Search

The aim of this study was to assess the prevalence of and diagnostic role of metacarpal osteopenia in rheumatoid arthritis (RA) and to evaluate its detectability using receiver operating characteristic (ROC) analysis. Metacarpal bone mineral density was measured in 98 patients with classical RA using a computer-assisted measure of 6 metacarpal diameters (radiogrammetry) in patients aged less than 50 years. Sensitivity and specificity of the technique in discriminating the RA patients from 85 normal controls and osteopenic RA subjects from their normopenic counterparts, was determined by standard statistical techniques. Clinical, laboratory and radiological variables were compared in their ability to explain the variance of metacarpal bone density. The prevalence of metacarpal osteopenia in RA was 55%. Prolonged disease and reduced function significantly differentiated osteopenic from non-osteopenic RA patients. Discriminant analysis of RA and control groups showed that measurement of 6 metacarpals was more accurate than the 2nd metacarpal measurement alone in predicting the RA patients. The sum of 6 metacarpal combined cortical width (CCW) had a sensitivity of 61% and specificity of 68% in discriminating the RA patients from the controls. Receiver operating characteristics curves showed, not surprisingly, that objective measurement of bone diameters was superior to clinical or laboratory measures of disease activity in correctly classifying a randomly chosen RA patient as osteopenic or not. Metacarpal osteopenia is common in RA and it may be a useful measure of the disease in young patients.

We report the prevalence of metacarpal cortical thinning in systemic lupus erythematosus (SLE). Fifty-eight ambulant female patients attending a lupus clinic (mean age 32.4 years), were found to have significant thinning of metacarpal cortices (p < 0.05) when compared with 63 normal females (mean age 34.1 years). However, metacarpal bone mass was within the normal range. Measurements were made at 6 metacarpals of the 2 hands using a computer-aided technique (digitized radiogrammetry). Femoral cortical width and Singh index at the left femur, as well as the vertebral index at L3 were also recorded. The trabecular indices were in the range of normality, but the SLE group had more patients in the immediately pre-osteopenic range. Metacarpal bone loss was not related to disease duration or corticosteroid therapy. The prevalence of osteopenia in SLE is probably underestimated and the pathogenesis is likely to be multifactorial.

The prevalence of keratoconjunctivitis sicca (KCS) was studied in a randomly selected group of 104 patients with rheumatoid arthritis (RA). Symptoms of KCS were noted in 33 patients (31.7%) and they were studied further. After rose bengal staining, 22 of these patients were found to have KCS which was diagnosed by the presence of corneal or conjunctival desiccation. The overall prevalence of KCS was 21.2%. Although an abnormal Schirmer's test was noted in 21 of the 22 patients with KCS, only 8 patients had values of 5 mm or less while the remainder had a mild abnormality ranging from 6 to 15 mm. A reduced marginal tear film was noted in 15 patients (68.2%) with KCS and 13 patients (59%) had a reduced tear break-up time. The Schirmer's test alone is inadequate to make a definite diagnosis of KCS and it is essential to perform slit lamp examination to detect epithelial staining with rose bengal.