Lupus attributable to anti-TNF therapy and revealed by interstitial granulomatous dermatitis.

Interstitial granulomatous dermatitis belongs to the group of aseptic cutaneous granulomas. It is a histopathological entity encountered in various pathological situations, such as polyarthritis including rheumatoid arthritis, but also systemic lupus erythematosus. It may also occur after systemic administration of medication, thus representing a drug-induced, interstitial granulomatous outbreak. This has recently been described after anti-TNF therapy was taken. We are reporting the case of a patient treated using adalimumab for rheumatoid arthritis and having developed interstitial granulomatous dermatitis during treatment, which revealed lupus erythematosus attributable to the biotherapy. The clinical appearance of interstitial granulomatous dermatitis can vary, and the diagnosis is confirmed by anatomo-pathological examination. Drug-induced interstitial granulomatous outbreaks have specific histological criteria, and secondary cases involving anti-TNF medication have been described. Cases of lupus attributable to anti-TNF therapy have also been described, and they have specific biological characteristics. Like idiopathic lupus, they may be associated with interstitial granulomatous dermatitis, but the association of an anti-TNF-induced lupus and this type of granulomatous has not, to our knowledge, been described before. We are reporting one case, which emphasises the importance of carrying out a complete and systematic aetiological assessment for all cases of interstitial granulomatous dermatitis, including where there is systemic disease or following medical treatment, either of which may provide an evident cause for the granulomatosis. In particular, the outbreak of interstitial granulomatous dermatitis during anti-TNF treatment should lead to screening for a drug-induced lupus, which would require the patient to stop such treatment.

Fractal dimension of trabecular bone: comparison of three histomorphometric computed techniques for measuring the architectural two-dimensional complexity.

Trabecular bone has been reported as having two-dimensional (2-D) fractal characteristics at the histological level, a finding correlated with biomechanical properties. However, several fractal dimensions (D) are known and computational ways to obtain them vary considerably. This study compared three algorithms on the same series of bone biopsies, to obtain the Kolmogorov, Minkowski-Bouligand, and mass-radius fractal dimensions. The relationships with histomorphometric descriptors of the 2-D trabecular architecture were investigated. Bone biopsies were obtained from 148 osteoporotic male patients. Bone volume (BV/TV), trabecular characteristics (Tb.N, Tb.Sp, Tb.Th), strut analysis, star volumes (marrow spaces and trabeculae), inter-connectivity index, and Euler-Poincaré number were computed. The box-counting method was used to obtain the Kolmogorov dimension (D(k)), the dilatation method for the Minkowski-Bouligand dimension (D(MB)), and the sandbox for the mass-radius dimension (D(MR)) and lacunarity (L). Logarithmic relationships were observed between BV/TV and the fractal dimensions. The best correlation was obtained with D(MR) and the lowest with D(MB). Lacunarity was correlated with descriptors of the marrow cavities (ICI, star volume, Tb.Sp). Linear relationships were observed among the three fractal techniques which appeared highly correlated. A cluster analysis of all histomorphometric parameters provided a tree with three groups of descriptors: for trabeculae (Tb.Th, strut); for marrow cavities (Euler, ICI, Tb.Sp, star volume, L); and for the complexity of the network (Tb.N and the three D's). A sole fractal dimension cannot be used instead of the classic 2-D descriptors of architecture; D rather reflects the complexity of branching trabeculae. Computation time is also an important determinant when choosing one of these methods.

[Septic arthritis of a lumbar facet joint. A case report]. / Arthrite septique inter-apophysaire postérieure à l'étage lombaire.

Septic arthritis of the posterior lumbar joints is extremely rare in comparison with spondylodiscitis which is much more common. We report a case of an 86-year-old women with septic arthritis of the left L4-L5 lumbar facet joint associated with endocarditis. Arthritis diagnosis was made on CT scan and MRI, infection by Staphyloccocus aureus was proved by blood cultures. Heart growth was seen by echocardiography. Twenty-three cases were reported in the literature. Clinical and biological data failed to discriminate between facet joint septic arthritis and spondylodicitis. Diagnosis is established on imaging findings, computed tomography and magnetic resonance imaging, completed by blood cultures and, if they are negative, by aspiration-biopsy. Appropriate antimicrobial therapy is usually successful. Some back pain generally persists. In conclusion, lumbar pain with fever without spondylodiscitis is suggestive of septic arthritis of a lumbar facet joint. Epiduritis associated in 60% patients requires rapid treatment.

[Present status of Poncet's tuberculous rheumatism. A new case]. / Actualité du rhumatisme tuberculeux de Poncet. Une nouvelle observation.

A case of noninfectious polyarthritis of over one year's duration with calcaneal enthesopathy in a patient with visceral tuberculosis is reported. This pattern, termed Poncet's disease, shares pathophysiologic mechanisms with Freund's complete adjuvant-induced arthritis. Future studies should include polymerase chain reaction studies to look for the tubercle bacillus in joint fluid or synovial biopsy specimens.

[Magnetic resonance imaging of fluorosis and stress fractures due to fluoride]. / L'imagerie par résonance magnétique des fluoroses et fractures de contrainte dues au fluor.

Osteocondensation of the spine and stress fractures of the appendicular bones are observed under treatment with sodium fluoride or after long-term drinking of Vichy Saint-Yorre spring water. Five patients with a mean total dose of fluoride intake of 24.7 g (9-66) were studied with MR imaging. Two of them had a diffuse osteocondensation; MRI showed a low signal intensity in the vertebrae on T1 and T2-weighted images. MRI was performed in an asymptomatic patient who was being treated with sodium fluoride for 16 months; it revealed a heterogenous low signal intensity in the pelvis and femoral metaphysis. Two patients experienced stress fractures; MRI demonstrated a linear area of very low signal intensity surrounded by an area of decreased signal intensity on T1-weighted images and high signal intensity on T2-weighted images. MRI of fluorosis shows a non specific low signal intensity linked to a densifying image on the standard radiograph or an area of high technetium-99m intake on bone scan.

Rheumatological symptoms due to retinoids.

Isotretinoin and etretinate are synthetic derivatives of vitamin A widely used in the treatment of dermatological diseases, mainly those affecting keratinization. They have numerous side-effects, among which the rheumatic symptoms are not the most common or the most severe. The main skeletal adverse reaction of retinoids is hyperostosis. It mainly occurs with protracted treatments and high dosages, and its incidence may exceed 80% after a few years of administration. Hyperostosis is axial, located in the cervical and thoracic spine, and may be responsible for limitation of movement; in the appendicular bone, enthesopathies occur at the foot, pelvis, hip, and less commonly the shoulder and elbow. They are usually mild and asymptomatic. The radiological appearance is very similar to diffuse idiopathic skeletal hyperostosis. Isotretinoin tends to be responsible for axial involvement, etretinate for peripheral locations. The other skeletal side-effects are uncommon and include periosteal proliferation, calcification of the interosseous membrane of the forearm and diffuse radiological bone hyperlucency. In children, premature epiphyseal closure is very rare. About 20% of patients complain of musculoskeletal pain and arthralgias. A few cases of true arthritis have been reported. Retinoids may be responsible for muscular damage and an abnormality of muscular tone resembling the stiff-man syndrome. Some cases of necrotizing vasculitis and three cases of Wegener's granulomatosis have been observed in patients treated with retinoids. Except for these latter arguable cases, rheumatoid syndromes due to retinoids are rather benign, and should not be an obstacle to the future development of their therapeutic utilization.