Early transfusion patterns improve the Molecular International Prognostic Scoring System (IPSS-M) prediction in myelodysplastic syndromes.

BACKGROUND: The Molecular International Prognostic Scoring System (IPSS-M) is the new gold standard for diagnostic outcome prediction in patients with myelodysplastic syndromes (MDS). This study was designed to assess the additive prognostic impact of dynamic transfusion parameters during early follow-up. METHODS: We retrieved complete transfusion data from 677 adult Swedish MDS patients included in the IPSS-M cohort. Time-dependent erythrocyte transfusion dependency (E-TD) was added to IPSS-M features and analyzed regarding overall survival and leukemic transformation (acute myeloid leukemia). A multistate Markov model was applied to assess the prognostic value of early changes in transfusion patterns. RESULTS: Specific clinical and genetic features were predicted for diagnostic and time-dependent transfusion patterns. Importantly, transfusion state both at diagnosis and within the first year strongly predicts outcomes in both lower (LR) and higher-risk (HR) MDSs. In multivariable analysis, 8-month landmark E-TD predicted shorter survival independently of IPSS-M (p < 0.001). A predictive model based on IPSS-M and 8-month landmark E-TD performed significantly better than a model including only IPSS-M. Similar trends were observed in an independent validation cohort (n = 218). Early transfusion patterns impacted both future transfusion requirements and outcomes in a multistate Markov model. CONCLUSION: The transfusion requirement is a robust and available clinical parameter incorporating the effects of first-line management. In MDS, it provides dynamic risk information independently of diagnostic IPSS-M and, in particular, clinical guidance to LR MDS patients eligible for potentially curative therapeutic intervention.

Patient-Specific Measurable Residual Disease Markers Predict Outcome in Patients With Myelodysplastic Syndrome and Related Diseases After Hematopoietic Stem-Cell Transplantation.

PURPOSE: Clinical relapse is the major threat for patients with myelodysplastic syndrome (MDS) undergoing hematopoietic stem-cell transplantation (HSCT). Early detection of measurable residual disease (MRD) would enable preemptive treatment and potentially reduced relapse risk. METHODS: Patients with MDS planned for HSCT were enrolled in a prospective, observational study evaluating the association between MRD and clinical outcome. We collected bone marrow (BM) and peripheral blood samples until relapse, death, or end of study 24 months after HSCT. Patient-specific mutations were identified with targeted next-generation sequencing (NGS) panel and traced using droplet digital polymerase chain reaction (ddPCR). RESULTS: Of 266 included patients, estimated relapse-free survival (RFS) and overall survival (OS) rates 3 years after HSCT were 59% and 64%, respectively. MRD results were available for 221 patients. Relapse was preceded by positive BM MRD in 42/44 relapses with complete MRD data, by a median of 71 (23-283) days. Of 137 patients in continuous complete remission, 93 were consistently MRD-negative, 39 reverted from MRD+ to MRD-, and five were MRD+ at last sampling. Estimated 1 year-RFS after first positive MRD was 49%, 39%, and 30%, using cutoff levels of 0.1%, 0.3%, and 0.5%, respectively. In a multivariate Cox model, MRD (hazard ratio [HR], 7.99), WHO subgroup AML (HR, 4.87), TP53 multi-hit (HR, 2.38), NRAS (HR, 3.55), and acute GVHD grade III-IV (HR, 4.13) were associated with shorter RFS. MRD+ was also independently associated with shorter OS (HR, 2.65). In a subgroup analysis of 100 MRD+ patients, presence of chronic GVHD was associated with longer RFS (HR, 0.32). CONCLUSION: Assessment of individualized MRD using NGS + ddPCR is feasible and can be used for early detection of relapse. Positive MRD is associated with shorter RFS and OS (ClinicalTrials.gov identifier: NCT02872662).

MDS-Comorbidity Index using register data has prognostic impact in Swedish MDS patients.

Comorbidities influence the mortality in patients with myelodysplastic syndromes, and a growing body of evidence suggest that comorbidity history should be used in addition to established prognostic indices. A comorbidity index specific for MDS, the MDS-CI, was introduced a decade ago. In this study we aim to construct an MDS-CI version based on diagnoses from register data only, to expand its use beyond the clinical setting to retrospective and register based studies. We further test this version on a Swedish population-based MDS cohort of 2947 patients, and compare its prognostic accuracy to that of Charlson Comorbidity Index. Our register based MDS-CI divided patients into three risk groups of similar proportions as have been published for the original MDS-CI. Compared to low risk patients, intermediate and high risk patients had 50 % and 70 % higher mortality, respectively. The prognostic value of MDS-CI was equal to that of Charlson comorbidity index. Adding MDS-CI to the established prognostic factors IPSS-R and age increased the prognostic accuracy. In summary, we demonstrate that MDS-CI can be adequately estimated from diagnoses recorded in registers only, and that it is a useful tool in any future study on myelodysplastic syndromes with a need to adjust for comorbidities.

Therapy-related MDS dissected based on primary disease and treatment-a nationwide perspective.

In this population-based study, we aimed to characterize and compare subgroups of therapy-related Myelodysplastic syndromes (t-MDS) and define the implications of type of previous treatment and primary disease. We combined data from MDS patients, diagnosed between 2009 and 2017 (n = 2705), in the nationwide Swedish MDS register, with several health registers. Furthermore, using matched population controls, we investigated the prevalence of antecedent malignancies in MDS patients in comparison with the general population. This first ever nationwide study on t-MDS confirms a shorter median survival for t-MDS compared to de novo MDS (15.8 months vs 31.1 months, p < 0.001). T-MDS patients previously treated with radiation only had disease characteristics with a striking resemblance to de novo-MDS, in sharp contrast to patients treated with chemotherapy who had a significantly higher risk profile. IPSS-R and the WHO classification differentiated t-MDS into different risk groups. As compared with controls, MDS patients had a six-fold increased prevalence of a previous hematological malignancy but only a 34% increased prevalence of a previous solid tumor. T-MDS patients with a previous hematological malignancy had a dismal prognosis, due both to mortality related to their primary disease and to high-risk MDS.

Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Myelomonocytic Leukemia: Clinical and Molecular Genetic Prognostic Factors in a Nordic Population.

Chronic myelomonocytic leukemia (CMML) is an aggressive disease in which survival after allogeneic hematopoietic stem cell transplantation (HCT) remains relatively poor. An assessment of prognostic factors is an important part of treatment decision making and has the potential to be greatly improved by the inclusion of molecular genetics. However, there is a significant knowledge gap in the interpretation of mutational patterns. This study aimed to describe outcomes of allogeneic HCT in patients with CMML in relation to clinical and molecular genetic risk factors. This retrospective study included 64 patients with CMML who underwent allogeneic HCT between 2008 and 2018, with a median follow-up of 5.4 years. Next-generation sequencing using targeted myeloid panels was carried out on saved material from 51 patients from the time of transplantation. Kaplan-Meier and Cox regression were used for analysis of overall survival (OS), and cumulative incidence with competing risks and Fine and Gray models were used for analysis of relapse and nonrelapse mortality (NRM). Mutations were detected in 48 patients (94%), indicating high levels of minimal residual disease (MRD) positivity at transplantation, even among those in complete remission (CR) (n = 14), 86% of whom had detectable mutations. The most frequently mutated genes were ASXL1 (37%), TET2 (37%), RUNX1 (33%), SRSF2 (26%), and NRAS (20%). Risk stratification using the CMML-specific Prognostic Scoring System molecular score (CPSS-Mol) resulted in 45% of patients moving to a higher risk-group compared with risk stratification using the CPSS. High leucocyte count (≥13 × 109/L), transfusion requirement, and previous intensive chemotherapy were associated with higher incidence of relapse. Being in CR was not linked to better outcomes. Neither ASXL1 nor RUNX1 mutation was associated with a difference in OS, relapse, or NRM, despite being high risk in the nontransplantation setting. TET2 mutations were associated with a significantly higher 3-year OS (73% versus 40%; P = .039). Achieving MRD-negative CR was rare in this CMML cohort, which may explain why we did not observe better outcomes for those in CR. This merits further investigation. Our analyses suggest that the negative impact of ASXL1 and RUNX1 mutations can be overcome by allogeneic HCT; however, risk stratification is complex in CMML and requires larger cohorts and multivariate models, presenting an ongoing challenge in this rare disease.

Income, education and their impact on treatments and survival in patients with myelodysplastic syndromes.

OBJECTIVES: To assess whether socioeconomic indices such as income and educational level can explain part of the variation in survival among patients with myelodysplastic syndromes, and further to assess whether these factors influence care and treatment decisions. METHODS: Population-based cohort study on 2945 Swedish patients diagnosed between 2009 and 2018 and included in the Swedish MDS Register. Relative mortality was assessed by Cox regression, whereas treatment differences were assessed by Poisson regression. Regarding mortality, patients were also compared to a matched comparison group from the general population. RESULTS: Mortality was 50% higher among patients in the lowest income category compared to the highest and 40% higher in patients with mandatory school education only compared to those with college or university education. Treatment with hypomethylating agents and allogeneic stem cell transplantation, as well as investigation with cytogenetic diagnostics were also linked to income and education. The findings were not explained by differences in risk class or comorbidity at the time of diagnosis. CONCLUSIONS: Income and education are linked to survival among patients with myelodysplastic syndromes. Socioeconomic status also seems to influence treatment intensity as patients with less income and education to a lesser degree receive hypomethylating agents and transplants.

Prognostic scoring systems and comorbidities in chronic myelomonocytic leukaemia: a nationwide population-based study.

Outcomes in chronic myelomonocytic leukaemia (CMML) are highly variable and may be affected by comorbidity. Therefore, prognostic models and comorbidity indices are important tools to estimate survival and to guide clinicians in individualising treatment. In this nationwide population-based study, we assess comorbidities and for the first time validate comorbidity indices in CMML. We also compare the prognostic power of: the revised International Prognostic Scoring System (IPSS-R), CMML-specific prognostic scoring system (CPSS), MD Anderson Prognostic Scoring System (MDAPS) and Mayo score. In this cohort of 337 patients with CMML, diagnosed between 2009 and 2015, the median overall survival was 21·3 months. Autoimmune conditions were present in 25% of the patients, with polymyalgia rheumatica and Hashimoto's thyroiditis being most common. Of the tested comorbidity indices: the Charlson Comorbidity Index (CCI), Haematopoietic cell transplantation-specific Comorbidity Index (HCT-CI) and Myelodysplastic Syndrome-Specific Comorbidity Index (MDS-CI), CCI had the highest C-index (0·62) and was the only comorbidity index independently associated with survival in multivariable analyses. When comparing the prognostic power of the scoring systems, the CPSS had the highest C-index (0·69). In conclusion, using 'real-world' data we found that the CCI and CPSS have the best prognostic power and that autoimmune conditions are overrepresented in CMML.

Inflammatory functional iron deficiency common in myelofibrosis, contributes to anaemia and impairs quality of life. From the Nordic MPN study Group.

OBJECTIVES: The study investigates the hypothesis that inflammation in myelofibrosis (MF) like in myeloma and lymphoma, may disturb iron distribution and contribute to anaemia. METHODS: A cross-sectional study of 80 MF and 23 ET patients was performed. RESULTS: About 35% of anaemic MF patients had functional iron deficiency (FID) with transferrin saturation <20 and normal or elevated S-ferritin (<500 µg/L). In ET, FID was rare. In MF patients with FID, 70.6% were anaemic, vs 29.4% in patients without FID (P = 0.03). Hepcidin was significantly higher in MF patients with anaemia, including transfusion-dependent patients, 50.6 vs 24.4 µg/L (P = 0.01). There was a significant negative correlation between Hb and inflammatory markers in all MF patients: IL-2, IL-6 and TNF-α, (P < 0.01-0.03), LD (P = 0.004) and hepcidin (P = 0.03). These correlations were also seen in the subgroup of anaemic MF patients (Table ). Tsat correlated negatively with CRP (P < 0.001). Symptom burden was heavier in MF patients with FID, and MPN-SAF quality of life scores correlated with IL-6 and CRP. CONCLUSIONS: The inflammatory state of MF disturbs iron turnover, FID is common and contributes to anaemia development and impairment of QoL. Anaemic MF patients should be screened for FID.

Prognostic scoring systems for myelodysplastic syndromes (MDS) in a population-based setting: a report from the Swedish MDS register.

The myelodysplastic syndromes (MDS) have highly variable outcomes and prognostic scoring systems are important tools for risk assessment and to guide therapeutic decisions. However, few population-based studies have compared the value of the different scoring systems. With data from the nationwide Swedish population-based MDS register we validated the International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R) and the World Health Organization (WHO) Classification-based Prognostic Scoring System (WPSS). We also present population-based data on incidence, clinical characteristics including detailed cytogenetics and outcome from the register. The study encompassed 1329 patients reported to the register between 2009 and 2013, 14% of these had therapy-related MDS (t-MDS). Based on the MDS register, the yearly crude incidence of MDS in Sweden was 2·9 per 100 000 inhabitants. IPSS-R had a significantly better prognostic power than IPSS (P < 0·001). There was a trend for better prognostic power of IPSS-R compared to WPSS (P = 0·05) and for WPSS compared to IPSS (P = 0·07). IPSS-R was superior to both IPSS and WPSS for patients aged ≤70 years. Patients with t-MDS had a worse outcome compared to de novo MDS (d-MDS), however, the validity of the prognostic scoring systems was comparable for d-MDS and t-MDS. In conclusion, population-based studies are important to validate prognostic scores in a 'real-world' setting. In our nationwide cohort, the IPSS-R showed the best predictive power.

Circulating YKL-40 in patients with essential thrombocythemia and polycythemia vera treated with the novel histone deacetylase inhibitor vorinostat.

YKL-40 regulates vascular endothelial growth factors and induces tumor proliferation. We investigated YKL-40 before and after treatment with vorinostat in 31 polycythemia vera (PV) and 16 essential thrombocythemia (ET) patients. Baseline PV patient levels were 2 times higher than in healthy controls (P<0.0001) and 1.7 times higher than in ET (P=0.02). A significant correlation between YKL-40 at baseline and neutrophils, CRP, LDH, JAK2V617F and platelets in PV patients was observed, as well as a significantly greater reduction of YKL-40 levels in PV patients responding to therapy. YKL-40 might be a novel marker of disease burden and progression in myeloproliferative neoplasms.

A phase II study of vorinostat (MK-0683) in patients with polycythaemia vera and essential thrombocythaemia.

Inhibition of histone deacetylases may be an important target in patients with myeloproliferative neoplasms. This investigator-initiated, non-randomized, open-label phase II multi-centre study included 63 patients (19 essential thrombocythaemia, 44 polycythaemia vera) from 15 centres. The primary objective was to evaluate if vorinostat was followed by a decline in clonal myeloproliferation as defined by European Leukaemia Net. Thirty patients (48%) completed the intervention period (24 weeks of therapy). An intention-to-treat response rate of 35% was identified. Pruritus was resolved [19% to 0% (P = 0·06)] and the prevalence of splenomegaly was lowered from 50% to 27% (P = 0·03). Sixty-five per cent of the patients experienced a decrease in JAK2 V617F allele burden (P = 0·006). Thirty-three patients (52% of patients) discontinued study drug before end of intervention due to adverse events (28 patients) or lack of response (5 patients). In conclusion, vorinostat showed effectiveness by normalizing elevated leucocyte and platelet counts, resolving pruritus and significantly reducing splenomegaly. However, vorinostat was associated with significant side effects resulting in a high discontinuation rate. A lower dose of vorinostat in combination with conventional and/or novel targeted therapies may be warranted in future studies.

Patients with polycythemia vera have worst impairment of quality of life among patients with newly diagnosed myeloproliferative neoplasms.

The quality of life (QoL) at the time of diagnosis of myeloproliferative neoplasm (MPN) has, to date, not been studied. One hundred and seventy-nine patients with MPN: 80 with essential thrombocythemia (ET), 73 with polycythemia vera (PV), 22 with primary myelofibrosis (PMF) and four with MPN undifferentiated, were included in this study. European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQC30) and the MPN-Symptom Assessment Form (MPN-SAF) were used to evaluate QoL. Fatigue was the most reported symptom in these patients. Patients with PV reported significantly higher mean scores for inactivity, dizziness, cough, itching, depression and lower total QoL compared to patients with ET. Patients with PV had significantly more headache and itching compared to patients with PMF. When the newly diagnosed patients with MPN were compared with a cohort of patients with MPN with mean disease duration of 7.8 years, the differences were most striking for patients with PMF, with significantly more fatigue, abdominal discomfort, concentration problems, insomnia, fever, weight loss and lower overall QoL developed over time.

Diagnosis according to World Health Organization determines the long-term prognosis in patients with myeloproliferative neoplasms treated with anagrelide: results of a prospective long-term follow-up.

OBJECTIVES: During long term follow-up of a cohort of patients with essential thrombocythemia (ET) and polycythemia vera (PV) a higher than expected incidence of myelofibrosis (MF) was noted. In order to test if the explanation could be found in the diagnostic criteria a re-evaluation of diagnosis using the 2008 WHO diagnostic criteria for ET and MF was performed. METHODS: This prospective study of 60 patients with ET and PV was set up in 1998 to evaluate the long-term efficacy and tolerability of anagrelide treatment. Bone marrow trephine biopsies were requested from study start, after 2 and 7 years of follow-up. A blinded re-evaluation of the bone marrow trephines was performed. The 2008 WHO bone marrow criteria were used for diagnosis and fibrosis grading. RESULTS: Of 40 patients with an initial diagnosis of ET, 21 were confirmed as 'true ET' whereas 17 were reclassified as primary myelofibrosis (PMF) (12 PMF-0, 3 PMF-1, 2 PMF-2) and 2 as myeloproliferative neoplasms of uncertain origin. After 7 years of follow-up, 19 of 21 patients with 'true ET' were alive, none had transformed to MF, leukemia, or myelodysplastic syndrome. In contrast, 4/17 patients reclassified as PMF had died, two patients transformed to myelodysplastic syndrome and 7 patients progressed to overt MF. DISCUSSION: We conclude that a blinded re-evaluation of bone marrow trephines from study start and after 7 years of follow-up using 2008 World Health Organization criteria was able to differentiate between true ET and PMF with a marked difference in follow-up outcome.

Clinical effect of increasing doses of lenalidomide in high-risk myelodysplastic syndrome and acute myeloid leukemia with chromosome 5 abnormalities.

BACKGROUND: Patients with chromosome 5 abnormalities and high-risk myelodysplastic syndromes or acute myeloid leukemia have a poor outcome. We hypothesized that increasing doses of lenalidomide may benefit this group of patients by inhibiting the tumor clone, as assessed by fluorescence in situ hybridization for del(5q31). DESIGN AND METHODS: Twenty-eight patients at diagnosis or with relapsed disease and not eligible for standard therapy (16 with acute myeloid leukemia, 12 with intermediate-risk 2 or high-risk myelodysplastic syndrome) were enrolled in this prospective phase II multicenter trial and treated with lenalidomide up to 30 mg daily for 16 weeks. Three patients had isolated del(5q), six had del(5q) plus one additional aberration, 14 had del(5q) and a complex karyotype, four had monosomy 5, and one had del(5q) identified by fluorescence in situ hybridization only. RESULTS: Major and minor cytogenetic responses, assessed by fluorescence in situ hybridization, were achieved in 5/26 (19%) and 2/26 (8%) patients, respectively, who received one or more dose of lenalidomide, while two patients achieved only a bone marrow response. Nine of all 26 patients (35%) and nine of the ten who completed the 16 weeks of trial responded to treatment. Using the International Working Group criteria for acute myeloid leukemia and myelodysplastic syndrome the overall response rate in treated patients with acute myeloid leukemia was 20% (3/15), while that for patients with myelodysplastic syndrome was 36% (4/11). Seven patients stopped therapy due to progressive disease and nine because of complications, most of which were disease-related. Response rates were similar in patients with isolated del(5q) and in those with additional aberrations. Interestingly, patients with TP53 mutations responded less well than those without mutations (2/13 versus 5/9, respectively; P=0.047). No responses were observed among 11 cases with deleterious TP53 mutations. CONCLUSIONS: Our data support a role for higher doses of lenalidomide in poor prognosis patients with myelodysplastic syndrome and acute myeloid leukemia with deletion 5q. (Clinicaltrials.gov identifier NCT00761449).

Acquired haemophilia A and Kaposi's sarcoma in an HIV-negative, HHV-8-positive patient: a discussion of mechanism and aetiology.

BACKGROUND: Acquired haemophilia A (AHA) is a rare bleeding disorder caused by an imbalance in the immune system leading to the production of factor VIII antibodies. In half of the cases, the underlying cause is not known. CLINICAL HISTORY: We report on a patient with AHA and Kaposi's sarcoma (KS), which is caused by the human herpes virus 8 (HHV-8). The patient presented with appendicitis and developed several severe post-operative haemorrhages. He spent 3 months in intensive care due to long and difficult infections. While recuperating on the ward, the patient developed KS in the lower extremities. He had a positive HHV-8 infection. DISCUSSION/CONCLUSION: Due to its latency and replication in the lymphoid system, HHV-8 is an ideal candidate for causing an imbalance in the immune system in susceptible patients. Our conclusion is that AHA was caused or prompted by the HHV-8 infection. Since HHV-8 viral infection is often subclinical, viral testing might be an important tool in acquired haemophilia diagnostics even when viral symptoms are absent.

Obesity and risk for chronic renal failure.

Few large-scale epidemiologic studies have quantified the possible link between obesity and chronic renal failure (CRF). This study analyzed anthropometric data from a nationwide, population-based, case-control study of incident, moderately severe CRF. Eligible as cases were all native Swedes who were aged 18 to 74 yr and had CRF and whose serum creatinine for the first time and permanently exceeded 3.4 mg/dl (men) or 2.8 mg/dl (women) during the study period. A total of 926 case patients and 998 control subjects, randomly drawn from the study base, were enrolled. Face-to-face interviews, supplemented with self-administered questionnaires, provided information about anthropometric measures and other lifestyle factors. Logistic regression models with adjustments for several co-factors estimated the relative risk for CRF in relation to body mass index (BMI). Overweight (BMI>or=25 kg/m2) at age 20 was associated with a significant three-fold excess risk for CRF, relative to BMI<25. Obesity (BMI>or=30) among men and morbid obesity (BMI>or=35) among women anytime during lifetime was linked to three- to four-fold increases in risk. The strongest association was with diabetic nephropathy, but two- to three-fold risk elevations were observed for all major subtypes of CRF. Analyses that were confined to strata without hypertension or diabetes revealed a three-fold increased risk among patients who were overweight at age 20, whereas the two-fold observed risk elevation among those who had a highest lifetime BMI of >35 was statistically nonsignificant. Obesity seems to be an important-and potentially preventable-risk factor for CRF. Although hypertension and type 2 diabetes are important mediators, additional pathways also may exist.

Association between smoking and chronic renal failure in a nationwide population-based case-control study.

For determining whether smoking is associated with an increased risk for chronic renal failure (CRF) overall and by type of renal disease, smoking data were analyzed from a nationwide population-based case-control study. Eligible as cases were native 18- to 74-yr-old Swedes whose serum creatinine for the first time and permanently exceeded 3.4 mg/dl (men) or 2.8 mg/dl (women). A total of 926 cases (78% of all eligible) and 998 control subjects (75% of 1330 randomly selected subjects from the source population), frequency matched to the cases by gender and age within 10 yr, were included. A face-to-face interview and a self-administered questionnaire provided information about smoking habits and other lifestyle factors. Logistic regression models estimated odds ratios (OR) as measures of relative risk for disease-specific types of CRF among smokers compared with never-smokers. Despite a modest and nonsignificant overall association, the risk increased with high daily doses (OR among smokers of >20 cigarettes/d, 1.51; 95% confidence interval [CI], 1.06 to 2.15), long duration (OR among smokers for >40 yr, 1.45; 95% CI, 1.00 to 2.09), and a high cumulative dose (OR among smokers with >30 pack-years, 1.52; 95% CI, 1.08 to 2.14). Smoking increased risk most strongly for CRF classified as nephrosclerosis (OR among smokers with >20 pack-years, 2.2; 95% CI, 1.3 to 3.8), but significant positive associations were also noted with glomerulonephritis. This study thus suggests that heavy cigarette smoking increases the risk of CRF for both men and women, at least CRF classified as nephrosclerosis and glomerulonephritis.

Absence of association between organic solvent exposure and risk of chronic renal failure: a nationwide population-based case-control study.

Exposure to organic solvents has been suggested to cause or exacerbate renal disease, but methodologic concerns regarding previous studies preclude firm conclusions. We examined the role of organic solvents in a population-based case-control study of early-stage chronic renal failure (CRF). All native Swedish residents aged 18 to 74 yr, living in Sweden between May 1996 and May 1998, formed the source population. Incident cases of CRF in a pre-uremic stage (n = 926) and control subjects (n = 998), randomly selected from the study base, underwent personal interviews that included a detailed occupational history. Expert rating by a certified occupational hygienist was used to assess organic solvent exposure intensity and duration. Relative risks were estimated by odds ratios (OR) in logistic regression models, with adjustment for potentially important covariates. The overall risk for CRF among subjects ever exposed to organic solvents was virtually identical to that among never-exposed (OR, 1.01; 95% confidence interval [CI], 0.81 to 1.25). No dose-response relationships were observed for lifetime cumulative solvent exposure, average dose, or exposure frequency or duration. The absence of association pertained to all subgroups of CRF: glomerulonephritis (OR, 0.96; 95% CI, 0.68 to 1.34), diabetic nephropathy (OR, 1.02; 95% CI, 0.74 to 1.41), renal vascular disease (OR, 1.16; 95% CI, 0.76 to 1.75), and other renal CRF (OR, 0.92; 95% CI, 0.66 to 1.27). The results from a nationwide, population-based study do not support the hypothesis of an adverse effect of organic solvents on CRF development, in general. Detrimental effects from subclasses of solvents or on specific renal diseases cannot be ruled out.

Socio-economic status and chronic renal failure: a population-based case-control study in Sweden.

BACKGROUND: Low socio-economic status is associated with the occurrence of several different chronic diseases, but evidence regarding renal disease is scant. To explore whether the risk of chronic renal failure varies by socio-economic status, we performed a population-based case-control study in Sweden. METHODS: All native residents from May 1996 to May 1998, aged 18-74 years, formed the source population. Cases (n = 926) were incident patients with chronic renal failure in a pre-uraemic stage. Control subjects (n = 998) were randomly selected within the source population. Exposures were assessed at personal interviews and relative risks were estimated by odds ratios (OR) in logistic regression models, with adjustment for age, sex, body mass index (BMI), smoking, alcohol consumption and regular analgesics use. RESULTS: In families with unskilled workers only, the risk of chronic renal failure was increased by 110% [OR = 2.1; 95% confidence interval (CI), 1.1-4.0] and 60% (OR = 1.6; 95% CI, 1.0-2.6) among women and men, respectively, relative to subjects living in families in which at least one member was a professional. Subjects with 9 years or less of schooling had a 30% (OR = 1.3; 95% CI, 1.0-1.7) higher risk compared with those with a university education. The excess risk was of similar magnitude regardless of underlying renal disease. CONCLUSIONS: Low socio-economic status is associated with an increased risk of chronic renal failure. The moderate excess was not explained by age, sex, BMI, smoking, alcohol or analgesic intake. Thus, socio-economic status appears to be an independent risk indicator for chronic renal failure in Sweden.