Interaction molecular QTL mapping discovers cellular and environmental modifiers of genetic regulatory effects

Bulk-tissue molecular quantitative trait loci (QTLs) have been the starting point for interpreting disease-associated variants, and context-specific QTLs show particular relevance for disease. Here, we present the results of mapping interaction QTLs (iQTLs) for cell type, age, and other phenotypic variables in multi-omic, longitudinal data from the blood of individuals of diverse ancestries. By modeling the interaction between genotype and estimated cell-type proportions, we demonstrate that cell-type iQTLs could be considered as proxies for cell-type-specific QTL effects, particularly for the most abundant cell type in the tissue. The interpretation of age iQTLs, however, warrants caution because the moderation effect of age on the genotype and molecular phenotype association could be mediated by changes in cell-type composition. Finally, we show that cell-type iQTLs contribute to cell-type-specific enrichment of diseases that, in combination with additional functional data, could guide future functional studies. Overall, this study highlights the use of iQTLs to gain insights into the context specificity of regulatory effects.

Large-scale causal discovery using interventional data sheds light on the regulatory network architecture of blood traits

Inference of directed biological networks is an important but notoriously challenging problem. We introduce inverse sparse regression (inspre), an approach to learning causal networks that leverages large-scale intervention-response data. Applied to 788 genes from the genome-wide perturb-seq dataset, inspre helps elucidate the network architecture of blood traits.

Multiset correlation and factor analysis enables exploration of multi-omics data

Multi-omics datasets are becoming more common, necessitating better integration methods to realize their revolutionary potential. Here, we introduce multi-set correlation and factor analysis (MCFA), an unsupervised integration method tailored to the unique challenges of high-dimensional genomics data that enables fast inference of shared and private factors. We used MCFA to integrate methylation markers, protein expression, RNA expression, and metabolite levels in 614 diverse samples from the Trans-Omics for Precision Medicine/Multi-Ethnic Study of Atherosclerosis multi-omics pilot. Samples cluster strongly by ancestry in the shared space, even in the absence of genetic information, while private spaces frequently capture dataset-specific technical variation. Finally, we integrated genetic data by conducting a genome-wide association study (GWAS) of our inferred factors, observing that several factors are enriched for GWAS hits and trans-expression quantitative trait loci. Two of these factors appear to be related to metabolic disease. Our study provides a foundation and framework for further integrative analysis of ever larger multi-modal genomic datasets.

Interaction molecular QTL mapping discovers cellular and environmental modifiers of genetic regulatory effects

Bulk tissue molecular quantitative trait loci (QTLs) have been the starting point for interpreting disease-associated variants, while context-specific QTLs show particular relevance for disease. Here, we present the results of mapping interaction QTLs (iQTLs) for cell type, age, and other phenotypic variables in multi-omic, longitudinal data from blood of individuals of diverse ancestries. By modeling the interaction between genotype and estimated cell type proportions, we demonstrate that cell type iQTLs could be considered as proxies for cell type-specific QTL effects. The interpretation of age iQTLs, however, warrants caution as the moderation effect of age on the genotype and molecular phenotype association may be mediated by changes in cell type composition. Finally, we show that cell type iQTLs contribute to cell type-specific enrichment of diseases that, in combination with additional functional data, may guide future functional studies. Overall, this study highlights iQTLs to gain insights into the context-specificity of regulatory effects.

MiniBooNE and MicroBooNE Combined Fit to a 3+1 Sterile Neutrino Scenario

This Letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE electron-(anti)neutrino and muon-(anti)neutrino data alone and in combination with MicroBooNE electron-neutrino data. The best-fit parameters of the combined fit with the exclusive charged-current quasielastic analysis (inclusive analysis) are Δm^{2}=0.209  eV^{2}(0.033  eV^{2}), |U_{e4}|^{2}=0.016(0.500), |U_{μ4}|^{2}=0.500(0.500), and sin^{2}(2θ_{μe})=0.0316(1.0). Comparing the no-oscillation scenario to the 3+1 model, the data prefer the 3+1 model with a Δχ^{2}/d.o.f.=24.7/3(17.3/3), a 4.3σ(3.4σ) preference assuming the asymptotic approximation given by Wilks's theorem.

Welch-weighted Egger regression reduces false positives due to correlated pleiotropy in Mendelian randomization

Modern population-scale biobanks contain simultaneous measurements of many phenotypes, providing unprecedented opportunity to study the relationship between biomarkers and disease. However, inferring causal effects from observational data is notoriously challenging. Mendelian randomization (MR) has recently received increased attention as a class of methods for estimating causal effects using genetic associations. However, standard methods result in pervasive false positives when two traits share a heritable, unobserved common cause. This is the problem of correlated pleiotropy. Here, we introduce a flexible framework for simulating traits with a common genetic confounder that generalizes recently proposed models, as well as a simple approach we call Welch-weighted Egger regression (WWER) for estimating causal effects. We show in comprehensive simulations that our method substantially reduces false positives due to correlated pleiotropy while being fast enough to apply to hundreds of phenotypes. We apply our method first to a subset of the UK Biobank consisting of blood traits and inflammatory disease, and then to a broader set of 411 heritable phenotypes. We detect many effects with strong literature support, as well as numerous behavioral effects that appear to stem from physician advice given to people at high risk for disease. We conclude that WWER is a powerful tool for exploratory data analysis in ever-growing databases of genotypes and phenotypes.

Estimating cross-population genetic correlations of causal effect sizes

Recent studies have examined the genetic correlations of single-nucleotide polymorphism (SNP) effect sizes across pairs of populations to better understand the genetic architectures of complex traits. These studies have estimated ρ g , the cross-population correlation of joint-fit effect sizes at genotyped SNPs. However, the value of ρ g depends both on the cross-population correlation of true causal effect sizes ( ρ b ) and on the similarity in linkage disequilibrium (LD) patterns in the two populations, which drive tagging effects. Here, we derive the value of the ratio ρ g / ρ b as a function of LD in each population. By applying existing methods to obtain estimates of ρ g , we can use this ratio to estimate ρ b . Our estimates of ρ b were equal to 0.55 ( SE = 0.14) between Europeans and East Asians averaged across nine traits in the Genetic Epidemiology Research on Adult Health and Aging data set, 0.54 ( SE = 0.18) between Europeans and South Asians averaged across 13 traits in the UK Biobank data set, and 0.48 ( SE = 0.06) and 0.65 ( SE = 0.09) between Europeans and East Asians in summary statistic data sets for type 2 diabetes and rheumatoid arthritis, respectively. These results implicate substantially different causal genetic architectures across continental populations.

Expression reflects population structure

Population structure in genotype data has been extensively studied, and is revealed by looking at the principal components of the genotype matrix. However, no similar analysis of population structure in gene expression data has been conducted, in part because a naïve principal components analysis of the gene expression matrix does not cluster by population. We identify a linear projection that reveals population structure in gene expression data. Our approach relies on the coupling of the principal components of genotype to the principal components of gene expression via canonical correlation analysis. Our method is able to determine the significance of the variance in the canonical correlation projection explained by each gene. We identify 3,571 significant genes, only 837 of which had been previously reported to have an associated eQTL in the GEUVADIS results. We show that our projections are not primarily driven by differences in allele frequency at known cis-eQTLs and that similar projections can be recovered using only several hundred randomly selected genes and SNPs. Finally, we present preliminary work on the consequences for eQTL analysis. We observe that using our projection co-ordinates as covariates results in the discovery of slightly fewer genes with eQTLs, but that these genes replicate in GTEx matched tissue at a slightly higher rate.

Significant Excess of Electronlike Events in the MiniBooNE Short-Baseline Neutrino Experiment

The MiniBooNE experiment at Fermilab reports results from an analysis of ν_{e} appearance data from 12.84×10^{20} protons on target in neutrino mode, an increase of approximately a factor of 2 over previously reported results. A ν_{e} charged-current quasielastic event excess of 381.2±85.2 events (4.5σ) is observed in the energy range 200<E_{ν}^{QE}<1250  MeV. Combining these data with the ν[over ¯]_{e} appearance data from 11.27×10^{20} protons on target in antineutrino mode, a total ν_{e} plus ν[over ¯]_{e} charged-current quasielastic event excess of 460.5±99.0 events (4.7σ) is observed. If interpreted in a two-neutrino oscillation model, ν_{μ}→ν_{e}, the best oscillation fit to the excess has a probability of 21.1%, while the background-only fit has a χ^{2} probability of 6×10^{-7} relative to the best fit. The MiniBooNE data are consistent in energy and magnitude with the excess of events reported by the Liquid Scintillator Neutrino Detector (LSND), and the significance of the combined LSND and MiniBooNE excesses is 6.0σ. A two-neutrino oscillation interpretation of the data would require at least four neutrino types and indicate physics beyond the three neutrino paradigm. Although the data are fit with a two-neutrino oscillation model, other models may provide better fits to the data.

First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions

We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest (K^{+}→μ^{+}ν_{μ}) at the NuMI beamline absorber. These signal ν_{μ}-carbon events are distinguished from primarily pion decay in flight ν_{μ} and ν[over ¯]_{μ} backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9σ level. The muon kinetic energy, neutrino-nucleus energy transfer (ω=E_{ν}-E_{μ}), and total cross section for these events are extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of ω using neutrinos, a quantity thus far only accessible through electron scattering.

Improved search for ν¯(μ)→ν¯(e) oscillations in the MiniBooNE experiment

The MiniBooNE experiment at Fermilab reports results from an analysis of ν[over ¯](e) appearance data from 11.27×10(20) protons on target in the antineutrino mode, an increase of approximately a factor of 2 over the previously reported results. An event excess of 78.4±28.5 events (2.8σ) is observed in the energy range 200<E(ν)(QE)<1250 MeV. If interpreted in a two-neutrino oscillation model, ν[over ¯](μ)→ν[over ¯](e), the best oscillation fit to the excess has a probability of 66% while the background-only fit has a χ(2) probability of 0.5% relative to the best fit. The data are consistent with antineutrino oscillations in the 0.01<Δm(2)<1.0 eV(2) range and have some overlap with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector. All of the major backgrounds are constrained by in situ event measurements so nonoscillation explanations would need to invoke new anomalous background processes. The neutrino mode running also shows an excess at low energy of 162.0±47.8 events (3.4σ) but the energy distribution of the excess is marginally compatible with a simple two neutrino oscillation formalism. Expanded models with several sterile neutrinos can reduce the incompatibility by allowing for CP violating effects between neutrino and antineutrino oscillations.

Event excess in the MiniBooNE search for ¯νμ→¯νe oscillations

The MiniBooNE experiment at Fermilab reports results from a search for ¯ν_{μ}→¯ν_{e} oscillations, using a data sample corresponding to 5.66×10²⁰ protons on target. An excess of 20.9±14.0 events is observed in the energy range 475<E_{ν}^{QE}<1250  MeV, which, when constrained by the observed ¯ν_{μ} events, has a probability for consistency with the background-only hypothesis of 0.5%. On the other hand, fitting for ¯ν_{μ}→¯ν_{e} oscillations, the best-fit point has a χ² probability of 8.7%. The data are consistent with ¯ν_{μ}→¯ν_{e} oscillations in the 0.1 to 1.0  eV² Δm² range and with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.

What's new in psoriasis? Analysis of the clinical significance of new guidelines and systematic reviews on psoriasis published in 2008 and 2009

This review summarizes the clinical importance of 18 systematic reviews and guidelines on psoriasis published or indexed between November 2008 and October 2009. The topics covered include guidance on the use of topical, systemic and biological therapies for the treatment of psoriasis; comorbidities associated with psoriasis; and complementary therapies for psoriasis. A similar and more detailed review to this appeared in the 2009 Annual Evidence Update on Psoriasis from NHS Evidence - Skin Disorders in November 2009.

Search for electron antineutrino appearance at the deltam(2) approximately 1 eV(2) Scale

The MiniBooNE Collaboration reports initial results from a search for nu(mu)-->nu(e) oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39x10(20) protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200<E(nu)(QE)<3000 MeV: 144 electronlike events have been observed in this energy range, compared to an expectation of 139.2+/-17.6 events. No significant excess of events has been observed, both at low energy, 200-475 MeV, and at high energy, 475-1250 MeV. The data are inconclusive with respect to antineutrino oscillations suggested by data from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.

Measurement of the ratio of the numu charged-current single-pion production to quasielastic scattering with a 0.8 GeV neutrino beam on mineral oil

Using high statistics samples of charged-current numu interactions, the MiniBooNE [corrected] Collaboration reports a measurement of the single-charged-pion production to quasielastic cross section ratio on mineral oil (CH2), both with and without corrections for hadron reinteractions in the target nucleus. The result is provided as a function of neutrino energy in the range 0.4 GeV<Enu<2.4 GeV with 11% precision in the region of highest statistics. The results are consistent with previous measurements and the prediction from historical neutrino calculations.

Search for muon neutrino and antineutrino disappearance in MiniBooNE

The MiniBooNE Collaboration reports a search for nu_{micro} and nu[over]_{micro} disappearance in the Deltam;{2} region of 0.5-40 eV;{2}. These measurements are important for constraining models with extra types of neutrinos, extra dimensions, and CPT violation. Fits to the shape of the nu_{micro} and nu[over]_{micro} energy spectra reveal no evidence for disappearance at the 90% confidence level (C.L.) in either mode. The test of nu[over]_{micro} disappearance probes a region below Deltam;{2} = 40 eV;{2} never explored before.

Measurement of numicro and nue events in an off-axis horn-focused neutrino beam

We report the first observation of off-axis neutrino interactions in the MiniBooNE detector from the NuMI beam line at Fermilab. The MiniBooNE detector is located 745 m from the NuMI production target, at 110 mrad angle (6.3 degrees) with respect to the NuMI beam axis. Samples of charged-current quasielastic numicro and nue interactions are analyzed and found to be in agreement with expectation. This provides a direct verification of the expected pion and kaon contributions to the neutrino flux and validates the modeling of the NuMI off-axis beam.

Unexplained excess of electronlike events from a 1-GeV neutrino beam

The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46x10;{20} protons on target, 544 electronlike events are observed in this energy range, compared to an expectation of 415.2+/-43.4 events, corresponding to an excess of 128.8+/-20.4+/-38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either nu_{e} and nu[over ]_{e} charged-current scattering or nu_{mu} neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are observed compared to an expectation of 385.9+/-35.7 events.

The hidden cost of skin scars: quality of life after skin scarring

BACKGROUND

Surprisingly little is known about how skin scars affect patients' lives, though specialist clinical impressions suggest their impact is related to both their physical and psychosocial effects. Facial scars have been shown to cause high levels of anxiety and self-consciousness, but further work has been neglected. We aimed to explore the influence of skin scars on patients' quality of life (QoL) and identify potential implications for clinical practice.

METHODS

We adopted a needs-based approach to QoL and conducted semi-structured interviews with scar patients at a specialist clinic. Transcribed data underwent interpretative phenomenological analysis to identify common themes in individuals' personal experiences.

RESULTS

Thirty-four scar patients (24 women; aged 14-70 years, mean=35.7 years, SD=17.9 years) with a wide range of scar type, severity and onset were recruited. Five hundred and seventy-three statements were identified from interview transcripts relating to need impairment by skin scars. These were subsequently classified into 44 themes covering five main areas: physical comfort and functioning; acceptability to self and others; social functioning; confidence in the nature and management of the condition; emotional well-being. The majority of respondents were unhappy with their scar's appearance due to their perceived stigma and psychological associations, and thus adopted different coping behaviours to hide or compensate for them. Often this made them unsociable and interfered with their communication skills, personal relationships, work life and leisure activities. Concerns about the diagnosis and persistent nature of scars were common, whilst unempathic management by general physicians and frustrations of current treatment compounded distress.

CONCLUSIONS

There are five main areas of impact on the needs of scar patients that should be addressed in their management, which are greater and more complex than previously considered. Support services should be made available, along with clinician and public education to improve management and help reduce patient distress. A need for a carefully designed measure of scar-related QoL is also indicated, for use in clinical settings and trials.

Measurement of muon neutrino quasielastic scattering on carbon

The observation of neutrino oscillations is clear evidence for physics beyond the standard model. To make precise measurements of this phenomenon, neutrino oscillation experiments, including MiniBooNE, require an accurate description of neutrino charged current quasielastic (CCQE) cross sections to predict signal samples. Using a high-statistics sample of nu_(mu) CCQE events, MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments, accurately characterizes the CCQE events observed in a carbon-based detector. The extracted parameters include an effective axial mass, M_(A)(eff)=1.23+/-0.20 GeV, that describes the four-momentum dependence of the axial-vector form factor of the nucleon, and a Pauli-suppression parameter, kappa=1.019+/-0.011. Such a modified Fermi gas model may also be used by future accelerator-based experiments measuring neutrino oscillations on nuclear targets.

Search for electron neutrino appearance at the Delta m2 approximately 1 eV2 scale

The MiniBooNE Collaboration reports first results of a search for nu e appearance in a nu mu beam. With two largely independent analyses, we observe no significant excess of events above the background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two-neutrino appearance-only oscillation model.

Smooth muscle tumors of the rectum and anus: a collective review of the world literature

In this collective review, we have compiled all the reported cases of smooth muscle tumors of the rectum/anus in the world literature from 1959 to 1989. Our goal was to increase the data pool of smooth muscle tumors by adding these new data to that previously collected from 1881 to 1959. We increased the pool for leiomyomas from 89 to 148 and that for leiomyosarcomas from 54 to 215. By doing this, we hoped to make more accurate conclusions about smooth muscle tumors based on this increased data pool. Some interesting findings included three cases in small children that were found in our recent review: a 2-year-old with a leiomyoma and two small infants, aged 12 days and 36 days, with leiomyosarcomas. Again, the findings were probably consistent with an increased data pool. We were also able to find several more cases involving the anal region. We found the highest incidence of leiomyomas to have increased by a decade from the 40-49 year age group to the 50-59 year age group, while among leiomyosarcomas, there was about equal incidence among the 50-59 and 60-69 age groups. We doubt that these represent actual changes in the demographics, but rather that these latter findings are more accurate based on the greater quantity of cases available to us. As a further example, we found no appreciable sex difference; however, we did find more cases reported in females. From our increased data pool, we were able to find 16 more cases that were described as dumbbell-shaped, compared to one that was reported before 1959. Palpable mass, hemorrhage, and pain/discomfort continued as the most common symptoms reported at presentation. With regard to size, the majority of leiomyomas were found to be less than 5 cm in diameter, closely followed by those 5-9 cm. The majority of leiomyosarcomas were 5-9 centimeters at discovery. Most cases of leiomyoma were treated by excision, while most cases of leiomyosarcoma were treated by abdominoperineal resection, a finding consistent with old data. We hope that this paper thoroughly reviews pertinent information about leiomyomas and leiomyosarcomas of the rectum/anus and, in doing so, serves to refresh a few memories, stimulate others, and teach a few.

Smooth muscle tumors of the appendix and colon: a collective review of the world literature

In this collective review, we compiled all reported cases of smooth muscle tumors of the colon/appendix in the world literature from 1959 to 1989. Our goal was to make more accurate conclusions about these tumors based on our increased data pool.

Cardiac angiosarcoma: a case report

Primary neoplasms of the heart are rare and difficult to diagnose prior to surgery, even with modern imaging techniques. Often, the tumors are diagnosed only at autopsy. Angiosarcoma is the most common malignant neoplasm. This disease is most commonly found in middle-aged men, and the tumor is most often located in the right atrium. It commonly causes blood flow abnormalities, extensively infiltrates cardiac structures, and may extend through the heart wall to involve adjacent structures. Metastatic spread at the time of diagnosis is common, and surgical mortality is high. We present a case of primary angiosarcoma involving the right ventricle of the heart. This tumor developed 6 months after the patient had undergone coronary artery bypass surgery. The patient was initially thought to have a massive thrombus within the right ventricle but at surgery was found to have a malignant neoplasm invading the myocardium. Subsequently, he was found to have pulmonary metastases. A debulking procedure was performed, and the patient was started on chemotherapy. Rather prompt improvement occurred after the debulking procedure, but subsequent studies have indicated progression of the pulmonary metastases despite ongoing chemotherapy.

Malignant fibrous histiocytoma of the pancreas

Malignant fibrous histiocytoma (MFH) is a well-recognized soft-tissue sarcoma; however, its presentation as a primary neoplasm of the pancreas is unusual. We report a rare case of primary MFH of the pancreas treated with wide local excision and postoperative chemotherapy. Three cases of MFH of the pancreas have previously been reported in the world literature. The natural history of MFH of the pancreas cannot be summarized due to the rarity of the tumor. It appears, however, that the behavior of this tumor parallels the behavior of retroperitoneal MFH in terms of aggressiveness and poor prognosis.

Apudomas

Apudomas are neoplasms known to produce many biologically active amines. Some of these tumors have been known for 70 years, but over the last 15 years a wealth of new knowledge has been obtained. This study reports experience with apudomas over an 8-year period (1975-1983) at The Piedmont Hospital. There were 159 tumors with the potential for producing various ectopic hormones as well as biologically active amines, including 112 oat cell carcinomas, 37 carcinoid tumors, 4 paragangliomas, 2 pancreatic islet cell tumors, 2 medullary thyroid carcinomas, 1 pituitary adenoma, and 1 pinealocytoma. Of the 112 oat cell carcinomas, only 2 per cent had hormone-related symptoms. Of the carcinoid tumors, 12 were found in the appendix, 9 in the small intestine, 9 in the lungs, 4 in the colon and 2 in the rectum. Nineteen of the 37 carcinoids had hormone-related symptoms but none had a classic carcinoid syndrome. A third group of apudomas included several of relative rarity, the paragangliomas, the medullary thyroid carcinomas, the pancreatic islet cell tumors, pituitary adenomas, and pinealocytomas. Of this latter group, only the pancreatic islet cell tumors had symptomatology that could be related to ectopic hormone production.

Diffuse histiocytic lymphomas of the gastrointestinal tract in the adult

Diffuse histiocytic lymphomas (Rappaport) are extranodal lesions frequently formed in the digestive tract. They are clinically different from lymphomas of nodal origin and are no longer considered to arise from histiocytes. They comprise from one-third to one-half of non Hodgkin's lymphomas and chiefly involve the stomach and duodenum. Identification of these tumors and their place in current systems of classification, at present, depends on sophisticated immunologic, histochemical and ultramicroscopic procedures not always suitable for clinical prognosis. Staging laparotomy, useful in Hodgkin's disease, does not always correlate with the prognosis of non Hodgkin's lesions. Radical removal of the affected organ may be curative. Nonresectable lesions may be treated with radiation and chemotherapy. Methotrexate, cyclophosphamide, vincristine, prednisone, nitrogen mustard, Adriamycin, bleomycin and other substances have been used in various combinations to obtain remission of the disease. While results have been favorable, the ideal therapeutic agent has not been found.

Bladder complications in patients receiving cyclophosphamide for systemic lupus erythematosus or rheumatoid arthritis

The bladder complications of 54 patients treated with oral cyclophosphamide for systemic lupus erythematosus (43) or rheumatoid arthritis (11) were reviewed. During an observation period of 241 patient years, we saw seven cases of acute hemorrhagic cystitis and two cases of transitional cell carcinoma of the bladder. Bladder carcinoma was identified 28 and 60 months after withdrawal of the drug and resulted in the death of one patient. The late-occurring serious toxicities of cyclophosphamide should limit the use of the drug in the treatment of nonmalignant inflammatory rheumatic conditions.