, and/or >12months. Seventeen patients developed non-infectious complications of BONJ including neuropathy (N=9), painful tongue ulcers (N=7), or pathologic fracture (N=1). Twelve patients with multiple myeloma underwent hematopoietic cell transplantation without infectious complications., Conclusions: A primarily non-surgical approach appears to be a successful management strategy for bisphosphonate-related osteonecrosis of the jaws. Overall, 71-80% of patients improved or remained asymptomatic with a median follow-up of 12months., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

To assess if immunochemotherapy influenced the prognostic value of IPI in elderly diffuse large B-cell lymphoma (DLBCL) patients, we evaluated the performance of the standard International Prognostic Index (IPI) and following modifications: age adjusted (AA)-IPI, revised (R)-IPI, and an elderly IPI with age cut-off 70 years (E-IPI) in patients > 60 years treated with RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). In 267 patients, by IPI/AA-IPI 60% were high-intermediate, 53% high and 12% low risk. With R-IPI, 60% were poor risk and none very good risk. Using E-IPI, 45% were high-intermediate/high risk and 27% low risk. No differences in outcome were seen in the low/low-intermediate groups with IPI/AA-IPI. For E-IPI, failure-free survival (FFS) and overall survival (OS) were significantly different for low/low-intermediate groups. No differences were detected in the four indices with model fit/discrimination measures; however, E-IPI ranked highest. For elderly R-CHOP treated patients, distribution of IPI/AA-IPI skewed toward high/high-intermediate risk with no differences in FFS/OS between low/low-intermediate risk. In contrast, with E-IPI, more are classified as low risk with significant differences in FFS/OS for low-intermediate compared to low risk. The R-IPI does not identify a very good risk group, thus minimizing its utility in this population. The prognostic discrimination provided by the E-IPI for low and low-intermediate elderly DLBCL patients needs validation by other datasets., (© 2010 Blackwell Publishing Ltd.)

Purpose: To prospectively investigate the prognostic significance of p21 and p53 expression in diffuse large B-cell lymphoma in the context of the U.S. Intergroup trial comparing conventional cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy to rituximab-CHOP (R-CHOP) induction, with or without maintenance rituximab., Experimental Design: Immunohistochemical staining of 197 paraffin-embedded biopsy specimens was scored by an independent panel of experts., Results: The cyclin-dependent kinase inhibitor, p21, was expressed in 55% of cases examined. In a multivariable analysis adjusting for International Prognostic Index score and BCL2 status, p21 expression was a significant, independent, favorable predictive factor for failure-free survival (relative risk, 0.3; P = 0.001) and overall survival (relative risk, 0.3; P = 0.003) for patients treated with R-CHOP. Expression of p21 was not predictive of outcome for CHOP-treated patients. Only p21-positive cases benefited from the addition of rituximab to CHOP. Among p21-positive patients, treatment with R-CHOP was associated with a higher failure-free survival rate at 5 years compared with CHOP (61% versus 24%; P = 0.01). In contrast, no significant differences were detected in failure-free survival according to treatment arm for p21-negative patients. Expression of p53, alone or in combination with p21, did not predict for outcome in univariable or multivariable analyses., Conclusions: In this study, p21 protein expression emerged as an important independent predictor of a favorable clinical outcome when rituximab was added to CHOP therapy. These data suggest that rituximab-related effects on lymphoma survival pathways may be functionally linked to p21 activity.

Purpose: To address early and late treatment failures in older patients with diffuse large B-cell lymphoma (DLBCL), we designed a two-stage randomized trial of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) versus rituximab plus CHOP (R-CHOP), with a second random assignment to maintenance rituximab (MR) or observation in responding patients., Patients and Methods: Untreated DLBCL patients who were 60 years or older were randomly assigned to R-CHOP (n = 318) or CHOP (n = 314); 415 responders were randomly assigned to MR (n = 207) or observation (n = 208). The primary end point was failure-free survival (FFS). All P values were two sided., Results: Three-year FFS rate was 53% for R-CHOP patients and 46% for CHOP patients (P = .04) at a median follow-up time of 3.5 years. Two-year FFS rate from second random assignment was 76% for MR compared with 61% for observation (P = .009). No significant differences in survival were seen according to induction or maintenance therapy. FFS was prolonged with MR after CHOP (P = .0004) but not after R-CHOP (P = .81) with 2-year FFS rates from second random assignment of 77%, 79%, 74%, and 45% for R-CHOP, R-CHOP + MR, CHOP + MR, and CHOP, respectively. In a secondary analysis excluding MR patients, R-CHOP alone reduced the risks of treatment failure (P = .003) and death (P = .05) compared with CHOP alone., Conclusion: Rituximab administered as induction or maintenance with CHOP chemotherapy significantly prolonged FFS in older DLBCL patients. After R-CHOP, no benefit was provided by MR. These results, which are consistent with an additive effect of rituximab, suggest that future studies could focus on maintenance strategies with novel agents as well as new induction therapies.

Bevacizumab is a humanized monoclonal antibody directed against vascular endothelial growth factor (VEGF-A). Non-Hodgkin's lymphoma patients with high serum VEGF levels have an inferior survival compared to patients with low VEGF levels. Bevacizumab was administered through a central line at 15 mg kg(-1) IV on day 1 followed by rituximab (R) and CHOP on day 2 for cycle 1 and day 1 for cycles 2 - 8. Serum levels of bevacizumab and R were measured at specified time points to assess pharmacokinetics (PK). Plasma and urine samples were also analysed for VEGF. Tumor samples were stained for VEGF, CD31 and factor VIII by immunohistochemistry. Thirteen patients with newly-diagnosed DLBCL received a total of 88 cycles (range 2 - 8, median 7). Best response included five CR, six PR, one SD and one PD with an overall response rate of 85% and complete response rate of 38%. The 12-month PFS is 77% and a median follow-up of 16.9 months for the surviving patients. All tumor samples stained strongly positive for VEGF and there was a marginal association between baseline plasma VEGF and response (p = 0.04). Patients with higher plasma VEGF levels were generally younger and had bulky disease. Micro-vessel density did not correlate with presenting disease characteristics, VEGF expression or response. The PK of bevacizumab and rituximab were not influenced by combined treatment. In this patient population, treatment with RA-CHOP did not result in any episodes of grade 3 or 4 proteinuria, heart failure or hemorrhage. The RA-CHOP combination was generally well tolerated and safe.

Bcl-6 protein expression, a marker of germinal center origin, has been associated with a favorable prognosis in diffuse large B-cell lymphoma (DLBCL). To determine the prognostic significance of this marker when rituximab (R) was added to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy, we prospectively studied Bcl-6 protein expression by immunohistochemical staining of 199 paraffin-embedded specimens from patients enrolled in the US Intergroup phase 3 trial comparing R-CHOP to CHOP with or without maintenance R. In Bcl-6(-) patients, failure-free survival (FFS) and overall survival (OS) were prolonged for those treated with R-CHOP alone compared to CHOP alone (2-year FFS 76% versus 9%, P < .001; 2-year OS 79% versus 17%, P < .001). In contrast, no differences in FFS and OS were detected between treatment arms for Bcl-6(+) cases. In the multivariate analysis, treatment arm (CHOP versus R-CHOP) was the major determinant of both FFS (P < .001) and OS (P < .001) for the Bcl-6(-) subset, whereas the International Prognostic Index risk group was the only significant predictor of outcome among Bcl-6(+) cases. Bcl-2 protein expression was not predictive of outcome in either group. In this study, we observed a reduction in treatment failures and death with the addition of R to CHOP in Bcl-6(-) DLBCL cases only. Our finding that Bcl-6(+) cases did not benefit from the addition of R to CHOP requires independent confirmation.

Previous studies of etoposide for metastatic breast cancer commonly used bolus regimens given over a short period of time and included heavily pretreated patients. Results were poor. Chronic oral regimens would be expected to be superior to bolus doses based on pharmacologic studies and patients with less previous chemotherapy would be expected to have higher response rates. We studied the efficacy of oral etoposide at a dose of 50 mg/m2/day for 21 days of a 28-day cycle in good-risk patients with metastatic breast cancer. Healthy patients (Eastern Cooperative Oncology Group performance status 0, 1, or 2) who had not received chemotherapy for at least 1 year before study entry were selected for therapy. Thirty-four patients were entered; three patients were ineligible and one was cancelled. Thirty patients were available for analysis of response. One complete response and eight partial responses were documented (response rate, 30%; 95% confidence interval, 15-49%). A higher response rate was observed in those patients who never received chemotherapy compared with those who had received prior chemotherapy (57 vs. 6%, p = 0.004). There were two treatment-related deaths, both owing to myelosuppression and infection. We found long-term administration of oral etoposide to have a reasonable response rate for metastatic breast cancer (30%). Our response rate was comparable to those of other published studies of long-term oral etoposide regimens for metastatic breast cancer. Response rates in single-arm studies have generally been higher for long-term oral regimens than those for bolus regimens. We also found the regimen to be significantly toxic, an observation that may be underemphasized in the earlier literature.

With parametric cure models, we can express survival parameters (e.g. cured fraction, location and scale parameters) as functions of covariates. These models can measure survival from a specific disease process, either by examining deaths due to the cause under study (cause-specific survival), or by comparing all deaths to those in a matched control population (relative survival). We present a binomial maximum likelihood algorithm to be used for actuarial data, where follow-up times are grouped into specific intervals. Our algorithm provides simultaneous maximum likelihood estimates for all the parameters of a cure model and can be used for cause-specific or relative survival analysis with a variety of survival distributions. Current software does not provide the flexibility of this unified approach.

Pneumocystis carinii pneumonia (PCP) is a life-threatening but preventable infection that may occur after bone marrow transplantation (BMT). Although various prophylactic regimens have been used in this setting to prevent active infection, their efficacy, toxicity profile, and impact on outcomes are poorly described in this patient group. We undertook a retrospective cohort study in which we reviewed the records of 451 adult patients who underwent BMT for hematologic malignancies, aplastic anemia, or myelodysplasia over a 7-year period at the Brigham and Women's Hospital. Post-BMT PCP prophylaxis consisted of aerosolized pentamidine (AP) 150 mg every 2 weeks or 300 mg per month, trimethoprim/sulfamethoxazole (TMP/SMX) 160/800 mg orally b.i.d. 3 times per week, or dapsone 100 mg orally each day. Prophylaxis was continued for 1 year post-BMT in all patients when clinically feasible. One hundred twenty-one patients were unevaluable because of death or relapse <60 days after BMT (n = 89), loss to follow-up upon hospital discharge (n = 20), or other reasons (n = 12). Three eligible patients did not receive any prophylaxis and were not further evaluated. Of the 327 patients analyzed, 133 underwent autologous BMT, 4 syngeneic BMT, 159 related allogeneic BMT, and 31 unrelated allogeneic BMT. Graft-versus-host disease prophylaxis in the 190 patients receiving allogeneic BMT consisted of T-cell depletion with anti-CD5 and complement in 58 patients and cyclosporine/methotrexate or FK506 with or without steroids in 132 patients. Eight of 327 (2.4%) documented PCP cases were identified, 0 of 105 in patients receiving only TMP/SMX. Four cases occurred in patients receiving only AP (4/44, 9.1%; odds ratio [OR] relative to TMP/SMX 23.4, 95% confidence interval [CI] 1.2, 445.2); 1 in patients receiving only dapsone (1/31, 3.2%; OR not significant); 2 in patients receiving more than 1 prophylactic regimen (2/147 1.4%; OR not significant); and 1 >1 year post-BMT in a patient who was off PCP prophylaxis. Although the patients receiving only AP had a significantly lower probability of treatment-related toxicity than those receiving TMP/SMX (OR 0.19 [95% CI 0.04, 0.851), the probability of their acquiring other serious non-PCP infections was increased (OR 2.2 [95% CI 1.0, 4.6]), and the probability of their dying by 1 year post-BMT was significantly higher (OR 5.2 [95% CI 2.4, 26.6]), even when adjusted for variables such as type of BMT (autologous versus allogeneic; high versus low risk) and sex. Although AP is associated with fewer toxicities, the data show that it is inferior to TMP/SMX in preventing PCP in the post-BMT setting and is associated with an increased risk of other infections and a higher mortality at 1 year after BMT.

The hypothesis that chronic stimulation of C-fibres by inhaled irritants contributes to the inflammatory changes that occur during the development of chronic bronchitis was tested. The effect of neonatal capsaicin pretreatment on the development of respiratory tract inflammation was examined in a rat model of chronic bronchitis induced by SO2 exposure. Adult capsaicin- and vehicle-treated rats were exposed to SO2 (250 parts per million (ppm) 5 h x day(-1)) for one day, 2 weeks or 4 weeks. Nasal (NL), airway (AL) and bronchoalveolar (BAL) lavages were performed and the number and types of cells in the lavage fluids measured. SO2-induced changes in ventilation were also measured on day 1 of SO2 exposure and in the 3rd and 5th week of exposure. In the vehicle-treated rats, neutrophils became elevated in NL after just one day of SO2 exposure, in AL after 2 weeks, and in the BAL after 4 weeks. In comparison to vehicle animals, more neutrophils were recovered in the AL of capsaicin-treated rats after one day of SO2 (p=0.012), and in the BAL after 2 or 4 weeks (p=0.004 and p=0.01, respectively). On day 1, SO2 caused a transient increase in tidal volume and a sustained decrease in frequency that was not different in capsaicin- and vehicle-treated rats. With continued exposure, these ventilatory responses to SO2 were attenuated in both groups of rats. These data support the hypothesis that the presence of C-fibres limits or delays the inflammation that occurs during the development of chronic bronchitis induced by SO2 exposure. The protective effect of C-fibres is not the result of ventilatory responses to stimulation of these afferents.

Among the tests that can be used to detect dose-related trends in count data from toxicological studies are nonparametric tests such as the Jonckheere-Terpstra and likelihood-based tests, for example, based on a Poisson model. This paper was motivated by a data set of tumor counts in which conflicting conclusions were obtained using these two tests. To define situations where one test may be preferable, we compared the small and large sample performance of these two tests as well as a robust and conditional version of the likelihood-based test in the absence and presence of a dose-related trend for both Poisson and overdispersed Poisson data. Based on our results, we suggest using the Poisson test when little overdispersion is present in the data. For more overdispersed data, we recommend using the robust Poisson test for highly discrete data (response rate lower than 2-3) and the robust Poisson test or the Jonckheere-Terpstra test for moderately discrete or continuous data (average responses larger than 2 or 3). We also studied the effects of dose metameter misspecification. A clear effect on efficiency was seen when the 'wrong' dose metameter was used to compute the test statistic. In general, unless there is strong reason to do otherwise, we recommend the use of equally spaced dose levels when applying the Poisson or robust Poisson test for trend.

In order to identify nonadditive effects on development, three compounds were combined using five dosages of each agent (a 5 x 5 x 5 full-bacterial design). Trichloroethylene (TCE), di(2-ethylhexyl) phthalate (DEHP), and heptachlor (HEPT), in corn oil, were administered by gavage to Fischer-344 rats on Gestation Days 6-15. Dose levels were 0, 10.1, 32, 101, and 320 mg/kg/day for TCE; 0, 24.7, 78, 247, and 780 mg/kg/day for DEHP; and 0, 0.25, 0.8, 2.5, and 8 mg/kg/day for HEPT. The dams were allowed to deliver and their pups were weighed and examined postnatally. Maternal death showed no main effects but DEHP and HEPT were synergistic. For maternal weight gain on Gestational Days 6-8, main effects for all three agents were observed, as well as 6-8 main effects for all three agents were observed, as well as TCE-DEHP synergism, and DEHP-HEPT antagonism. Maternal weight gain on Gestational Days 6-20 adjusted for litter weight showed main effects for TCE and HEPT, but no interactions. Main effects for all three agents were evident for full-litter resorptions and prenatal loss. The HEPT main effects were unexpected and were interpreted as reflecting potentiation by HEPT of the other agents. For full-litter loss, the TCE-HEPT and DEHP-HEPT interactions were antagonistic, perhaps due to a "ceiling" effect. For prenatal loss, the TCE-DEHP interaction was synergistic. Postnatal loss showed DEHP and HEPT main effects but no interaction. Analysis of pup weights on Day 1 revealed TCE and DEHP main effects and DEHP-HEPT antagonism; on Day 6, DEHP and HEPT main effects, DEHP-HEPT antagonism, and TCE-DEHP synergism were evident. Microphthalmia and anophthalmia incidences revealed TCE and DEHP main effects but no interactions. This extensive examination of a full-factorial design elucidates the complexities of studying and interpreting mixture toxicity. The data are available for further analysis.