Privacy-preserving record linkage across disparate institutions and datasets to enable a learning health system: The national COVID cohort collaborative (N3C) experience

Introduction

Research driven by real-world clinical data is increasingly vital to enabling learning health systems, but integrating such data from across disparate health systems is challenging. As part of the NCATS National COVID Cohort Collaborative (N3C), the N3C Data Enclave was established as a centralized repository of deidentified and harmonized COVID-19 patient data from institutions across the US. However, making this data most useful for research requires linking it with information such as mortality data, images, and viral variants. The objective of this project was to establish privacy-preserving record linkage (PPRL) methods to ensure that patient-level EHR data remains secure and private when governance-approved linkages with other datasets occur.

Methods

Separate agreements and approval processes govern N3C data contribution and data access. The Linkage Honest Broker (LHB), an independent neutral party (the Regenstrief Institute), ensures data linkages are robust and secure by adding an extra layer of separation between protected health information and clinical data. The LHB's PPRL methods (including algorithms, processes, and governance) match patient records using "deidentified tokens," which are hashed combinations of identifier fields that define a match across data repositories without using patients' clear-text identifiers.

Results

These methods enable three linkage functions: Deduplication, Linking Multiple Datasets, and Cohort Discovery. To date, two external repositories have been cross-linked. As of March 1, 2023, 43 sites have signed the LHB Agreement; 35 sites have sent tokens generated for 9 528 998 patients. In this initial cohort, the LHB identified 135 037 matches and 68 596 duplicates.

Conclusion

This large-scale linkage study using deidentified datasets of varying characteristics established secure methods for protecting the privacy of N3C patient data when linked for research purposes. This technology has potential for use with registries for other diseases and conditions.

Harmonizing units and values of quantitative data elements in a very large nationally pooled electronic health record (EHR) dataset

Objective

The goals of this study were to harmonize data from electronic health records (EHRs) into common units, and impute units that were missing.

Materials and Methods

The National COVID Cohort Collaborative (N3C) table of laboratory measurement data—over 3.1 billion patient records and over 19 000 unique measurement concepts in the Observational Medical Outcomes Partnership (OMOP) common-data-model format from 55 data partners. We grouped ontologically similar OMOP concepts together for 52 variables relevant to COVID-19 research, and developed a unit-harmonization pipeline comprised of (1) selecting a canonical unit for each measurement variable, (2) arriving at a formula for conversion, (3) obtaining clinical review of each formula, (4) applying the formula to convert data values in each unit into the target canonical unit, and (5) removing any harmonized value that fell outside of accepted value ranges for the variable. For data with missing units for all the results within a lab test for a data partner, we compared values with pooled values of all data partners, using the Kolmogorov-Smirnov test.

Results

Of the concepts without missing values, we harmonized 88.1% of the values, and imputed units for 78.2% of records where units were absent (41% of contributors’ records lacked units).

Discussion

The harmonization and inference methods developed herein can serve as a resource for initiatives aiming to extract insight from heterogeneous EHR collections. Unique properties of centralized data are harnessed to enable unit inference.

Conclusion

The pipeline we developed for the pooled N3C data enables use of measurements that would otherwise be unavailable for analysis.

Synergies between centralized and federated approaches to data quality: a report from the national COVID cohort collaborative

OBJECTIVE

In response to COVID-19, the informatics community united to aggregate as much clinical data as possible to characterize this new disease and reduce its impact through collaborative analytics. The National COVID Cohort Collaborative (N3C) is now the largest publicly available HIPAA limited dataset in US history with over 6.4 million patients and is a testament to a partnership of over 100 organizations.

MATERIALS AND METHODS

We developed a pipeline for ingesting, harmonizing, and centralizing data from 56 contributing data partners using 4 federated Common Data Models. N3C data quality (DQ) review involves both automated and manual procedures. In the process, several DQ heuristics were discovered in our centralized context, both within the pipeline and during downstream project-based analysis. Feedback to the sites led to many local and centralized DQ improvements.

RESULTS

Beyond well-recognized DQ findings, we discovered 15 heuristics relating to source Common Data Model conformance, demographics, COVID tests, conditions, encounters, measurements, observations, coding completeness, and fitness for use. Of 56 sites, 37 sites (66%) demonstrated issues through these heuristics. These 37 sites demonstrated improvement after receiving feedback.

DISCUSSION

We encountered site-to-site differences in DQ which would have been challenging to discover using federated checks alone. We have demonstrated that centralized DQ benchmarking reveals unique opportunities for DQ improvement that will support improved research analytics locally and in aggregate.

CONCLUSION

By combining rapid, continual assessment of DQ with a large volume of multisite data, it is possible to support more nuanced scientific questions with the scale and rigor that they require.

Clinical Characterization and Prediction of Clinical Severity of SARS-CoV-2 Infection Among US Adults Using Data From the US National COVID Cohort Collaborative

Importance

The National COVID Cohort Collaborative (N3C) is a centralized, harmonized, high-granularity electronic health record repository that is the largest, most representative COVID-19 cohort to date. This multicenter data set can support robust evidence-based development of predictive and diagnostic tools and inform clinical care and policy.

Objectives

To evaluate COVID-19 severity and risk factors over time and assess the use of machine learning to predict clinical severity.

Design, Setting, and Participants

In a retrospective cohort study of 1 926 526 US adults with SARS-CoV-2 infection (polymerase chain reaction >99% or antigen <1%) and adult patients without SARS-CoV-2 infection who served as controls from 34 medical centers nationwide between January 1, 2020, and December 7, 2020, patients were stratified using a World Health Organization COVID-19 severity scale and demographic characteristics. Differences between groups over time were evaluated using multivariable logistic regression. Random forest and XGBoost models were used to predict severe clinical course (death, discharge to hospice, invasive ventilatory support, or extracorporeal membrane oxygenation).

Main Outcomes and Measures

Patient demographic characteristics and COVID-19 severity using the World Health Organization COVID-19 severity scale and differences between groups over time using multivariable logistic regression.

Results

The cohort included 174 568 adults who tested positive for SARS-CoV-2 (mean [SD] age, 44.4 [18.6] years; 53.2% female) and 1 133 848 adult controls who tested negative for SARS-CoV-2 (mean [SD] age, 49.5 [19.2] years; 57.1% female). Of the 174 568 adults with SARS-CoV-2, 32 472 (18.6%) were hospitalized, and 6565 (20.2%) of those had a severe clinical course (invasive ventilatory support, extracorporeal membrane oxygenation, death, or discharge to hospice). Of the hospitalized patients, mortality was 11.6% overall and decreased from 16.4% in March to April 2020 to 8.6% in September to October 2020 (P = .002 for monthly trend). Using 64 inputs available on the first hospital day, this study predicted a severe clinical course using random forest and XGBoost models (area under the receiver operating curve = 0.87 for both) that were stable over time. The factor most strongly associated with clinical severity was pH; this result was consistent across machine learning methods. In a separate multivariable logistic regression model built for inference, age (odds ratio [OR], 1.03 per year; 95% CI, 1.03-1.04), male sex (OR, 1.60; 95% CI, 1.51-1.69), liver disease (OR, 1.20; 95% CI, 1.08-1.34), dementia (OR, 1.26; 95% CI, 1.13-1.41), African American (OR, 1.12; 95% CI, 1.05-1.20) and Asian (OR, 1.33; 95% CI, 1.12-1.57) race, and obesity (OR, 1.36; 95% CI, 1.27-1.46) were independently associated with higher clinical severity.

Conclusions and Relevance

This cohort study found that COVID-19 mortality decreased over time during 2020 and that patient demographic characteristics and comorbidities were associated with higher clinical severity. The machine learning models accurately predicted ultimate clinical severity using commonly collected clinical data from the first 24 hours of a hospital admission.

The National COVID Cohort Collaborative (N3C): Rationale, design, infrastructure, and deployment

Objective

Coronavirus disease 2019 (COVID-19) poses societal challenges that require expeditious data and knowledge sharing. Though organizational clinical data are abundant, these are largely inaccessible to outside researchers. Statistical, machine learning, and causal analyses are most successful with large-scale data beyond what is available in any given organization. Here, we introduce the National COVID Cohort Collaborative (N3C), an open science community focused on analyzing patient-level data from many centers.

Materials and Methods

The Clinical and Translational Science Award Program and scientific community created N3C to overcome technical, regulatory, policy, and governance barriers to sharing and harmonizing individual-level clinical data. We developed solutions to extract, aggregate, and harmonize data across organizations and data models, and created a secure data enclave to enable efficient, transparent, and reproducible collaborative analytics.

Results

Organized in inclusive workstreams, we created legal agreements and governance for organizations and researchers; data extraction scripts to identify and ingest positive, negative, and possible COVID-19 cases; a data quality assurance and harmonization pipeline to create a single harmonized dataset; population of the secure data enclave with data, machine learning, and statistical analytics tools; dissemination mechanisms; and a synthetic data pilot to democratize data access.

Conclusions

The N3C has demonstrated that a multisite collaborative learning health network can overcome barriers to rapidly build a scalable infrastructure incorporating multiorganizational clinical data for COVID-19 analytics. We expect this effort to save lives by enabling rapid collaboration among clinicians, researchers, and data scientists to identify treatments and specialized care and thereby reduce the immediate and long-term impacts of COVID-19.

The National COVID Cohort Collaborative: Clinical Characterization and Early Severity Prediction

Background:

The majority of U.S. reports of COVID-19 clinical characteristics, disease course, and treatments are from single health systems or focused on one domain. Here we report the creation of the National COVID Cohort Collaborative (N3C), a centralized, harmonized, high-granularity electronic health record repository that is the largest, most representative U.S. cohort of COVID-19 cases and controls to date. This multi-center dataset supports robust evidence-based development of predictive and diagnostic tools and informs critical care and policy.

Methods and Findings:

In a retrospective cohort study of 1,926,526 patients from 34 medical centers nationwide, we stratified patients using a World Health Organization COVID-19 severity scale and demographics; we then evaluated differences between groups over time using multivariable logistic regression. We established vital signs and laboratory values among COVID-19 patients with different severities, providing the foundation for predictive analytics. The cohort included 174,568 adults with severe acute respiratory syndrome associated with SARS-CoV-2 (PCR >99% or antigen <1%) as well as 1,133,848 adult patients that served as lab-negative controls. Among 32,472 hospitalized patients, mortality was 11.6% overall and decreased from 16.4% in March/April 2020 to 8.6% in September/October 2020 (p = 0.002 monthly trend). In a multivariable logistic regression model, age, male sex, liver disease, dementia, African-American and Asian race, and obesity were independently associated with higher clinical severity. To demonstrate the utility of the N3C cohort for analytics, we used machine learning (ML) to predict clinical severity and risk factors over time. Using 64 inputs available on the first hospital day, we predicted a severe clinical course (death, discharge to hospice, invasive ventilation, or extracorporeal membrane oxygenation) using random forest and XGBoost models (AUROC 0.86 and 0.87 respectively) that were stable over time. The most powerful predictors in these models are patient age and widely available vital sign and laboratory values. The established expected trajectories for many vital signs and laboratory values among patients with different clinical severities validates observations from smaller studies, and provides comprehensive insight into COVID-19 characterization in U.S. patients.

Conclusions:

This is the first description of an ongoing longitudinal observational study of patients seen in diverse clinical settings and geographical regions and is the largest COVID-19 cohort in the United States. Such data are the foundation for ML models that can be the basis for generalizable clinical decision support tools. The N3C Data Enclave is unique in providing transparent, reproducible, easily shared, versioned, and fully auditable data and analytic provenance for national-scale patient-level EHR data. The N3C is built for intensive ML analyses by academic, industry, and citizen scientists internationally. Many observational correlations can inform trial designs and care guidelines for this new disease.

First Molecular Identification and Genetic Characterization of Theileria lestoquardi in Sheep of the Maghreb Region

Theileria lestoquardi is the most prominent Theileria species in small ruminants that causes malignant theileriosis of sheep in Africa and Asia. In the present survey, blood samples and ticks were collected in Kebili (southern Tunisia) from 166 Queue Fine de l'Ouest sheep. Giemsa-stained blood smears, immunofluorescent antibody test (IFAT) and PCR were performed. The DNA was extracted from blood and analysed by PCR targeting 18S rRNA gene of Theileria spp. and then sequenced. A total number of 140 ticks were collected from a total number of 166 sheep during the four seasons. The ticks belonged to two genera and 4 species; the most frequent tick was Hyalomma excavatum 84.3% (118/140) and then Rhipicephalus spp. 15.7% (22/140). Only two animals had positive Giemsa-stained blood smears, and they were also positive by IFAT. The amplicons had 99.3 and 99.6% homology with the BLAST published T. lestoquardi amplicons. To our knowledge, this is the first report of T. lestoquardi in small ruminants within the Maghreb region.

Uncovering allosteric pathways in caspase-1 using Markov transient analysis and multiscale community detection

Atomistic graph–theoretical analysis of caspase-1 reveals details of intra-protein communication pathways.

Phenotypic diversity is not determined by independent genetic factors in familial spondylarthropathy

OBJECTIVE

To analyze the segregation of manifestations belonging to the spectrum of spondylarthropathy (SpA) among patients and unaffected siblings within SpA multiplex families.

METHODS

Ninety-five multiplex families have been investigated. The diagnosis of SpA was made according to European Spondylarthropathy Study Group criteria. The prevalence of SpA manifestations was determined in unaffected siblings and compared with their prevalence in patients.

RESULTS

We compared 241 SpA patients with 259 unaffected siblings. The prevalence of skeletal and extraarticular features not used as diagnostic criteria, i.e., radiographic sacroiliitis, peripheral enthesitis, uveitis, psoriasis, and inflammatory bowel disease, was significantly increased in patients compared with unaffected siblings. This result was not accounted for by sex or HLA-B27 distribution differences.

CONCLUSION

In familial SpA, skeletal and extraarticular manifestations tend to segregate together, implying that all subsets are predominantly determined by a shared component, and that accessory factors must be responsible for phenotype diversity.

What competence does a rheumatologist need?: an international perspective

OBJECTIVES

To forecast, on the basis of the past and present position of rheumatologists in Europe, the competence needed in the future to secure and promote the specialty within the healthcare network.

METHODS

Union Européenne des Médecins Spécialistes/European Board of Rheumatology (UEMS/EBR) questionnaire on (a) training centres in Europe, (b) rheumatologists' skills, (c) UEMS core curriculum.

RESULTS

173 training centres in rheumatology were identified. Reponses to the questionnaire showed both harmony and diversity in the practice of rheumatology. Harmony arises from the need to (a) have an extensive and profound knowledge of, and clinical experience with, all the causes of painful or disabled locomotor apparatus; (b) manage such disorders in the most cost effective way; and (c) promote "shared clinical decision making". The diversity seen both among and within the European countries is due to the different activities of rheumatologists.

CONCLUSION

Rheumatological competence must be based on a common core, as described in the UEMS core curriculum, and on deeper and diverse clinical or scientific knowledge covering the entire field of the specialty, to secure its flexibility and resilience in the market place and to promote its scientific development.

The familial form of spondylarthropathy: a clinical study of 115 multiplex families. Groupe Français d'Etude Génétique des Spondylarthropathies

OBJECTIVE

To investigate the interrelationships among different phenotypes, and their relationship to the HLA-Blocus, in multiplex families with spondylarthropathy (SpA).

METHODS

We recruited 115 white French families, each of which had at least 2 members with SpA. Pedigrees were established. Clinical data and pelvic radiographs were collected. The HLA-B27 status of all patients was determined. Analysis was performed to determine the prevalence of SpA manifestations according to sex, disease duration, and HLA-B status, and to examine clustering of specific manifestations in subsets of families.

RESULTS

We identified 329 SpA patients. Mean +/-SD age at onset was 24+/-9.4 years. The male:female ratio was 186:143, or 1.3, with few sex differences in disease expression. Axial manifestations and HLA-B27 were each present in 97% of the patients. Inflammatory bowel disease and HLA-B35 were overrepresented in the 7 families containing HLA-B27-negative patients. The frequency of radiographic sacroiliitis increased in parallel with disease duration. Peripheral enthesitis, radiographic sacroiliitis, and psoriasis were evenly distributed in the families. Clustering independent of age was only observed for peripheral arthritis, suggesting that specific factors may predispose individuals to this manifestation.

CONCLUSION

Familial SpA appears to be homogeneous, based on the high frequencies of axial skeletal involvement and HLA-B27. The lack of clustering of most manifestations in families suggests that a predominant shared component, including HLA-B27, predisposes individuals to all forms of familial SpA, and that ubiquitous genetic or environmental factors contribute to phenotype diversity.

Concordance between abdominal scintigraphy using technetium-99m hexamethylpropylene amine oxime-labelled leucocytes and ileocolonoscopy in patients with spondyloarthropathies and without clinical evidence of inflammatory bowel disease

OBJECTIVE

To study the concordance between abdominal scintigraphy using technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocytes (ASTLL) and ileocolonoscopy in patients with spondyloarthropathies (SpA) and without clinical evidence of inflammatory bowel disease (IBD).

PATIENTS AND METHODS

Fifteen patients with SpA (European Spondylarthropathy Study Group 1991 criteria) without clinical evidence of IBD were studied prospectively with ASTLL and ileocolonoscopy.

RESULTS

This cohort consisted of seven men and eight women aged 31.8+/-10.5 yr (18-47) [mean age +/- S.D. (range)] and with a disease duration of 6.0+/-4.4 yr (0.4-15). ASTLL showed abnormal uptake in four patients. Ileocolonoscopy was abnormal in five patients, showing acute inflammatory lesions in one patient with reactive arthritis, undifferentiated chronic inflammatory lesions in two cases, and features indistinguishable from those of Crohn's disease in two cases. ASTLL was negative in two cases in which ileocolonoscopy showed inflammatory lesions and was positive (terminal ileum) in one case with normal ileocolonoscopy. The concordance between the two examinations was statistically significant (kappa = 0.53; P = 0.008).

CONCLUSION

ASTLL may be an interesting tool to detect subclinical gut inflammation in patients with SpA.

Are radiological joint space widths of normal hips asymmetrical?

BACKGROUND

To be certain that the joint space width is abnormal in the case of hip joint pain when compared with the contralateral hip requires knowledge of physiological dissymmetry.

AIM OF THE STUDY

To assess interindividual variability and dissymmetry in pelvic radiological joint space width.

METHODS

Pelvic radiographs of subjects without hip joint disease. Measurement with a 0.1 mm graduated magnifying glass and 0.5 mm graduated flat ruler at the hip superointermediate site (vertical going through the femoral head centre). After randomisation of the side to measure, analysis of nine groups of 19 plain films by one investigator blind for the result of the contralateral side.

RESULTS

The difference between the left and right hip was plotted against the corresponding mean for all 171 normal subjects. This shows the frequency and the limits of the asymmetry at each measurement site. The asymmetry is independent of interindividual variability of the joint space width and greater than the measurement error in most subjects.

CONCLUSION

This study confirms the interindividual variability of hip joint space width, shows the frequency of hip joint space asymmetry and defines its limit.

Piroxicam therapy: a double blind, randomized, multicenter study comparing 2 versus 4 week treatment in patients with painful knee osteoarthritis with effusion

OBJECTIVE

To compare the efficacy and safety of piroxicam 20 mg once a day for 14 or 28 days in patients with knee osteoarthritis (OA) and synovial effusion.

METHODS

We conducted a multicenter, randomized, double blind study in 1905 outpatients. Efficacy was assessed by changes in synovial effusion, pain on a 100 mm visual analog scale (VAS), and impairment using Lequesne's functional index. Patients were classified at Day 28 as improved (defined as VAS and Lequesne index decrease of at least 30% from Day 14), worsened (defined as VAS and Lequesne index increase of at least 30% from Day 14), or unchanged. Safety was assessed on the basis of adverse events reported by the patients.

RESULTS

After 14 days, changes in pain, synovial effusion, and functional impairment significantly decreased from baseline within each group (p < 0.001, respectively), but did not differ between the groups. Between 14 and 28 days, outcome measure changes were significantly better in the 28 day group, p = 0.01, 0.0001, and 0.0001, respectively. In the 28 day and 14 day groups, improvement with regard to pain was observed for 339 (52.4%) and 280 (29.4%) patients, respectively, (p < 0.0001), and with regard to functional impairment for 298 (31.5%) and 233 (24.3%) patients (p < 0.0001). Adverse events accounted for 7.5 and 6.7% of withdrawals in the 28 day and 14 day groups, respectively.

CONCLUSION

When administration of piroxicam 20 mg is prolonged to 28 days, continuing benefit is observed for some patients with knee OA with painful synovial effusion without a significant difference in safety.

Reiter's syndrome. Diagnosis and clinical features

After a short review of the history of Reiter's diseases, new definitions of what is now called reactive arthritis are proposed. The best definition is based on a multiple-entry set of criteria validated by other members of the spondyloarthropathy group. This definition needs no reference to origin hypothesis and no exclusion criteria. The epidemiology of Reiter's syndrome is also discussed, and the problems due to previously imprecise definitions are emphasized. Clinical features are described and divided into four syndromes: peripheral arthritis, enthesopathic, pelvic and axial, and extramusculoskeletal syndromes; seven predictive factors of long-term evolution are proposed. Differential diagnosis is discussed within and without the spondyloarthropathy group.

Arthroscopic evaluation of potential structure modifying activity of hyaluronan (Hyalgan) in osteoarthritis of the knee

OBJECTIVE

Several reported studies suggest that repeated intra-articular injections of hyaluronan result in sustained relief from pain and functional disability in patients with knee osteoarthritis. Several in vivo data suggest that hyaluronan might have a beneficial structural effect in osteoarthritis. The objective of the study was to evaluate the potential structure-modifying effects of Hyalgan (500-730 kDa molecular weight), a highly-purified sodium hyaluronate.

DESIGN

Patients with painful knee osteoarthritis (ACR criteria) were enrolled in a prospective, controlled study of 1-year duration. After randomization, either conventional therapy or three cycles (every 3 months) of three intra-articular injections of Hyalgan (once a week during 2 weeks) were given. Clinical outcome was added using pain visual analog score (VAS), functional impairment: Lequesne's index, quality of life: arthritis impact measurement scale (AIMS2) and structural outcome using X-rays: joint space narrowing and arthroscopy: global assessment using VAS, SFA scoring and grading systems.

RESULTS

Of the 39 recruited patients, 36 completed the 1-year trial (19 in the Hyalgan group and 17 in the control group). There was no difference between groups at entry. Between-group comparison for changes in clinical parameters reached statistical significance for the quality of life index (AIMS2: -0.4 +/- 0.7 vs 0.2 +/- 0.9 in the Hyalgan and control groups respectively, P < 0.05). Deterioration in the structural parameters was less in the Hyalgan group, with a statistically significant difference for two of the three evaluated parameters (overall assessment of chondropathy: +5.1 +/- 12.7 vs 16.7 +/- 18.3, P = 0.016; SFA scoring system: +3.7 +/- 7.3 vs +9.0 +/- 11.5, P = 0.05) in the Hyalgan and control groups, respectively.

CONCLUSIONS

This study supports existing data concerning the favorable symptomatic effect of intra-articular injections of Hyalgan in osteoarthritis of the knee and suggests that repeated intra-articular injections of Hyalgan might delay the structural progression of the disease. Other studies are required to confirm these results and to determine the long-term monitoring of osteoarthritic patients using such local therapy.

Arthroscopy-assisted synovectomy in the treatment of chronic synovitis of the knee

The place of arthroscopy-assisted synovectomy in the treatment of inflammatory synovitis of the knee was evaluated by studying 26 patients who underwent this procedure between November 1992 and September 1995. Half the patients had rheumatoid arthritis. Twenty-three patients (28 knees) were reevaluated after a mean follow-up of 32 months (range, 4-50 months). The arthroscopic synovectomy was done either as the first-line synovectomy procedure, after failure of triamcinolone hexacetonide injection into the joint, or as the second-line synovectomy procedure, after failure of osmic acid or yttrium-90 synovectomy. Except in one patient with severe arthritis, arthroscopic synovectomy produced statistically significant improvements regarding pain (visual scale), function (Lequesne's index), range of flexion, amount of joint fluid and knee circumference. The range of extension of the knee was normal at baseline and remained so after the procedure. Overall efficacy was similar for first-line and second-line procedures. Results were rated good to very good by 71% of the patients and 61% of the physicians overall and the overall improvement in knee arthritis as perceived by the patients was 60%. The procedure was well tolerated in 93% of cases. The mean time needed to achieve a stable improvement was 3.2 weeks for pain, 4.7 weeks for swelling and 3.6 weeks for range of motion. One case each of hemarthrosis and stiffness of the knee were recorded, with a full recovery in both cases. Arthroscopic synovectomy is effective and safe but more burdensome and expensive than osmic acid or radiation synovectomy, and consequently deserves a place of choice in patients who have failed to respond to either of the last two methods.

Assessment of joint space width in patients with osteoarthritis of the knee: a comparison of 4 measuring instruments

OBJECTIVE

To evaluate the intra and interobserver reproducibility of 4 measuring instruments for assessing joint space width in knee osteoarthritis (OA) and to estimate the effects of patients, instrument, session order, and reader variation.

METHODS

We studied 30 patients with unilateral tibiofemoral OA selected to represent a broad range of radiographic changes. Joint space width (JSW) was measured on plain anteroposterior weight bearing radiographs. Using an experimental design, 3 readers assessed JSW 3 times with 4 measuring instruments (ruler, caliper, graduated magnifying glass, digitized assessment).

RESULTS

Intra and interobserver reproducibility was high with all measuring instruments (intraclass correlation coefficients from 0.95 to 0.98 and from 0.91 to 0.97, respectively). Analysis of variance (ANOVA) showed a patient effect (p < 10(-6)), a reader effect (p = 0.0001), an instrument effect (p = 0.0001), and a session order effect (p = 0.04). The variance component estimates were patients 55%, readers 34%, session order 2%, instruments 8%. ANOVA performed separately for each instrument showed that session order differences always represented less than 1% of the total variance. The reader component accounted for 0% of the total variance for the ruler, 2% for the digitized method, 16% for the caliper, and 18% for the graduated magnifying glass.

CONCLUSION

Ruler and digitized assessment have better reliability than caliper and graduated magnifying glass.

Knee joint space width measurement: an experimental study of the influence of radiographic procedure and joint positioning

We studied the influence of the radiographic procedure and joint positioning on knee joint space width (JSW) in 10 healthy volunteers, and the intrareader reproducibility of JSW measurements on radiographs performed 2 weeks apart using a standardized procedure. Results show that a 5 or 10 downward inclination of the X-ray beam and 15 or 30 of induced external foot rotation significantly reduced JSW. In contrast, knee flexion increased JSW. The mean differences and S.D. in the measurement of JSW between two sets of radiographs taken 2 weeks apart were not statistically significant, ranging from -0.07 mm (S.D. 0.38) to 0.020 mm (S.D. 0.38). Our findings indicate that modifications in knee flexion, foot rotation and X-ray beam inclination influence JSW. Therefore, standardization of joint positioning and of the radiographic procedure is necessary to obtain comparable radiographic images on successive X-rays.

Development and validation of a rheumatoid hand functional disability scale that assesses functional handicap

OBJECTIVE

To construct a functional disability scale for the rheumatoid hand and to determine if this scale also assesses functional handicap.

METHODS

Outpatients and inpatients with rheumatoid arthritis (RA) according to the ACR criteria answered a set of questions on their daily hand activities. Intrarater and interrater reliability were examined. Criterion referenced validity, and convergent and divergent validities were investigated. Factor analysis followed by varimax rotation was performed. Spearman's (rs) correlation coefficients between 2 quantitative variables were examined. The level of significance was p < 0.05.

RESULTS

96 patients with RA were recruited. The provisional scale had 41 questions. The elimination process left 18 hand activity questions with 6 levels of answers. The intrarater and interrater reliabilities of the scale were 0.97 and 0.96, respectively. Correlation of the scale's total score with visual analog scale (VAS) measure of functional handicap (rs = 0.78) showed good criterion referenced validity. The scale had good convergence with Revel's Functional Index (rs = 0.91) and a moderate relation to the Hand Functional Index (HFI) (rs = 0.58). The scale had a moderate, fair, or no relation to age, morning stiffness, pain measures, and hand swelling. The scale had 3 main factors by factor analysis. An English translation of the scale was validated.

CONCLUSION

We have developed a practical functional disability scale for rheumatoid hands that also assesses functional handicap. It has 18 hand activity questions and has been validated in a French population.

Forceful epidural injections for the treatment of lumbosciatic pain with post-operative lumbar spinal fibrosis

OBJECTIVE

To evaluate the efficacy of forceful epidural corticosteroid injections in lumbosciatic pain ascribed to post-operative lumbar spinal fibrosis.

METHOD

Randomized controlled study comparing forceful injections via the sacral hiatus of 125 mg prednisolone acetate + 40 ml saline (treatment group) and injections via the same route of 125 mg prednisolone acetate alone (control group). Results were compared after six and 18 months. The main evaluation criterion was a subjective assessment of overall efficacy done by the patient using a seven-level scale.

RESULTS

After six months, the proportion of patients who were relieved of their sciatica was significantly higher in the forceful injection group (n = 29; 45%) than in the control group (n = 31; 19%) (p = 0.03). Success rates for low back pain were 29% and 6% in the forceful injection and control groups, respectively. Among secondary efficacy criteria, nerve root pain evaluated on a visual analog scale and by Schöber's index showed significantly greater improvement in the forceful injection group than in the control group. After 18 months, results were still in favor of the forceful injection group, with success rates of 39% for the sciatica and 31% for the low back pain. The proportion of patients who returned to work was similar in the two groups.

CONCLUSION

Although mediocre overall, the results of forceful epidural corticosteroid injections are better than those of simple epidural injections of a corticosteroid alone. Given the paucity of effective treatments for lumbosciatic pain apparently due to postoperative fibrosis, forceful injections should be given a place in the treatment of this condition.

Arthroscopic evaluation of chondropathy in osteoarthritis of the knee

OBJECTIVE

To evaluate arthroscopic findings as a potential measurement of severity and outcome of chondropathy.

METHODS

110 patients with knee osteoarthritis (OA) were included in a cross sectional study and 41 of them in a one year longitudinal study. The evaluation of OA performed once in the cross sectional study and twice (at entry and after one year) in the longitudinal study, included clinical, radiological and arthroscopic variables evaluating disease activity and severity. Arthroscopy was performed. under local anesthesia in an outpatient procedure using a small arthroscope. Chondropathy was evaluated by the overall assessment of the investigator by visual analog scale and the Société Française d'Arthroscopie (SFA) scoring and grading systems, which represent a composite index taking into account depth, size, and localization of the articular cartilage lesions.

RESULTS

The intrinsic validity of the arthroscopic variables was suggested by highly significant correlation (R2 = 80-85%) between the overall assessment of the investor and the SFA systems. There was also highly significant correlation (p < 0.01) between the arthroscopic and radiological variables. Intraobserver reliability of the arthroscopic quantification of chondropathy was better than interobserver reliability. In the cross sectional study, severity of chondropathy correlated with both age and body mass index. In the longitudinal study there was statistically significant worsening in the severity of chondropathy and statistically significant correlation between the changes in the severity of chondropathy and changes in functional impairment.

CONCLUSION

We conclude that arthroscopy might be considered a relevant measurement of OA outcome for research purposes.

Features associated with juvenile onset of spondylarthropathies in north Africa

To determine whether juvenile onset of spondylarthropathy is associated with specific features, a prospective, cross-sectional study comparing juvenile-onset and adult-onset spondylarthropathies was conducted in the Maghreb in 523 patients meeting Amor's criteria or the ESSG's criteria for spondylarthropathy. Demographic data and clinical findings at the time of inclusion and during the first two years of the disease were compared in the 437 patients with onset at 16 years of age or older and in the 86 patients with onset before 16 years of age using a Student's t test or a chi-square test. The risk of hip involvement during the course of the disease was estimated using Kaplan-Meier curves and compared in the two groups using a Cox model. Early in the disease, patients in the juvenile onset group were more likely to have peripheral arthritis (52% vs 39%, p = 0.021) and enthesopathies (55% vs 40%, p = 0.002) and less likely to have axial manifestations (41% vs 62%, p = 0.0001), as compared with the adult-onset group. These differences persisted after a follow-up of 9.2 years. Juvenile-onset disease was associated with a greater likelihood of hip involvement (54 +/- 6% vs 34 +/- 3% after ten years, p = 0.012). The male bias was more marked in the juvenile onset group (85%) than in the adult-onset group (72%) (p = 0.016). These data confirm that demographic characteristics, clinical manifestations, and disease severity differ between juvenile-onset and adult-onset spondylarthropathies.

[Imaging of multiple myeloma]

Multiple myeloma (MM) is characterized by a proliferation of plasma cells responsible for osteolytic lesions. Imaging studies are performed in MM to establish diagnosis and prognosis, and may also be used to judge the efficacy of treatment and to detect complications. TO ESTABLISH THE DIAGNOSIS: Conventional radiography demonstrates, at the time of diagnosis, characteristic features in 80% of cases. These lytic lesions involve more often the sites of red marrow. More rarely the only abnormal finding is diffuse osteopenia. Tomodensitometry and, above all, magnetic resonance imaging (MRI), which is a reference method for bone marrow disorders, can be useful for diagnosis in some difficult cases. But the lesions observed, hyposignals on spin echo T1 sequences and hyposignals on T2-weighted gradient echo, are not specific and usually do not allow to distinguish MM from osteolytic metastasis or other bone marrow disorders. TO DETERMINE EXTENT OF DISEASE AND TO EVALUATE PROGNOSIS: According to Durie and Salmon, the extension of home lesions at diagnosis is strongly correlated with the myelomatous measured cellular mass and with survival of patients. But this relation is denied by some authors who have noted that the shortest survival was seen in patients with normal X-rays. TO JUDGE THE EFFICACY OF TREATMENT: Improvement of the radiological abnormalities is observed in nearly 30% of patients responding to a conventional chemotherapy and appears to be an adverse pronostic sign. A good correlation between MRI and the biological response to treatment has also been reported. TO RECOGNIZE COMPLICATIONS OF DISEASE: Conventional radiography is also very important in diagnosis of complications like fractures or vertebral compression. Lastly, MRI is the investigation of first choice in the evaluation of patients with suspected spinal cord compression.

Predictive factors of severity of spondyloarthropathy in North Africa

Both genetic and environmental factors probably influence the severity of Spondyloarthropathies. Hip involvement, which may be used as a marker of disease severity, is more frequent in spondyloarthropathies developed in North Africa. The objective of this study was determine the predisposing factors of hip involvement in spondyloarthropathy in North Africa. Patients fulfilled the Amor or European Spondyloarthropathy Study Group (ESSG) criteria of spondyloarthropathy. The study was retrospective, cross-sectional, multicentre and carried out in North Africa. The data collected were demographic data, socio-cultural factors and clinical presentation at onset. The risk of hip involvement with regard to disease duration was estimated using Kaplan-Meier's method. The predictive value of each variable with regard to time to hip involvement was evaluated using a uni- and then a multivariate Cox proportional hazard model. Five hundred and eighteen patients were included. The risk of hip involvement was estimated at 39+/-3% after 10 yr disease duration. The factors picked up by the multivariate analysis were: diagnostic delay less than 7 yr, age at onset below 24 yr and a combination of 'lower social class' and 'no refrigerator at home'. This study confirms the high prevalence of hip involvement during the course of spondyloarthropathy in North Africa and suggests a role of environmental factors in its appearance.

Predictors of the need for total hip replacement in patients with osteoarthritis of the hip

RATIONALE

the natural history and risk factors for hip osteoarthritis are still unknown.

OBJECTIVE

to identify factors predicting a need for total hip replacement at some time during the course of hip osteoarthritis.

PATIENTS AND METHODS

outpatients evaluated between 1981 and 1986 for hip osteoarthritis were studied retrospectively. The date of diagnosis and the characteristics of the patients and hip disease at diagnosis were recorded. The risk of eventual total hip replacement was estimated using the Kaplan-Meier method. Uni- and multivariate Cox proportional hazard models were used to determine the value of each variable for predicting total hip replacement.

RESULTS

we included 149 patients (50 males). The risk of total hip replacement was estimated at 36 +/- 4% five years after diagnosis. Factors with significant effects in the multivariate analysis were age older than 54 years at diagnosis (relative risk 3.15), body mass index greater than 27 (relative risk 2.97), and severe radiological joint space narrowing at diagnosis (relative risk 2.26).

CONCLUSION

this study confirmed the often severe course of hip osteoarthritis and identified several factors possibly associated with rapid progression.

Bone loss during gonadotropin releasing hormone agonist treatment and use of nasal calcitonin

Gonadotropin releasing hormone (GnRH) agonists have shown to be effective in the treatment of several sex-hormone-dependent conditions. However, their use could be limited by the bone loss they induce. To evaluate the use of nasal salmon calcitonin (sCT) in preventing this bone loss, 40 patients with endometriosis were treated for 6 months with triptoreline (3.75 mg monthly) and calcium (1 g daily), and randomized in three groups-placebo, sCT 100 IU daily and sCT 200 IU daily-in a prospective double-masked study. Dual-energy X-ray absorptiometry and biochemical parameters were used to evaluate the benefit of the treatment. At baseline, there were no statistically significant differences between the groups. After 6 months, estradiol and biochemical markers of bone metabolism were at postmenopausal levels, with no difference between the groups. There was no difference in bone loss in the three groups, at all sites. Mean lumbar bone loss was 4.01 +/- 2.59% (mean +/- SD) in this population. In this study dosages of 100 IU and 200 IU daily of nasal sCT were insufficient to prevent bone loss during GnRH agonist treatment.

Bone loss in patients with inflammatory bowel disease: a prospective study

To assess the rate of bone loss in patients with inflammatory bowel disease, we prospectively studied 35 patients (17 women) aged 36 +/- 13 (range 17-60) years, 14 of whom had Crohn's disease and 21 with ulcerative colitis (including 12 with ileoanal anastomosis). Bone mineral density was measured by dual-energy X-ray absorptiometry at the lumbar spine and femoral neck. The follow-up was 19 +/- 8 months. During this period, 14 patients received oral steroids. Lumbar bone density changes expressed as a percentage per year were -3.1 +/- 4.9%, -6.4 +/- 7.5% and +2.0 +/- 4.0% in Crohn's disease and ulcerative colitis without and with ileoanal anastomosis respectively (p = 0.007). The same pattern was observed at the femoral neck. Mean annual lumbar bone density changes were -6.2 +/- 7.0% and +0.9 +/- 3.9% in patients with and without steroids during follow-up (p = 0.002). We conclude that patients with inflammatory bowel disease are at risk of lumbar and femoral bone loss. However, bone loss is not observed in patients with ileoanal anastomosis.

Adult-onset idiopathic phosphate diabetes. II. Time-course of clinical, laboratory test, and bone mineral density abnormalities under combined phosphate and calcitriol therapy

STUDY OBJECTIVE

to investigate the time-course of clinical, laboratory test, and bone mineral density abnormalities in patients with mild phosphate diabetes treated for at least one year with calcitriol, 0.5 to 1.5 micrograms, and oral phosphate, 788 to 2300 mg per day, in three divided doses.

PATIENTS AND METHODS

we studied eight patients with mild phosphate diabetes defined as a rate for tubular reabsorption of phosphate of less than 18% with a maximal rate for tubular reabsorption of phosphate (Tm) of less than 0.77 in the absence of any detectable cause of secondary tubular disease. Treatment efficacy was evaluated on the basis of pain severity, pain-related functional disability, serum phosphate and calcium levels, maximal rate for tubular reabsorption of phosphate, and dual-photon absorptiometry-measured bone mineral density.

RESULTS

three patients experienced complete relief of pain and fatigue and were able to resume their normal activities. Partial relief was seen in two other patients. The three remaining patients had no response to treatment. Renal colic occurred in one patient. None of the patients developed hypercalcemia.

Adult-onset idiopathic phosphate diabetes. I. Chronic pseudoinflammatory back pain and osteopenia

STUDY OBJECTIVE

to investigate clinical, laboratory test, and bone mineral density abnormalities in 19 adults with phosphate diabetes of unknown etiology diagnosed in a rheumatology department on the basis of a maximal rate for tubular reabsorption of phosphate (TmPO4/GFR) of 0.77 or less.

RESULTS

there were 14 males and five females with a mean age of 36.7 years (range 20 to 68 years) at symptom onset and 43.9 years (24-70) at diagnosis. Seventeen patients (90%) had back pain and 13 (68%) had nerve root pain. The pain was nocturnal only or both nocturnal and diurnal in 14 cases (74%). Other manifestations were fatigue (n = 7, 37%), myalgia (n = 6, 32%), fracture (n = 6, 32%), renal colic (n = 4, 21%), and pseudodepression (n = 10, 53%). Laboratory test abnormalities were as follows: serum phosphate, 0.72 mmol/L (0.58-0.89); rate for tubular reabsorption of phosphate, 74% (54-84%); maximal rate for tubular reabsorption of phosphate, 0.58 (0.4-0.76); urinary calcium/urinary creatinine > 0.48 in nine patients (47%); and fractional potassium excretion > 20% in seven patients (37%). Normal values were found for serum levels of Ca++, Na++, Mg++, creatinine, cortisol, T3, T4, TSH, 25(OH)D3, and 1,25(OH)2 D3. Tests for glycosuria and amino aciduria were negative. Bone mineral density measurements showed z-scores of -2.13 (+0.9 to -4.25) at L2-L4, and -1.34 (+1.5 to -3.2) at the femoral neck. Bone histology showed osteoporosis with a mild increase in osteoid deposition.

CONCLUSIONS

idiopathic adult-onset phosphate diabetes manifests as chronic back pain and nerve root pain, sometimes with fatigue and depression. Bone mineral density values are decreased and histology shows osteopenia. Differential diagnoses include spondyloarthropathy, disk disease, fibromyalgia, and depression. Determination of the maximal rate for tubular reabsorption of phosphate is the only means of establishing the diagnosis.

Sensitivity to change of various roentgenological severity scoring systems for osteoarthritis of the hip

RATIONALE

joint space assessment on roentgenograms is considered reliable for evaluating the anatomic severity of hip osteoarthritis. Methods for measuring this parameter include the scoring system developed by Kellgren and Lawrence, joint space width measurement, and joint space surface area measurement after digitalization of roentgenograms.

OBJECTIVE

to compare the sensitivity to change of the three above-listed methods.

PATIENTS AND METHODS

the study included patients with hip osteoarthritis meeting ACR criteria for whom two roentgenograms showing evidence of hip osteoarthritis taken 10 to 15 months apart were available. Roentgenograms were read by a single investigator who was unaware of the chronological order of films. Sensitivity to change of the three measurement techniques was determined by calculating standardized response mean (mean change/standard deviation of change).

RESULTS

the study evaluated 34 hips (68 roentgenograms) in 22 patients (12 females and ten males, mean age 63 +/- 10 years) with osteoarthritis of one (n = 10) or both (n = 12) hips. Standardized response mean were 0.37, 0.33, and 0.16 for joint space width, joint space surface area, and the Kellgren-Lawrence score, respectively.

CONCLUSION

this study suggests that joint space width or surface area may be more sensitive than the Kellgren-Lawrence score for monitoring the course of hip osteoarthritis.

Management of refractory ankylosing spondylitis and related spondyloarthropathies

Ankylosing spondylitis is the prototype of an interrelated group of disorders termed spondyloarthropathies, which include reactive arthritis, psoriatic arthritis, and rheumatic disorders associated with inflammatory bowel disease. It can be difficult to differentiate between these disorders because they may occur simultaneously or sequentially. In addition, some of the clinical characteristics of these diseases, such as enthesiopathy and eye involvement, are similar no matter what the diagnosis. The monitoring, diagnosis, and treatment of these diseases are related more to their clinical presentation than to the precise diagnosis.

Effect of cyclosporin A on interleukin-6 and soluble interleukin-2 receptor in patients with rheumatoid arthritis

OBJECTIVE

To investigate the effect of cyclosporin A (CyA) therapy on circulating concentrations of interleukin-6 (IL-6) and soluble interleukin-2 receptor (sIL-2R) in patients with rheumatoid arthritis (RA).

METHODS

Twenty four RA patients with active disease were studied. Plasma was collected before and after 16 weeks of CyA treatment. IL-6 was measured by B9 bioassay and sIL-2R by enzyme linked immunosorbent assay (ELISA).

RESULTS

The initial median IL-6 concentration of 165 IU/ml decreased significantly to 71 IU/ml after 16 weeks (p < 0.05). Similarly, the initial median plasma sIL-2R value of 665 U/ml decreased significantly to 570 U/ml (p < 0.05). This decrease was accompanied by an improvement in clinical parameters of disease activity. Some association between sIL-2R, IL-6, haemoglobin, and platelets was also observed.

CONCLUSIONS

This study has demonstrated that, in vivo, CyA therapy in RA can significantly reduce circulating concentrations of IL-6 and sIL-2R. Modulation of both T and non-T cell derived cytokines may be one mechanism by which CyA improves rheumatoid disease. Whether this is a direct effect of CyA on the cells within the rheumatoid joint producing these cytokines or an indirect effect mediated by other cytokines which can influence IL-6 and Il-2R values remains to be determined.

Metabolic bone assessment in patients with inflammatory bowel disease

BACKGROUND/AIMS

Patients with inflammatory bowel disease are at risk for osteopenia. To study the metabolic bone status of these patients, a cross-sectional study was conducted.

METHODS

Eighty-four patients (49 women, 35 men) with inflammatory bowel disease, 34 of whom had Crohn's disease and 50 ulcerative colitis (including 18 with prior coloproctectomy and ileoanal anastomosis), underwent clinical, dietary, and spine radiological assessments. Bone metabolism was assessed by measuring serum levels of calcium, phosphate, parathyroid hormone (1-84), 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and osteocalcin. Lumbar and femoral neck bone mineral densities were measured by dual energy X-ray absorptiometry.

RESULTS

Serum osteocalcin level was decreased in 29 patients (34%), 12 of whom had never undergone steroid therapy. The other biochemical markers of bone metabolism were in the normal range. Thirty-six patients (43%) had osteopenia, and 6 patients (7%) had vertebral crush fractures. Osteopenia was observed in 27 patients (52%) and 9 patients (28%) with and without corticosteroid therapy, respectively. No patient had clinical or biological signs of osteomalacia. Analysis of bone density (lumbar Z score) by a multiple regression analysis showed a statistically significant correlation with age, cumulative corticosteroid doses, sedimentation rate, and osteocalcin level (R2 = 0.76; P = 0.05).

CONCLUSIONS

The results suggest that bone turnover in inflammatory bowel disease is characterized by low bone formation in the presence of normal levels of calcium-regulating hormones.

Are classification criteria for spondylarthropathy useful as diagnostic criteria?

The authors used data from a study conducted under the auspices of the Société Française de Rhumatologie to evaluate the sensitivity and specificity of the individual items of two sets of criteria for spondylarthropathy. The study included 124 patients with spondylarthropathy and 1,964 controls. They found that the spondylarthropathy criteria with the highest sensitivities and specificities were useful not only for classifying patients but also for assisting in the diagnosis of spondylarthropathy.

[Chondroscopy: a new method for measuring osteoarthritis?]

Arthroscopy allows direct visual examination of joint cavity components and is useful for the diagnosis, treatment and evaluation of lesions. We investigated the contribution of arthroscopy to the evaluation of joint cartilage. The severity of cartilage lesions can be assessed using a total 100-mm visual analog scale (0 = no chondropathy; 100 = the worst possible lesions) or a more objective system based on the site, depth, and surface area of the lesions. This latter system was developed by the French Society for Arthroscopy (Société Française d'Arthroscopie) and provides a score and a class (SFA score and SFA grade). We investigated whether this system has the characteristics required of an evaluation tool, i.e., simplicity, reproducibility, clinical relevance, sensitivity to change, and discriminant capacity. Arthroscopy is an invasive procedure. However, we introduced several simplifications, including use of local rather than general anesthesia, performance on an outpatient basis, elimination of the tourniquet (to avoid muscular dysfunction), and use of a small arthroscope. This simplified technique is called chondroscopy. Intra-observer reproducibility is far better than inter-observer reproducibility. We found a good correlation between the two arthroscopy scales (visual analog scale and SFA scale). Chondroscopy and roentgenographic evaluations of cartilage lesions were closely correlated. Changes in the severity of cartilage lesions were correlated with changes in functional impairment. Chondroscopy proved capable of demonstrating statistically significant changes in cartilage lesions due to knee osteoarthritis between two evaluations done only one year apart, even in a small sample of patients (less than 20). A preliminary study of repeated hyaluronic acid injections suggested that chondroscopy may be capable of identifying truly chondromodulating agents.

Predictive factors for the longterm outcome of spondyloarthropathies

OBJECTIVE

To determine the predictive factors of outcome in patients with spondyloarthropathy (European Spondyloarthropathy Study Group or Amor criteria) monitored by a single investigator.

METHODS

Classification of longterm outcome on a 3-grade scale. Candidate predictive factors: presence or not of 12 clinical or biological variables during the first 2 years of the disease, collected by history at the time of the first visit. Univariate analysis to pick up the factors statistically correlated with severity and then odds ratio and 95% confidence interval (CI) for each variable were calculated.

RESULTS

Of the 328 patients with spondyloarthropathy, 151 had a followup of > or = 10 years and minor disease (81), severe (28), or moderate disease (42). Seven variables at entry were correlated with disease severity (odds ratio; CI 95%); hip arthritis (22.85; 4.43-118); erythrocyte sedimentation rate > 30 mm/h (7; 4.84-9.50); poor efficacy of nonsteroidal antiinflammatory drugs (8.33; 2.56-27.10); limitation of lumbar spine (7; 2-25); sausage-like finger or toe (8.45; 1.48-9); oligoarthritis (4.25; 1.38-13.10); onset < or = 16 years (3.47; 1.06-12.75). If none of these factors is present at entry a mild outcome can be predicted (sensitivity: 92.5%; specificity: 78%). If a hip is involved or if 3 factors are present, a severe outcome is predictable (sensitivity: 50%) and a mild disease practically excluded (specificity: 97.5%).

CONCLUSION

Predictive factors of poor or benign longterm outcome could be defined very early after onset of spondyloarthropathy in a set of patients monitored by one observer.

A possible linkage of HLA-DRB haplotypes with Tiopronin intolerance in rheumatoid arthritis

To investigate the relationship between HLA class II genotypes and toxic intolerance during treatment with Tiopronin, a slow-acting drug used in the treatment of rheumatoid arthritis (RA), we studied 40 patients who were divided into two groups: a group of 22 patients without side effects and a group of 18 patients with intolerance to Tiopronin. The PCR-RFLP method was used to determine the HLA-DR, DQ and DP genotypes. The patients in the two groups had similar genetic backgrounds with an expected high frequency of DRI and DR4 alleles. However, DR1/DR4 heterozygosity was significantly increased in patients with intolerance (p = 0.03, Odds Ratio = 10.5). In addition, one intolerant patient had a DR1/DR7 genotype which shared DRw53 (DRB4*0101) with DR1/DR4. Furthermore, two subtypes of DR5, DRB1*1102 and DRB1*1201, were increased among intolerant patients (11.1% vs 0%, p = 0.03, OR = 13.97). In total, DR1/DRw53 heterozygotes, DRB1*1102 and DRB1*1201 represented 61.1% of intolerant patients. Therefore, a detailed HLA class II typing might be useful before RA treatment by Tiopronin to predict and avoid toxic side effects in the patients with increased risk. Further investigation is currently underway.

Efficacy and tolerability of a new formulation of oral tiludronate (tablet) in the treatment of Paget's disease of bone

We sought to assess efficacy and safety of a new oral formulation (tablet) of tiludronate in Paget's disease of bone. We studied 128 patients with Paget's disease in an open-label uncontrolled trial. Patients received a daily dose of 400 mg oral tiludronate (two tablets). Treatment was for 6 months. Serum alkaline phosphatase activity (SAP) and fasting urinary excretion of hydroxyproline/creatine (OH/Cr) were measured every 3 months, as were biochemical parameters reflecting renal, hepatic, and hematologic functions. Analgesic efficacy was self-evaluated from a visual analog scale (VAS). Statistical analysis revealed a significant reduction from baseline in SAP and OH/Cr levels, as well as VAS scores. In the whole population with evaluation under treatment, there was a reduction in initial SAP activity after 3 months (47.2 +/- 2.2%, mean +/- SEM) and 6 months (58.3 +/- 2.3%). In the population with SAP levels above twice the upper limit at inclusion and with evaluation at month 3 and month 6 (n = 96), the reduction in SAP levels was 49.3 +/- 2.4% after 3 months and of 59.5 +/- 2.6% after 6 months (ANOVA time effect, p = 0.0001). Aside from mild gastrointestinal disturbances, as experienced with other oral bisphosphonates, clinical tolerance was good. Exhaustive biochemical investigation failed to reveal significant toxicity of tiludronate tablets at the dose of 400 mg/day. The dose of 400 mg daily of this new formulation appears to be a satisfactory tiludronate regimen for the treatment of Paget's disease of bone.

[Cost of intensive treatment followed by autograft of circulating stem cells. Application to multiple myeloma]

OBJECTIVES

Legitimate efforts to reduce health care costs, especially of intensive protocols including transplantation for haematological diseases, require realistic economic evaluations. We determined the direct cost of intensive chemotherapy associated with total body irradiation and autologous blood stem cell transplantation in patients with multiple myeloma.

METHODS

Ten consecutive patients (7 males, 3 females) with Stage II or II multiple myeloma, who had received no prior treatment and were under the age of 55, were included in the study. Peripheral blood stem cells were collected by successive cytaphereses after a short period of aplasia induced by a CHOP protocol. During this period, the patients were in normal hospital rooms. A VAMP protocol was then administered in three 4-day sessions. Intensive therapy was started 1 month later with CCNU, etoposide, cyclophosphamide and melphalan. Total body irradiation (12 Gy) was performed on days -3, -2, -1. Autologous grafting was done on day 0. The intensive therapy was followed by a period of aplasia and the patients were protected in laminar flow rooms. Regular antibiotic and haematologic protocols were applied. Growth hormone was not given. The patients were seen regularly for follow-up and interferon alpha 2b was prescribed for 5.

RESULTS

The mean cost of the two year treatment was 468,392 +/- 167,467 French francs. Personnel accounted for 36% of the total cost, marrow collection 13%, blood products 9.8%, laboratory tests 8.2% and drugs 7.2%. Little data are available in the literature of comparable cost analyses in other French hospitals or in other countries.

CONCLUSION

Controlled cost/benefit studies should be conducted to enable a rigorous comparison between different therapeutic strategies.