Severe hypovitaminosis D correlates with increased inflammatory markers in HIV infected patients

BACKGROUND

Even though it has been suggested that antiretroviral therapy has an impact on severe hypovitaminosis D (SHD) in HIV infected patients, it could be speculated that the different levels of residual inflammation on HAART (Highly Active Anti Retroviral Therapy) could contribute to SHD and aggravate bone catabolism in these patients.

METHODS

A cross-sectional study was carried out in an unselected cohort of 263 HIV infected outpatients consulting during Spring 2010. Clinical examinations were performed and medical history, food habits, sun exposure and addictions were collected. Fasting blood samples were taken for immunological, virological, inflammation, endocrine and bone markers evaluations.

RESULTS

Ninety-five (36%) patients had SHD. In univariate analysis, a significant and positive association was found between SHD and IL6 (p = 0.001), hsCRP (p = 0.04), increased serum C-Telopeptides X (CTX) (p = 0.005) and Parathyroid Hormon (PTH) (p < 0.0001) levels. In multivariate analysis, SHD deficiency correlated significantly with increased IL-6, high serum CTX levels, lower mean daily exposure to the sun, current or past smoking, hepatitis C, and functional status (falls), but not with the time spent on the current HAART (by specific drug or overall).

CONCLUSIONS

SHD is frequent and correlates with inflammation in HIV infected patients. Since SHD is also associated with falls and increased bone catabolism, it may be of interest to take into account not only the type of antiretroviral therapy but also the residual inflammation on HAART in order to assess functional and bone risks. This finding also suggests that vitamin D supplementation may be beneficial in these HIV-infected patients.

Brief report: inhibition of interleukin-6 function corrects Th17/Treg cell imbalance in patients with rheumatoid arthritis

OBJECTIVE

From an immunologic standpoint, the mechanisms by which treatment with tocilizumab (TCZ), a humanized anti-interleukin-6 (anti-IL-6) receptor antibody, results in improvement in rheumatoid arthritis (RA) patients are still not fully understood. In vitro studies and studies in mouse models have demonstrated the critical role of IL-6 in Th17 cell differentiation. Th17 lymphocytes have been shown to be strongly involved in RA pathogenesis, and the purpose of this study was to investigate the effect of IL-6 blockade on the balance between Th17 cells and Treg cells in patients with active RA.

METHODS

Patients with active RA for whom TCZ had been prescribed by a rheumatologist were enrolled in this study. Phenotypic analyses of T cell populations were performed, and the Disease Activity Score in 28 joints (DAS28) was assessed. Serum cytokine levels and other parameters of inflammation were measured before the first infusion and after the third infusion of TCZ (8 mg/kg).

RESULTS

Compared to controls, levels of Th17 cells (CD4+IL-17+) were increased and Treg cells (CD4+CD25(high) FoxP3+) were decreased in the peripheral blood of patients with active RA. The suppressive function of circulating Treg cells was not impaired in patients with active RA. TCZ treatment induced a significant decrease in the DAS28 associated with a significant decrease in the percentage of Th17 cells (from a median of 0.9% to 0.45%; P = 0.009) and an increase in the percentage of Treg cells (from a median of 3.05% to 3.94%; P = 0.0039) in all patients.

CONCLUSION

This study demonstrates for the first time that inhibition of IL-6 function by TCZ corrects the imbalance between Th17 cells and Treg cells in patients with RA.

Clinical interest of bone marrow aspiration in rheumatology: a practice-based observational study of 257 bone marrow aspirations

Bone marrow aspiration (BMA) can be performed by rheumatologists for diagnostic purposes in clinical practice. The aim of the study was to assess professional practices of hospital-based rheumatologists with regard to BMA in order to identify the relevant indications. A retrospective observational study in patients hospitalised in a French university hospital was conducted between 2005 and 2011. All of the patients who had a BMA in the rheumatology department during the study period were included. Clinical indication, number and results of BMA and of bone marrow biopsy (BMB) were collected. Stage and treatment of the haematological disease implemented following the BMA were described. Two hundred fifty-seven BMAs and 79 BMBs were performed during the study period. Of the BMAs, 14.1 % were pathological: myeloma (n = 12), malignant B cell non-Hodgkin's lymphoma (n = 6), myelodysplastic syndrome (n = 6), chronic lymphoid leukaemia (n = 4), Waldenstrom's disease (n = 3), chronic myelomonocytic leukaemia (n = 2), hairy cell leukaemia (n = 1) and acute lymphoblastic leukaemia (n = 1). Eight of the 14 pathological BMBs were associated with normal BMA. BMAs were performed equally for gammaglobulin abnormalities (monoclonal peak = 45 % of indications, hypogammaglobulinemia = 6 %) and for other reasons (haemogram abnormality = 24 %, skeletal osteolysis = 6 %, unexplained inflammatory syndrome = 5 %, lymph node disease = 4 % and others). In clinical rheumatology, BMA may reveal two major types of malignant haematological diseases: myeloma with poor prognostic factors justifying polychemotherapy and autologous grafts and, in contrast, slowly evolving B cell lymphoid haemopathies. Given the additional risk in some types of chronic inflammatory rheumatism, BMB should be performed more frequently in certain specific situations (skeletal or lymph node tumour and unexplained inflammatory syndrome).

Three-dimensional kinematics of the lower limbs in hip osteoarthritis during walking

OBJECTIVE

To describe the kinematic adaptations of all lower limb joints in hip osteoarthritis patients during walking.

METHODS

Patients with unilateral primary hip OA, without associated joint disorders were included. Normal subjects were included as controls. Gait analysis, using a 3-dimensional computerised gait analysis system was used to evaluate the usual spatiotemporal parameters, the peak motion of the hips, knees, and ankles during walking, and the intersegmental coordination of the lower limbs.

RESULTS

Eleven patients, mean age =60.5 ± 7 years and nine controls, mean age=60.3 ± 7 years, were included. The gait of hip OA patients was characterised as follows: a reduced stride length, a reduced maximal flexion and extension in the OA hip, a reduced maximal contralateral hip range of motion, an increased ipsi- and contralateral ankle dorsal flexion, a decreased ipsilateral relative temporal phase between the thighs and shanks segments and an increased ipsilateral relative phase between the shanks and foot segments.

CONCLUSION

The present results suggest that hip OA patients use shorter stride length, less contra lateral and especially ipsilateral hip motion, modify ankles motion, and have a different intra-limb coordination pattern compared to control subjects.

Usefulness of routine hepatitis C and hepatitis B serology in the diagnosis of recent-onset arthritis. Systematic prospective screening in all patients seen by the rheumatologists of a defined area--brief report

OBJECTIVE

Previous studies evaluating the usefulness of systematic screening for hepatitis B and C in patients with recent-onset arthritis suffered from a major bias since they were conducted in hospitals. The objective of the present study was to evaluate the relevance of such screening, performed by hospital and office-based rheumatologists of a defined area, in the diagnosis of arthritis or inflammatory polyarthralgia of less than 1 year duration.

METHODS

The CRRRI is a network which includes most hospital and office-based rheumatologists of an area with a population of 506,755 inhabitants. All patients seen by the CRRRI participants in their usual practice between March 2008 and December 2010 for inflammatory polyarthralgia, mono-, oligo-, or polyarthritis of less than 1 year duration were included. Patients' serum samples were screened for the presence of anti-hepatitis C virus (HCV) antibodies, with positive samples further evaluated for HCV-RNA with a reverse transcriptase-polymerase chain reaction, and for the presence of hepatitis B virus (HBV) infection.

RESULTS

Two hundred and thirty-three patients were included (162 women, 71 men; mean age of 50.6±15.8 years). Patients were evaluated for inflammatory polyarthralgia (n=51), monoarthritis (n=21), oligoarthritis (n=35) or polyarthritis (n=126) lasting for a mean 19.8±29.8 weeks. No new HCV or HBV infection diagnosis was done.

CONCLUSION

In this study not suffering from a hospital-selection bias, screening for hepatitis C and B infection was not helpful in the diagnosis process of recent-onset arthritis.

KEY MESSAGES

Systematic hepatitis B and C serology is not relevant in patients with recent-onset (<1 year) arthritis.

Validation of a numerical rating scale to assess functional impairment in hip and knee osteoarthritis: comparison with the WOMAC function scale

OBJECTIVES

(1) To investigate the psychometric properties of a patient-reported numerical rating scale (NRS) for evaluating functional disability in osteoarthritis (OA), in comparison with the WOMAC function scale and with a physician-reported function NRS; (2) to estimate the patient acceptable symptomatic state (PASS) and the minimal clinically important improvement (MCII) values for treatment with non-steroidal anti-inflammatory drugs (NSAIDs).

METHODS

Data were extracted from a prospective multicentre study involving 1186 patients with knee or hip OA. The psychometric properties assessed were feasibility: percentage of responses, floor and ceiling effects; construct validity by examining the correlations with classically used OA outcomes measures; responsiveness by comparing the results of before and 1 month after treatment with NSAIDs using standardised response mean (SRM) and effect size (ES). The MCII and PASS values of each function scale were calculated by an anchoring method.

RESULTS

No floor or ceiling effect was observed. High correlations were observed as expected between the patient NRS and WOMAC function, pain visual analogue scale and patient global assessment. The responsiveness was moderate to large, with SRM and ES ranging from 0.6 (hip OA) to 0.9 (knee OA) and higher than that of the WOMAC function scale. The PASS was close to 3 for the NRS scales. The MCII appears to be the change that makes the OA functional disability decrease from baseline to the PASS.

CONCLUSION

The patient-reported NRS demonstrated good psychometric properties, similar to the WOMAC function scale and can be regarded as a promising tool in therapeutic evaluation and decision-making in OA.

Influence of the experience of the reader on reliability of joint space width measurement. A cross-sectional multiple reading study in hip osteoarthritis

OBJECTIVES

The objectives were to evaluate improvement in reliability of joint space width (JSW) measurements, according to the previous experience of the readers in hip osteoarthritis (OA).

METHODS

Fifty radiographs in hip OA patients from a randomized controlled trial (ECHODIAH) were read 12 times by two readers with different levels of experience in radiographic interpretation. Intra-reader reliability and inter-reader reliability were assessed through calculation of the smallest detectable difference (SDD) and the intra-class correlation coefficient (ICC).

RESULTS

Intra-reader reliability: for the experienced reader, no significant change in SDD was observed with repeated JSW measurements. For the junior reader, the SDD decreased significantly from 0.90 mm to 0.65 mm (P=0.002). A plateau of SDD was reached after reading 200 to 300 radiographs, with a value close to the mean SDD of the experienced reader (0.67 mm). ICCs were high (>0.88) for both the senior and the junior readers. Inter-reader reliability: no improvement in inter-reader reliability was noted with repeated measurements of JSW (SDD=0.81 mm). However, no additional training sessions were performed. ICCs were high (>0.85).

CONCLUSION

This study indicated for the first time a learning curve in analyzing JSW in hip OA for an inexperienced reader. After analyzing 200 to 300 radiographs, the junior reader reached an intra-reader reliability similar to the experienced reader. Moreover, the information brought by the ICC was not sufficient, suggesting that the SDD should be systematically reported in studies evaluating OA radiographic progression, on top of the ICC, to help in interpreting the JSW reliability.

Cross-cultural adaptation and validation of the French version of the Rheumatoid and Arthritis Outcome Score (RAOS)

OBJECTIVES

The Rheumatoid and Arthritis Outcome Score (RAOS) was recently developed to evaluate functional disability and quality of life in rheumatoid arthritis (RA) patients suffering from lower limb symptoms. The aims of this study were to cross-culturally adapt the RAOS into French and to assess its psychometric properties, in particular, responsiveness following intra-articular therapy.

METHODS

The French RAOS was developed according to cross-cultural guidelines and was then evaluated in symptomatic RA patients with lower limb joint involvement. The psychometric properties assessed were - feasibility: percentage of missing data and floor and ceiling effects; reliability: intra-class correlation coefficients (ICC, and Bland and Altman representation; internal consistency: Cronbach's alpha; construct validity by correlation with the SF-36 and HAQ (Spearman's rank test); responsiveness to intra-articular corticosteroid injection (hip, knee, hindfoot) using standardised response mean (SRM) and effect size.

RESULTS

Sixty patients were included (mean age 50.1±10.5 years). Neither floor nor ceiling effects were observed. Reliability was good with ICC for different RAOS subscales ranging from 0.76 to 0.91. Results for internal consistency (Cronbach's alpha ranging from 0.73 to 0.91) and construct validity were good. The responsiveness was moderate to large with SRMs ranging from 0.75 to 0.87 and effect sizes from 0.77 to 1.75 at two weeks following intra-articular corticosteroid injection.

CONCLUSIONS

The French version of the RAOS demonstrated good psychometric properties to capture functional disability and quality of life in RA. Moreover, the results suggest that the RAOS could be used as an outcome in trials evaluating single joint intra-articular injections.

Aspartame-induced fibromyalgia, an unusual but curable cause of chronic pain

We report for the first time an unusual musculoskeletal adverse effect of aspartame in two patients. A 50-year-old woman had been suffering from widespread pain and fatigue for more than 10 years leading to the diagnosis of fibromyalgia. During a vacation in a foreign country, she did not suffer from painful symptoms since she had forgotten to take her aspartame. All of the symptoms reappeared in the days following her return when she reintroduced aspartame into her daily diet. Thus, aspartame was definitively excluded from her diet, resulting in a complete regression of the fibromyalgia symptoms. A 43-year-old man consulted for a 3-year history of bilateral forearm, wrist, and hand and cervical pain with various unsuccessful treatments. A detailed questioning allowed to find out that he had been taking aspartame for three years. The removal of aspartame was followed by a complete regression of pain, without recurrence. We believe that these patients' chronic pain was due to the ingestion of aspartame, a potent flavouring agent, widely used in food as a calorie-saver. The benefit/ risk ratio of considering the diagnosis of aspartame-induced chronic pain is obvious: the potential benefit is to cure a disabling chronic disease, to spare numerous laboratory and imaging investigations, and to avoid potentially harmful therapies; the potential risk is to temporarily change the patient's diet. Thus, practitioners should ask patients suffering from fibromyalgia about their intake of aspartame. In some cases, this simple question might lead to the resolution of a disabling chronic disease.

Gait analysis as a quantifiable outcome measure in hip or knee osteoarthritis: a systematic review

OBJECTIVES

Kinematic gait analysis consisting of measuring gait parameters (stride length, gait speed, dynamic joint angles) is a potential outcome measure in osteoarthritis (OA). The aim of this study was to evaluate its psychometric properties.

METHODS

A systematic literature search was performed in PUBMED and the Cochrane database until January 2008 by selecting manuscripts assessing any psychometric property of gait analysis in knee or hip OA. Were assessed feasibility (cost, time and access); reliability; discriminant capacity by differences between OA and non-OA patients; construct validity by correlation between gait analysis and OA symptoms: pain or functional disability (Lequesne/WOMAC); and responsiveness by improvement of gait analysis after treatment of OA using effect size.

RESULTS

Among the 252 articles identified, the final analysis included 30 reports (i.e., 781 knee OA patients and 343 hip OA patients). Gait analysis presents various feasibility issues and there was limited evidence regarding reliability (three studies, 67 patients). Discriminant capacity showed significant reduction of gait speed, stride length and knee flexion in OA patients compared to healthy subjects. Few data were available concerning construct validity (three studies, 79 patients). Responsiveness of gait speed was moderate to large with effect size ranging respectively from 0.33 to 0.89 for total knee replacement, and from 0.50 to 1.41 for total hip replacement.

CONCLUSION

Available data concerning validity and reliability of kinematic gait analysis are insufficient to date to consider kinematic parameters as valuable outcome measures in OA. Further studies evaluating a large number of patients are needed.

Cross-cultural adaptation and validation of the French version of the Hip disability and Osteoarthritis Outcome Score (HOOS) in hip osteoarthritis patients

OBJECTIVE

To translate and adapt the Hip disability and Osteoarthritis Outcome Score (HOOS) into French and to evaluate the psychometric properties of this new version, by testing feasibility, internal consistency, construct validity, reliability and responsiveness, in patients with hip osteoarthritis (OA).

METHODS

The French version of the HOOS was developed according to published international guidelines to ensure content validity. The new version was then evaluated in two symptomatic hip OA populations, one with no indication for joint replacement (medical group), and the other waiting for total hip replacement (THR) (surgery group). The psychometric properties assessed were feasibility: percentage of responses, floor and ceiling effects; internal consistency using Cronbach's alpha; construct validity by evaluating correlations with the Lequesne's index and the visual analogic scale (VAS) for pain (Pearson's correlation coefficient); reliability: intra-class correlation coefficient (ICC), Bland et Altman representation; responsiveness by comparing the results of before and 1 month after injection of hyaluronic acid (medical group) and by comparing the pre and 3 months post THR results (surgery group) by calculating standardized response mean (SRM) and effect size (ES).

RESULTS

A total of 88 patients were recruited; 58 in the medicine group (mean age=61.8+/-9 years, range 42-81, 70% women) and 30 in the surgery group (mean age=67.5+/-9 years, range 50-81, 68% women). The percentage of item responses was excellent (99%). Neither a floor nor a ceiling effect was observed, except for a ceiling effect (17.8% of patients with worst possible score) observed prior to surgery in the sport and recreation subscale. The internal consistency was good for four of the five HOOS subscales. As expected, the strongest correlations were observed between all HOOS subscales and Lequesne's index or VAS pain, indicating good construct validity. The reliability was good, with an ICC>0.8 for all subscales. The responsiveness was good for all domains 1 month after hyaluronic acid injection (ES ranging from 0.73 to 1.86 and SRM from 0.51 to 1.04) and high for all domains 3 months after THR (ES ranging from 1.47 to 2.08 and SRM ranging from 1.97 to 3.24).

CONCLUSION

The French version of HOOS demonstrated good psychometric properties and appears to be useful for the evaluation of patient-relevant outcome whatever the severity of hip OA. This study provides a basis for the use of this French version of the HOOS in future clinical trials.

Psychometric properties of the French translation of the reduced KOOS and HOOS (KOOS-PS and HOOS-PS)

OBJECTIVE

To evaluate the psychometric properties of the French KOOS physical function (KOOS-PS) and HOOS physical function (HOOS-PS), specifically its feasibility, reliability, construct validity, and responsiveness.

METHODS

Consecutive outpatients consulting for primary knee or hip osteoarthritis (OA) in a rheumatology department were included. During the initial assessment, patients were asked to complete the Knee injury and Osteoarthritis Outcome Score (KOOS) or Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaire and the OsteoArthritis Knee and Hip Quality Of Life questionnaire (OAKHQOL). The patients were given a second KOOS or HOOS questionnaire to complete and return by mail 2 weeks later. Feasibility was assessed by calculating the percentage of missing items and the floor and ceiling effects. Test-retest reliability was evaluated using the intra-class correlation coefficient (ICC). Convergent and divergent construct validity was determined by comparing the results of the KOOS-PS or HOOS-PS and OAKHQOL questionnaires using Spearman's rank test. Responsiveness was evaluated using data obtained in other hip or knee OA patients prior to and 1 month after intra-articular hyaluronic acid injection, using standardized response mean (SRM) and effect-size (ES).

RESULTS

Eighty-seven patients with knee OA and 50 hip OA patients were included. The KOOS-PS and HOOS-PS scores were obtained for all patients as there were no missing items. Neither a floor nor a ceiling effect was observed. The ICC of KOOS-PS and HOOS-PS was 0.861 (0.763-0.921) and 0.859 (0.725-0.929), respectively. A strong or moderate correlation was observed, as expected, between KOOS-PS, HOOS-PS, and the OAKHQOL physical activities, pain, and mental health domains. A weak correlation was observed, as expected, between KOOS-PS, HOOS-PS, and the other OAKHQOL domains, except for a moderate correlation between the KOOS-PS and social functioning. The responsiveness was demonstrated with SRM and ES of 0.80 and 0.51 (KOOS-PS), 1.10 and 0.62 (HOOS-PS), respectively.

CONCLUSION

The French versions of KOOS-PS and HOOS-PS are reliable, valid, and responsive questionnaires for capturing functional disability in people with knee and hip OA.

OARSI-OMERACT definition of relevant radiological progression in hip/knee osteoarthritis

BACKGROUND

Joint space width (JSW) evaluated in millimeters on plain X-rays is the currently optimal recognized technique to evaluate osteoarthritis (OA) structural progression. Data obtained can be presented at the group level (e.g., mean+/-standard deviation of the changes). Such presentation makes difficult the interpretation of the clinical relevance of the reported results. Therefore, a presentation at the individual level (e.g., % progressors) seems more attractive but requires to determining a cut-off. Several methodologies have been proposed to define cut-offs in JSW: arbitrary chosen cut-off, cut-off based on the validity to predict a relevant end-point such as the requirement of total articular replacement or cut-off based on the measurement error such as smallest detectable difference (SDD).

OBJECTIVES

The objective of this OARSI-OMERACT initiative was to define a cut-off evaluated in millimeters on plain X-rays above which a change in JSW could be considered as relevant in patients with hip and knee OA.

METHODS

The first step consisted in a systematic literature research performed using Medline database up to July 2007 to obtain all manuscripts published between 1990 and 2007 reporting a cut-off value in JSW evaluated in millimeters at either the knee or hip level. The second step consisted in a consensus based on the best knowledge of the 11 experts with the support of the available evidence.

RESULTS

Among the 506 articles selected by the search, 47 articles reported cut-off of JSW in millimeters. There was a broad heterogeneity in cut-off values, whatever the methodologies or the OA localization considered (e.g., from 0.12 to 0.84 mm and from 0.22 to 0.78 mm for Knee (seven studies) and hip (seven studies), respectively when considering the data obtained based on the reliability). Based on the data extracted in the literature, the expert committee proposed a definition of relevant change in JSW based on plain X-rays, on an absolute change of JSW in millimeters and on the measurement error e.g., calculation of the SDD using the Bland and Altman technique. The results of the analysis of JSW should be expressed in terms of a dichotomous variable (e.g., progressors yes/no): a patient with a change in JSW during the study over such SDD will fulfill the definition of "progressor". Moreover, the pilot study aimed at evaluating the measurement error should be designed to reflect the different characteristics of the primary study in which the analysis of the radiological findings will be based on (patient's characteristics, centers characteristics, readers).

CONCLUSION

This initiative based on both an Evidence Based Medicine (Systematic Literature Research) and Expert Opinion approach resulted in a proposal of definition of relevant radiological progression in OA to be used as end-point in clinical trials and also recommendations on the conduct of the reliability study allowing such definition.

Cross-cultural adaptation and validation of the French version of the Knee injury and Osteoarthritis Outcome Score (KOOS) in knee osteoarthritis patients

OBJECTIVE

To adapt the Knee injury and Osteoarthritis Outcome Score (KOOS) into French and to evaluate the psychometric properties of this new version.

METHODS

The French version of the KOOS was developed according to cross-cultural guidelines by using the "translation-back translation" method to ensure content validity. KOOS data were then obtained in patients with symptomatic knee osteoarthritis (OA). The translated questionnaire was evaluated in two knee OA population groups, one with no indication for joint replacement (medicine), and the other waiting for joint replacement (surgery). The psychometric properties evaluated were feasibility: percentage of responses, floor and ceiling effects; construct validity: internal consistency using Cronbach's alpha, correlations with osteoarthritis knee and hip quality of life domains using Spearman's rank test, and known group comparison between medicine and surgery groups; reliability: intra-class correlation coefficient (ICC), Bland and Altman representation; responsiveness using data obtained prior to and 3 months after surgery: standardized response mean (SRM), and effect size.

RESULTS

Thirty-seven patients were included in the medicine group (68% women, mean age=70+/-10 years) and 30 in the surgery group (73% women, mean age=71+/-10 years). The percentage of responses was excellent. Neither a floor nor a ceiling effect was observed, except for the sport and recreation subscale (20.6% of patients with the worst possible score in the medicine group, 40 and 0% in the surgery group prior to and after surgery, respectively). Results for internal consistency (Cronbach's alpha ranging from 0.76 to 0.93), and convergent and divergent construct validity were satisfactory. The patients waiting for knee surgery presented with significantly lower scores in all KOOS domains. The reproducibility of measurements of all KOOS subscales was good to excellent, with ICC ranging from 0.755 to 0.914. The responsiveness was high, with SRM ranging from 0.89 to 1.93, and effect size from 1.31 to 2.8.

CONCLUSION

The French version of KOOS is a valid, reliable, and responsive instrument to capture specific aspects of functional disability affecting quality of life of knee OA patients.

Pedicle stress fracture: an unusual complication of pycnodysostosis

Pycnodysostosis is a rare dysplasia characterised by high bone density and susceptibility to long bone fractures caused by cathepsin K deficiency. Spinal abnormalities have rarely been described in this uncommon inherited bone dysplasia. A 28-year-old female, with a past history of pycnodysostosis and spontaneous leg fractures was hospitalized for a 2-month history of spontaneous low back pain. Physical examination revealed the typical facial and hand features of pycnodysostosis and local lumbar stiffness. No abnormalities were found in laboratory tests, particularly with regard to bone turnover markers. Fracture of the left pedicle of the third lumbar vertebra was suspected on lumbar radiographs and later confirmed by a computed tomography (CT) scan. A dramatic improvement in symptoms was achieved, thanks to a course of injectable calcitonin therapy and rest. To our knowledge, it is the first-ever reported case of pedicle stress fracture in a patient with pycnodysostosis, suggesting that spontaneous fractures resulting from this bone dysplasia do not only affect diaphysis of brittle long bones but could also affect the lumbar spine. Furthermore, the present case confirms previous observations in such patients of frequent spondylolysis, which could lead to abnormal lumbar pedicle stress. The dramatic improvement achieved by calcitonin therapy might be related to osteoclastic dysfunction in pycnodysostosis caused by a deficiency of cathepsin K, a cystein protease involved in bone matrix remodelling.

[Hypercalcemia of double origin: association of multiple myeloma and ectopic parathyroidal adenoma]

INTRODUCTION

Multiple myeloma and primary hyperparathyroidism are two causes of hypercalcemia. This association has already been described to be not casual, despite their link is still unknown.

OBSERVATION

We describe a 68 years old woman, without notable background, was admitted for low back pain. Biology showed an IgG Kappa multiple myeloma (stade 3) and an hypercalcemia without renal failure. Hypercalcemia was difficult to control with bisphosphonate and calcitonin. At first, there was also an hypophosphoremia and a high parathormone level (287 pg/ml). Imaging showed spread myeloma impairment and a right paramediastinal tissular mass. Biopsy diagnosed an ectopic parathyroidal adenoma.

DISCUSSION

Multiple myeloma and primary hyperparathyroidism can be associated. They are often revealed by an hypercalcemia difficult to control or refractory to the treatment. Hypophosphoremia can suggest the diagnosis of hyperparathyroidism. Both this observation and litterature (about twenty case reports) suggest that this double diagnosis should be systematicly evoked and explored by an assay of parathormone and a seric proteins electrophoresis in all hypercalcemia.

CONCLUSION

Multiple myeloma and parathyroidal adenoma should be both explored in all hypercalcemia, because they can be associated.

[Anti TNF-alpha treatment of a refractory polymyositis]

INTRODUCTION

Anti TNF-alpha agents may represent a possibility of treatment in cases of refractory polymyositis.

CASE REPORT

We report a case of polymyositis refractory to corticosteroids and immunosuppressive agents in whom adjunction of infliximab led to a mild and transient improvement, and a secondary improvement after discontinuation of the treatment.

DISCUSSION

In the reported cases of polymyositis treated with infliximab or etanercept a short-term response was seen in 9 out of 11 cases. Adverse events of the treatment are mentioned, and should be taken into account in the decision of treatment.

Kinematic adaptation of locomotor pattern in rheumatoid arthritis patients with forefoot impairment

Rheumatoid arthritis (RA) is a leading cause of disability, which affects primarily the forefoot. Moreover, the forefoot is the final ground body interface for transmitting forces produced by the plantar flexors in order to move the body forward. Therefore, a dysfunction in patients with arthritis might induce important changes in gait, such as modifications in the coordination between legs to correct a reduced range of motion (ROM) and to produce smooth stride motions. First, we wanted to investigate the modifications of gait parameters in order to get a deeper understanding of the locomotor adaptation after a distal joint impairment. Second, we wanted to extract the mechanisms used to compensate for these impairments. In order to carry out this study, RA patients with forefoot impairment and healthy subjects were asked to walk along a straight line at two different velocities and were recorded by a motion analysis system. Patients were able to produce an efficient pattern despite a reduction of the ROM of the forefoot. At normal speed, the substantial modification of the locomotor pattern was linked to the adaptation of the lower-limb segment coordination and to the loss of ROM. Compensative mechanisms are the results of an efficient adaptation that offset the effect of the lesions. In contrast, at high speed, all of the kinematic modifications observed at natural speed vanished. It seems that pain and its associated sensory signals help to update the motor command and compel patients to adjust the descending command to the altered representation of distal mobility. Finally, the mechanical consequences of these changes are of particular interest since different levels of force exerted at the hip, knee and ankle might result in a supplementary structural alteration of these joints.