Generalized osteoarthritis in women: pattern of joint involvement and approaches to definition for epidemiological studies

OBJECTIVE

To ascertain whether clustering between joint sites in osteoarthritis (OA) is more common than would be expected simply from the rising prevalence of the disorder with age, and to explore a definition of generalized OA (GOA) by determining the pattern of joint group involvement, in a population sample of peri and postmenopausal women.

METHODS

Radiographs of the hands, knees, and hips were obtained in a population sample of 702 women aged 45 to 64 years. Distal interphalangeal, proximal interphalangeal, carpometacarpal, knee, and hip OA were assessed using the Kellgren-Lawrence grading system. Logistic regression was used to test for overall clustering of OA between joint sites, and log linear models were used to study the patterns of association between different sites.

RESULTS

Multiple involvement of the 5 joint groups studied occurred significantly more frequently than could be expected by chance alone (chi 2 = 52.3, df = 5, p < 0.001), and this clustering remained significant after age adjustment (chi 2 = 26.1, df = 5, p < 0.001). Thresholds could be defined for the number of involved joint groups that distinguished a polyarticular subset of OA. These thresholds varied with age and the radiographic cutoff at which OA was assigned. Thus, for grade 2+ disease, GOA could be defined by involvement of 2 or more joint groups at age 45-47 years, but required involvement of all 5 joint groups at age 60-64 years. Symmetry within joint groups was the most pronounced feature in the pattern of joint involvement in the sample as a whole, with associations between different joint groups being substantially weaker than those for symmetrical bilateral involvement of a particular joint.

CONCLUSION

There is a clear tendency towards polyarticular OA among women aged 45-64 years. However, there is no single threshold number of joint sites that can be used to define GOA. The pattern of joint involvement in OA is primarily symmetrical, and this pattern strongly suggests a systemic etiology in this subset of postmenopausal women.

Biochemical characterization of the reverse transcriptase of a human intracisternal A-type particle (HIAP)

The discovery of novel human intracisternal A-type particle (HIAP) that may be associated with the autoimmune disease Sjŏgren's syndrome has been previously reported. Although the HIAP retrovirus has been shown to be antigenically related to HIV-1, the viruses were distinguishable by different hydrodynamic mobilities through a sucrose gradient by morphology and intracellular location, and by differing divalent cation requirements for their in vitro reverse transcriptase (RT) reactions. In this report, additional biochemical characteristics are provide that further differentiate the HIAP RT from HIV-1 RT. Data are also presented that distinguish the HIAP RT from the known cellular DNA polymerases.

The effect of weight-bearing exercise on bone mineral density: a study of female ex-elite athletes and the general population

The aim of this retrospective cohort study was to estimate the changes in bone mineral density (BMD) as a consequence of exercise in female ex-athletes and age-matched controls. Eighty-three ex-elite female athletes (67 middle and long distance runners, 16 tennis players, currently aged 40-65) were recruited from the original records of their sporting associations. Controls were 585 age-matched females. The main outcome measures were BMD of lumbar spine (LS), femoral neck (FN), and forearm, estimated by dual-energy X-ray absorptiometry (DXA) scan. Levels of physical activity were assessed using a modified Allied Dunbar Fitness Survey scale and classified as (a) ex-athletes, (b) active controls (> or = 1 h of vigorous physical activity currently and in the past), (c) low activity controls with inconsistent or intermediate levels of activity, and (d) inactive controls (< 15 minutes of exercise per week). After adjustment for differences in age, weight, height, and smoking, athletes had greater BMDs than controls: 8.7% at the LS (95% confidence interval [CI] 5.4-12.0; p < 0.001) and 12.1% at FN (CI 9.0-15.3; p < 0.001). The benefits of exercise appeared to persist after cessation of sporting activity. Active controls (n = 22) had greater BMDs than the inactive group (n = 347): 7.9% LS (CI 2.0-13.8; p = 0.009) and 8.3% FN (CI 2.7-13.8; p = 0.004). The low activity controls (n = 216) had an intermediate BMD. Tennis players had greater BMDs compared with runners: 12.0% LS (CI 5.7-18.2; p = 0.0004) and 6.5% FN (CI -0.2-13.2; p = 0.066). The BMD of tennis players' dominant forearms were greater than their nondominant forearms. In conclusion, regular vigorous weight-bearing exercise of 1 h or more per week is associated with an increase in BMD within a normal population. This study confirms long-term weight-bearing exercise as an important factor in the regulation of bone mass and fracture prevention.

Association of pain with radiological changes in different compartments and views of the knee joint

The aim of this study was to examine the association between radiological patellofemoral and tibiofemoral osteoarthritis and knee symptoms in a population-based survey. Two hundred and fifty unrelated, normal individuals (500 knees) were included in the study. Anteroposterior (AP), lateral and skyline radiographs on each individual were graded for joint space narrowing and osteophytes using a standard atlas. Radiographic features were assessed on their ability to predict knee pain for 15 or more days in the last month, the last year or pain "ever'. The presence of osteophytes had the strongest association with knee pain "ever' with an odds ratio (95% Cl) for skyline osteophytes of 7.56 (3.84-14.81) and anteroposterior osteophytes of 5.00 (2.40-10.43). The presence or absence of joint space narrowing in all the radiological views (AP, lateral and skyline) was not significantly associated with knee pain, but there was a trend for an association with severity of narrowing in the lateral and skyline views. The presence of osteophytes in all knee views (AP, lateral or skyline) was best at predicting knee pain in the last year. Osteophytes predict pain more accurately than narrowing on all knee radiographic views (AP, lateral or skyline). Pain in the last year (defined as two or more episodes of pain, each lasting for at least 15 days and not related to recent trauma) is predicted more accurately than pain in the last month or ever having had an episode of knee pain and is a useful symptom for inclusion in population studies.

Risk of osteoarthritis associated with long-term weight-bearing sports: a radiologic survey of the hips and knees in female ex-athletes and population controls

OBJECTIVE

To estimate the risk of osteoarthritis (OA) of the hip and knee due to long-term weight-bearing sports activity in ex-elite athletes and the general population.

METHODS

A retrospective cohort study was conducted of 81 female ex-elite athletes (67 middle- and long-distance runners, and 14 tennis players), currently ages 40-65, recruited from original playing records, and 977 age-matched female controls, taken from the age-sex register of the offices of a group general practice in Chingford, Northeast London, England. The definition of OA included radiologic changes (joint space narrowing and osteophytosis) in the hip joints, patellofemoral (PF) joints, and tibiofemoral (TF) joints.

RESULTS

Compared with controls of similar age, the ex-athletes had greater rates of radiologic OA at all sites. This association increased further after adjustment for height and weight differences, and was strongest for the presence of osteophytes at the TF joints (odds ratio [OR] 3.57, 95% confidence interval [95% CI] 1.89-6.71), at the PF joints (OR 3.50, 95% CI 1.80-6.81), narrowing at the PF joints (OR 2.97, 95% CI 1.15-7.67), femoral osteophytes (OR 2.52, 95% CI 1.01-6.26), and hip joint narrowing (OR 1.60, 95% CI 0.73-3.48), and was weakest for narrowing at the TF joints (OR 1.17, 95% CI 0.71-1.94). No clear risk factors were seen within the ex-athlete groups, although the tennis players tended to have more osteophytes at the TF joints and hip, but the runners had more PF joint disease. Within the control group, a small subgroup of 22 women who reported long-term vigorous weight-bearing exercise had risks of OA similar to those of the ex-athletes. Ex-athletes had similar rates of symptom reporting but higher pain thresholds than controls, as measured by calibrated dolorimeter.

CONCLUSION

Weight-bearing sports activity in women is associated with a 2-3-fold increased risk of radiologic OA (particularly the presence of osteophytes) of the knees and hips. The risk was similar in ex-elite athletes and in a subgroup from the general population who reported long-term sports activity, suggesting that duration rather than frequency of training is important.

Requirement for two conserved cysteine residues in the Ada protein of Escherichia coli for transactivation of the ada promoter

Cysteine residue 69 of the Escherichia coli Ada transcription factor, which accepts a methyl group from methylphosphotriester in methylated DNA, was substituted by each of 19 other amino acids. Only the mutant Ada (C69H), carrying a histidine substitution of Cys69, exhibited a limited degree of transactivating potential for the ada promoter in E. coli cells although the mutant protein was completely devoid of methylphosphotriester-DNA methyltransferase activity. Using a multicopy plasmid system for the expression of Ada protein, we have shown that Ada C69H has a transactivating capacity equivalent to that of wild-type Ada protein in the absence of an alkylating agent. This indicates that the zinc-binding capacity of histidine at residue 69 is likely to be sufficient for Ada to recognize and bind to the ada promoter. Furthermore, transactivation of the ada promoter by Ada C69H was enhanced up to 6-fold by treatment with methylating agents. An additional substitution was made with alanine in Ada C69H, replacing Cys321, the site for acceptance of a methyl group from O6-methylguanine and O4-methylthymine residues in DNA, with alanine. This renders the protein completely inactive as a methyltransferase but this derivative is constitutively active as a transactivator for the ada promoter. Therefore, acquisition of a methyl group at Cys321 apparently enhances the transactivating capacity of Ada protein on the ada promoter. We propose that the transcription-regulating function of Ada protein is under dual control by methylation of cysteine residues at positions 69 and 321; the former enhances DNA binding, while the latter enhances the transactivating capacity of the protein.

The correlation between the intake of lutein, lycopene and beta-carotene from vegetables and fruits, and blood plasma concentrations in a group of women aged 50-65 years in the UK

The correlations between the mean of 4 d weighed intakes of lutein, lycopene and beta-carotene and mean plasma concentrations during each of the four seasons were lutein r 0.64, lycopene r 0.47 and beta-carotene r 0.45. Intake was not significantly correlated with plasma concentrations during every seasonal time-point. There was a significantly higher intake of lutein during the spring compared with summer and autumn, lycopene intake was significantly higher during the summer and autumn and there were no significant seasonal differences in beta-carotene intake. There were, however, significant seasonal differences in plasma carotenoid concentrations, the highest levels occurring between May and October. There were large inter- and intra-individual variations in intake and plasma concentrations of carotenoids. BMI was inversely correlated with plasma beta-carotene (r-0.41). The findings suggest that plasma carotenoid concentrations are indicative of dietary intake, but the large intra-individual variation in plasma concentrations indicates that any assessment of longer-term status from data at any one time-point should be treated with caution.

Choosing the best method for radiological assessment of patellofemoral osteoarthritis

OBJECTIVE

To assess the reproducibility of different methods of radiological assessment of patellofemoral osteoarthritis (OA) and to determine which is the best view as a research tool in epidemiological studies of knee OA requiring explicit diagnostic criteria to classify the disease in the general population.

METHODS

A population based study of 252 unrelated, normal individuals (504 knees) was performed. Lateral and skyline radiographs from each individual were graded for joint space narrowing and osteophytes using a standard atlas. Reproducibility was assessed by two observers on 50 knees. Radiographic features were assessed on their ability to predict knee pain.

RESULTS

The skyline views performed better than the lateral views in the assessment of patellofemoral joint OA. The reproducibility for osteophytes was high (kappa > 0.8) and that for joint space narrowing moderate (kappa > 0.6) for both lateral and skyline views. Although the specificity for detecting knee pain was similar in both views, the sensitivity of skyline views in the assessment of knee pain was greater (52.8% versus 30%). The odds ratio for skyline osteophytes as a predictor of knee pain was 7.66 (95% confidence interval (CI) 3.68 to 15.90); that for osteophytes seen on lateral view was 1.83 (95% CI 0.96 to 3.49). Narrowing on both views was a poor predictor of pain. There was frequent disagreement between the lateral and skyline views for detecting osteophytes.

CONCLUSION

In a community based study, skyline views performed better than lateral views in terms of reproducibility and for identifying symptomatic patellofemoral joint OA. Skyline radiographs should be the preferred method for examining the patellofemoral joint in such studies.

Spiking of the tibial tubercles--a radiological feature of osteoarthritis?

OBJECTIVE

To determine whether 'spiking' or angulation of the tibial tubercle is associated with other radiographic markers of osteoarthritis (OA) or pain in the knee joint, and could be taken as a reliable marker for early OA, in a large general population sample.

METHODS

A total of 950 women from the Chingford general population survey underwent anteroposterior extended weight bearing radiography of the knees. Angulation of the tip of the medial and lateral tubercles, and height of the tubercles above the tibial plateau were measured. These measures were compared with standard radiographic indices including qualitative Kellgren and Lawrence global score, individual scores of osteophytes and joint space narrowing, and pain score. Intraobserver and interobserver reproducibility for assessment of spiking was tested in a subgroup of 50 films using two observers and two readings. Tibial spiking (angulation and height) was defined for this study as the top 10th centile for the whole population. Patients with normal radiographs (Kellgren and Lawrence grade 0) were allocated to quartile groups on the basis of spiking to define severity. Odds ratios were then calculated for the association of spiking and knee pain.

RESULTS

The majority of the measures of tibial spiking were highly reproducible. There was a significant correlation between tibial spike angulation and the presence of osteophytes, but not joint space narrowing. The correlations for spike height with osteophytes and joint space narrowing were poor. There was an association between spike angulation at the lateral tubercle and reported knee pain (odds ratio 1.45 (95% confidence interval 1.03 to 2.03)) after adjustment for age, body mass index, and Kellgren and Lawrence score. There was no association between medial spike angulation or spike height and pain. Among the 950 women, 683 (72%) had normal radiographs (Kellgren and Lawrence = 0); in this group there was a similar association between pain and lateral spike angulation, but not medial spike angulation or spike height.

CONCLUSIONS

Tibial spiking is associated with the presence of knee osteophytes and is reproducible, but does not have a strong independent relationship with knee pain. In patients with normal radiographs there is no useful correlation between tibial spiking and pain. Isolated tibial spiking is not a reliable sign of early knee OA, and should not routinely be reported.

Patterns of joint involvement in osteoarthritis of the hand: the Chingford Study

OBJECTIVE

The hand is the major site of joint involvement in osteoarthritis (OA), but the clustering of this condition at different joint sites within the hand as part of an entity known as generalized OA remains contentious. We examine this issue in a population sample of 967 peri and postmenopausal women.

METHODS

The pattern of radiographic involvement of hand joints was examined using the Kellgren and Lawrence system in a sample of women aged 45-64 years, selected from the general population in Chingford, East London. Log linear modelling techniques were used to examine clustering of OA in different joint sites and to examine whether this clustering remained significant after age adjustment.

RESULTS

There was clear evidence of clustering in joint involvement: Thus 20 women had 4 or more affected joints compared with only 2 expected (chi 2 = 72.0, 4df, p < 0.001). The risk of multiple distal interphalangeal (DIP) joint involvement, after age adjustment, in a woman with a single affected DIP joint was significantly increased (OR 10.0, 95% CI 7.3-13.7) and was substantially greater than the corresponding risk for proximal interphalangeal joint (OR 3.1, 95% CI 1.4-6.8) involvement. Symmetry was the strongest determinant of pattern with an OR 38.8 (95% CI 14.5-103.5) for corresponding DIP joint involvement in the contralateral hand.

CONCLUSION

These data provide clear evidence for a polyarticular subset of hand OA in women. There are 3 major determinants of the pattern of polyarticular involvement; symmetry, clustering by row and clustering by ray, in descending order of importance.

Association between metabolic factors and knee osteoarthritis in women: the Chingford Study

OBJECTIVE

Several studies have shown an association with density and knee osteoarthritis (OA), however the role of other metabolic factors is unclear, with conflicting data in the literature. We studied the association between metabolic risk factors and k nee OA in women in the general population.

METHODS

One thousand three women aged 45-64 from the Chingford population study completed risk factor questionnaires. Current blood pressure and ever hypertension were noted and fasting blood glucose, serum cholesterol, triglycerides, high density lipoprotein( HDL), and uric acid levels were measured. AP weight bearing radiographs were available in 979 women and scored using the Kellgren and Lawrence system. Grade 2+ (definite osteophytes) was used a definition of knee OA. Odds ratios (OR) and 95% confidence intervals were calculated for risk of knee OA in highest tertile versus lowest for death risk factor. All OR were adjusted for age and body mass index as potential confounders for OA.

RESULTS

Radiological evidence of knee OA was found in 118 women (12%). For knee OA in either knee the variables significantly associated were raised blood glucose OR = 1.95 (1.08-3.59), and moderately raised serum cholesterol OR = 2.06 (1.06-3.98). For symptomatic women (n = 58) raised blood glucose OR = 2.77 (1.13-6.76), and use of diuretics OR = 2.27 (1.11-4.65) were significantly associated. For bilateral knee disease (n = 55) significant associations were found for ever hypertension OR = 3.02 (1.51-6.06), subjects taking diuretics OR = 2.84 (1.37-5.89), and both high and moderately raised serum cholesterol OR = 3.91 (1.07-14.25), and OR = 3.63 (1.00-13.88), respectively. In all categories of knee OA serum uric acid was nonsignificantly increased. No association was found with raised triglyceride or HDL levels or with current systolic blood pressure. Further adjustment for physical activity and social class did not affect the results.

CONCLUSION

These data suggest that hypertension, hypercholesterolemia, and blood glucose are associated with both unilateral and bilateral knee OA independent of obesity, and support the concept that OA has an important systemic and metabolic component in its etiology.

The classification and assessment of osteoarthritis

Osteoarthritis is the commonest rheumatic disease, but despite its high prevalence in the elderly, associated disability and public health costs, there is little understanding of the aetiology of the disease. Questions still remain unanswered: 'what do we mean by the term osteoarthritis?; how do we define it?; how do we classify patients with the disease?; how do we differentiate between cases for population studies, and clinically relevant disease the physician wishes to treat?'. This chapter has demonstrated the considerable advances that have been made over the last thirty years in solving these issues, but we are still lacking a universal definition and classification of the disease. Defining and classifying OA is not an easy task, as it is not a single disease, but rather a spectrum of diseases that are the end result of a number of different processes. However, in order to understand the aetiology and natural course of the disease, and to devise appropriate treatment strategies, correct definition of OA at distinct sites is vital. Radiological site-specific definition of the disease is now recognized as the major tool available in defining OA. There is general consensus that the grading of osteophytes and joint space narrowing at the major sites using validated atlases is an important step forward.

Radiographic criteria for epidemiologic studies of osteoarthritis

For the purpose of epidemiologic studies in osteoarthritis (OA) an agreed criteria set is required that is both reliable and reproducible. A standardized method of radiologic classification will promote better reporting of epidemiologic data and consistency between centers. The radiographic scoring system of Kellgren and Lawrence has been used in OA research for over 30 years. Its deficiencies include the lack of clarity in interpretation and its reliance on the presence of the osteophyte. Recent advances suggest other pathological evidence of OA on radiographs should be measured when assessing OA. There is growing consensus that while a global score is still useful, the separate features should be recorded in a semiquantitative fashion using standardized atlases allowing different emphasis of particular features at different sites.

The progression of radiological hand osteoarthritis over ten years: a clinical follow-up study

The natural history of hand osteoarthritis (OA) is poorly understood. The aim of the study was to ascertain the extent and pattern of radiological progression of hand OA over a 10-year period. A follow-up study was carried out on 169 consecutive patients who initially presented with OA of the hands or knees between 1975-1977. Fifty-nine subjects (45 women and 14 men) were recontacted who had paired hand radiographs, a mean of 10 years apart, and were a mean 69 (range 53-86) years old at follow-up. X-rays were scored blind, in three joint areas--distal and proximal interphalangeal joints (DIP and PIP) and first carpo-metacarpal (CMC) joints--using the method of Kellgren and Lawrence (K&L) (0-4), and for osteophytes and narrowing (0-3). Using the highest score for right and left hands (N = 118), K&L changes at the three areas were similar with 47-50% deteriorating, 45-46% unchanged, and 6-8% improving. Similar deterioration was seen when scoring the three joint areas for osteophytes (38-39%) and narrowing (39-48%). New osteophytes appeared in 48% of DIP joints during the 10 years. There was a weak correlation between progression at the DIP and PIP joints, but no relationship between DIP and CMC, or CMC and PIP. Virtually all subjects (97%) deteriorated when the total scores of all joints were calculated. No significant differences were seen between 'severe progressors' and 'minor' in terms of age or body mass index (BMI). A nonsignificant increase in the proportion of knee progressors in the severe progressor hand group was seen and there was a higher rate of baseline DIP OA in knee progressors. These results suggest that the majority of patients with OA of the hands attending a rheumatology outpatients clinic deteriorate radiologically over a 10-year period, about half developing new changes in DIP joints. There were no obvious features distinguishing those with rapid deterioration, although DIP OA appears to be a risk factor for knee progression.

Incidence and progression of osteoarthritis in women with unilateral knee disease in the general population: the effect of obesity

OBJECTIVES

The natural history of knee osteoarthritis (OA) is poorly understood. The principal aim was to assess the rate of contralateral knee OA in middle aged women in the general population with existing unilateral disease and to identify the major factors that influence this rate.

METHODS

Fifty eight women aged (45-64) from a general population study cohort were identified with unilateral knee OA diagnosed radiologically (Kellgren and Lawrence 2+) (K&L). Follow up AP films were obtained at 24 months and compared with the baseline for K&L grade and individual features of osteophytes and joint space.

RESULTS

Twenty women (34%) developed incident disease in the contralateral knee (based on K&L 2+ or osteophyte changes) and 22.4% (n = 13) of women progressed radiologically in the index joint. Obesity at baseline was the most important factor related to incident disease, 47% of women in the top BMI tertile developed OA, compared with 10% in the lowest tertile: relative risk 4.69 (063-34.75). No clear effect was seen for age, physical activity, trauma or presence of hand OA.

CONCLUSIONS

Over one third of middle aged women with unilateral disease will progress to bilateral knee OA within two years and a fifth will progress in the index joint. Obesity is a strong and important risk factor in the primary and secondary prevention of OA. These natural history data provide a useful estimate for planning therapeutic intervention trials.

Primary biliary cirrhosis presenting with granulomatous skin lesions

A case is described of primary biliary cirrhosis in a 59 year old woman who initially presented with a rash over her lower legs 18 months before diagnosis. Skin biopsy examination showed non-caseating granulomas of the sarcoid type. It is believed that this is the first reported case of primary biliary cirrhosis presenting with a granulomatous rash.

The relationship between osteoarthritis and osteoporosis in the general population: the Chingford Study

OBJECTIVE

A total of 979 women from the Chingford general population survey were studied to examine the hypothesis that osteoarthritis (OA) and osteoporosis are inversely related.

METHODS

All women had radiographs of the hands and knees. A total of 579 also had AP radiographs of the lumbar spine which were graded for the presence of osteophytes. All women had bone densitometry performed at the lumbar spine (L1-L4) and femoral neck. Mean bone densities (BMD) were compared between those with disease and those with no disease at any other sites. All results were adjusted for age and body mass index (BMI).

RESULTS

All OA groups had significantly higher bone density than controls at the lumbar spine. For distal interphalangeal (DIP) OA (n = 140) the difference was +5.8% (+3.0, +8.6), for carpometacarpal (CMC) OA (n = 160) +3.0% (+0.1, +5.9), for knee OA (n = 118) +7.6% (+4.3, +10.9), and lumbar spine OA (LSOA) (n = 194) +7.8% (+6.0, +8.8). Those with generalised OA (GOA n = 22), a combination of knee, DIP and CMC OA had an increase of +9.3 (+2.0, +16.6). For the femoral neck BMD was also increased significantly ranging from +2.5% for the CMC, +6.2% for the knee and +6.3% in the lumbar spine OA group. The risk of knee OA for women in the top tertile of BMD was 2.13 (1.15-3.93). Additional adjustment for other confounders such as smoking, alcohol, exercise, HRT, social class and spine osteophytes did not alter the results.

CONCLUSIONS

These results suggest that small increases in BMD are present in middle aged women with early radiological OA of the hands, knees and lumbar spine. These data support the hypothesis that the two conditions are inversely related, although the mechanisms remain unclear.

Definition of osteoarthritis of the knee for epidemiological studies

OBJECTIVES

There are no agreed criteria for osteoarthritis (OA) of the knee in population studies. The radiographic scoring system of Kellgren and Lawrence has been the system most used in the past and although other methods have been developed, comparisons have not been performed. Therefore these grading systems were compared in radiographs from a general population sample.

METHODS

Anteroposterior weightbearing radiographs of 1954 knees from 977 women aged 45-64 years from the Chingford population study were read by a variety of methods, including quantitative measures of minimum joint space, qualitative measures of osteophytes and of joint space, and a qualitative Kellgren and Lawrence global score. All qualitative methods used standardised atlases. Intra-observer and interobserver reproducibility was tested on a subgroup of 100 films using three observers and two readings. Variables were dichotomised at the tenth and second centiles to define OA. Odds ratios were calculated for each method for the association of OA with knee pain, obesity, and with each of the other methods.

RESULTS

Most methods had high intraobserver and interobserver reproducibility, except for measurements of lateral joint space. The best predictors of knee pain were the presence of osteophytes and the Kellgren and Lawrence grade. Methods measuring narrowing performed less well, with measurements of lateral joint space being particularly poor. Similar results were achieved in the comparison with obesity and in the comparisons between methods.

CONCLUSIONS

These data suggest that the presence or absence of a definite osteophyte read by a single observer with an atlas is the best method of defining OA of the knee for epidemiological studies in women. Assessment of narrowing may be better used in evaluating severity.

Increased levels of urinary collagen crosslinks in females with rheumatoid arthritis

Bone loss is a feature of RA, but the exact mechanisms involved are not clear. The collagen crosslinks deoxypyridinoline (DPYR) and pyridinoline (PYR) are specific indices of 'mature' collagen breakdown and reflect increased bone turnover. The aims of the study were to examine crosslink levels in RA and their association with disease activity and the effect of steroids. Urinary crosslinks corrected for creatinine were measured on morning fasting samples by HPLC in 70 postmenopausal women with rheumatoid arthritis (RA) aged 45-65 and compared with 169 postmenopausal healthy age-matched controls from the population. Mean levels of PYR were significantly higher in RA cases than in controls (52.4 versus 37.5 nmols/mmolCr) although mean levels of DPYR did not differ significantly. A weak correlation was found with ESR and PYR (r = 0.35) but not with other markers of disease activity. Thirteen of the RA cases were current steroid users and their levels of DPYR and PYR even with low doses, were significantly elevated above those of non-users, ex-users and controls. The finding of raised urinary PYR but not the bone specific DPYR in nonsteroid using RA cases suggests that the increased collagen breakdown does not primarily come from bone but from other sources such as cartilage and synovium. The large increases in collagen excretion in low dose steroid users, may reflect the higher risk of osteoporosis in this group.

Prevalence of rheumatoid arthritis and rheumatoid factor in women: evidence for a secular decline

OBJECTIVE

To determine the current prevalence of rheumatoid arthritis (RA) and rheumatoid factor positivity in the United Kingdom middle aged female population and to compare this with previous estimates to assess whether the disease is becoming less prevalent.

METHODS

A cross sectional prevalence study was undertaken. All women aged 45-64 from the age and sex register of a large 11,000 general practitioner group practice in Chingford, East London were contacted and responders examined clinically and radiographically for the presence of RA by a single observer. Blood was also taken for rheumatoid factor testing (sheep cell agglutination test (SCAT), latex, and IgG). The prevalence in non-attenders was assessed from general practitioner and local hospital records. A diagnosis of definite or classical RA according to 1958 American Rheumatism Association criteria was used, and seropositivity was defined by a SCAT rheumatoid factor of 1/32 or more.

RESULTS

From the 1003 women examined (response rate of 78.8%), 12 women had definite RA (1.2%, 95% confidence interval 0.6 to 1.8). Of these, 7/12 had definite erosive changes on radiography and 3/12 had a positive SCAT (> 1/32). Three cases of RA were also found in the 284 non-responders (prevalence 1.1%) by case-finding techniques. The rate of SCAT positivity in the whole study group was 0.5%. The rates of RA and SCAT positivity currently found in this group were less than those obtained in previous surveys. In the only previous large scale United Kingdom survey, performed in the north of England between 1958 and 1960, 406 women aged 45-64 were examined and 10 cases of definite RA were found, a prevalence of 2.5%. In the patients with RA 68% had erosions and 63% positive SCAT. The population SCAT positive rate in this and other surveys sampled between 1954 and 1961 was in the range of 4-5%, since when there has been a progressive decline according to a number of other studies.

CONCLUSIONS

The prevalence of RA and rheumatoid factor in middle aged women is lower than previously believed and supports a variety of other data which indicate that RA is declining in incidence and severity.

Cigarette smoking and risk of osteoarthritis in women in the general population: the Chingford study

Previous studies have suggested that smoking might be protective against the development of osteoarthritis (OA) of the knee. A group of 1003 women aged 45-64 years (mean 54.2 years) from the Chingford general population survey were studied to examine the effect of cigarette smoking on the prevalence of radiologically confirmed OA at different sites. Standard anteroposterior radiographs of the hand and knee were available in 985 women. Disease classification was made on the basis of radiological OA and symptomatic radiological OA. Odds ratios were calculated and adjusted for age and body mass index. A total of 463 (46.2%) women were ever smokers compared with 540 (53.8%) non-smokers. Ever smokers had consumed an average of 14.9 cigarettes a day for a mean of 25.7 years. For radiological OA of the distal interphalangeal joint (DIP) (140 women), proximal interphalangeal joint (40 women), carpometacarpal joint (160 women), and knee joint (118, women) there was no reduced risk of OA in ever smokers. In the small number of subjects with generalised OA (22 women) there was a non-significant 40% reduction of radiological OA in ever smokers (odds ratio 0.63; 95% confidence interval 0.24 to 1.68). Results were similar for subjects with radiographic clinical OA, except the DIP joint which showed a positive association between smoking and Heberden's nodes (odds ratio 2.02, 95% confidence interval 1.89 to 3.42). Results were similar when analysed using current smokers against never smokers. These results do not support an inverse association between cigarette smoking and OA in women. A possible inverse relation with the small subgroup of women with generalised OA and an effect of cigarettes on disease severity cannot, however, be discounted.

The relationship of obesity, fat distribution and osteoarthritis in women in the general population: the Chingford Study

One thousand and three women aged 45-64 from the Chingford general population survey were studied cross sectionally to find the effect of quantity and distribution of body fat on the prevalence of radiologically confirmed osteoarthritis (OA) in the knee, carpometacarpal (CMC), distal interphalangeal (DIP), and proximal interphalangeal (PIP) joints. Obesity was classified as the upper tertile of body mass index (BMI kg/m2); the boundaries of the middle tertile were 23.4 and 26.4 kg/m2. The age adjusted odds ratio (OR) [and 95% confidence interval (CI)] of radiographic OA at the knee comparing the high and low tertile of BMI was 6.17 (3.26-11.71) and for bilateral knee radiographic OA was 17.99 (6.25-51.73). Comparing the middle and low tertile of BMI, the odds ratio for radiographic OA knee was 2.86 (1.44-5.68). For other joints the association between BMI and radiographic OA was less strong; the OR at CMC was 1.71 (1.05-2.78), at DIP was 1.52 (0.90-2.57), and at PIP was 1.23 (0.52-2.91). For all joints except PIP these OR increased if the diagnostic criteria included knee pain for at least a month, clinically evident swelling at the DIP or PIP, and pain or tenderness at the CMC. Recalled weight at age 20 years, or recalled maximum weight improved prediction of radiographic OA from current BMI, but measurement of fat distribution from circumference of waist, hip and thigh did not. Our results confirm that excess body weight is a powerful predictor of OA of the knee in middle aged women, and a modest predictor of DIP and CMC OA.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary collagen crosslinks reflect the radiographic severity of knee osteoarthritis

The collagen crosslinks deoxypyridinoline and pyridinoline are indices of mature collagen breakdown and reflect increased bone turnover. Urinary levels were found to be significantly raised in a group of 59 women with knee OA compared to 110 female controls from the general population. Levels of the crosslinks correlated significantly with X-ray grade of all subjects including women from the general population with mild, often asymptomatic, disease. These correlations were not diminished after adjustment for age and weight.

Keratan sulphate in rheumatoid arthritis, osteoarthritis, and inflammatory diseases

Serum concentrations of antigenic keratan sulphate determined by an enzyme linked immunosorbent assay (ELISA) with a monoclonal antibody were studied in patients with rheumatoid arthritis (RA), osteoarthritis, ankylosing spondylitis, other inflammatory diseases, and a large control group of women without arthritis. Mean keratan sulphate concentrations were low in 117 women with RA compared with 227 female control subjects matched for age drawn from a community survey. There were significant correlations between serum keratan sulphate concentrations in patients with RA and serum C reactive protein and the erythrocyte sedimentation rate. Serum keratan sulphate concentrations were also low in 29 men and women with ankylosing spondylitis and 29 patients with arthritis and high concentrations of C reactive protein. In 98 women undergoing an operation for benign breast disease there were decreases in serum keratan sulphate concentrations after the operation which correlated with doses in serum C reactive protein. No differences were found in keratan sulphate concentrations in 137 women with osteoarthritis compared with controls. Within the group with osteoarthritis there were no differences for the various joint groups and there was no obvious correlation with radiographic severity or progression. These findings suggest serum keratan sulphate is unlikely to be useful as a diagnostic marker in osteoarthritis or RA but indicate a role for inflammation in the regulation of cartilage loss.

Frequency of osteoarthritis in hysterectomized women

A previous retrospective study reported a 2-fold increase in hysterectomy rates in women outpatient clinical attenders with osteoarthritis (OA) compared to controls. Our study was undertaken to confirm the findings of a previous case-control study which suggested hysterectomy to be a risk factor for OA. A retrospective cohort study design was used that would reduce the problems of selection bias. One hundred and sixty-two women who had undergone a hysterectomy between 1978 and 1979 (current mean age 53.8) and 164 controls (mean age 54.1) were examined for peripheral joint OA between 1988 and 1989. The screening method was identical for both groups and included a questionnaire, systematic examination of certain joints and radiographs of hands and knees. Women with a previous hysterectomy were found to have significantly higher rates of clinical signs of knee OA and 1st carpometacarpal (CMC) OA than control women without hysterectomy. The results were confirmed when OA was classified by the presence of symptoms alone, and when only radiologically confirmed clinical cases were included. The application of radiological criteria showed significantly smaller medial joint spaces (by digital image analysis) in hysterectomized women, although no differences were found using the Kellgren and Lawrence grading system. The increased risk for knee and CMC persisted after adjustment for possible confounders including age, obesity, parity and smoking status. By contrast frequency of distal interphalangeal and proximal interphalangeal involvement was lower, though not significantly so, than in controls.

Clinical signs of early osteoarthritis: reproducibility and relation to x ray changes in 541 women in the general population

The definition and classification of early clinically apparent osteoarthritis both in clinical situations and in epidemiological surveys remains a problem. Few data exist on the between-observer reproducibility of simple clinical methods of detecting hand and knee osteoarthritis in the population and their sensitivity and specificity as compared with radiography. Two observers first studied the reproducibility of a number of clinical signs in 41 middle aged women. Good rates of agreement were found for most of the clinical signs tested (kappa = 0.54-1.0). The more reproducible signs were then tested on a population of 541 women, aged 45-65, drawn from general practice, screening centres, and patients previously attending hospital for non-rheumatic problems. The major clinical signs used had a high specificity (87-99%) and lower sensitivity (20-49%) when compared with radiographs graded on the Kellgren and Lawrence scale (2+ = positive). When analysis was restricted to symptomatic radiographic osteoarthritis, levels of sensitivity were increased and specificity was lowered. These data show that certain physical signs of osteoarthritis are reproducible and may be used to identify clinical disease. They are not a substitute for radiographs, however, if radiographic change is regarded as the 'gold standard' of diagnosis. As the clinical signs tested seemed specific for osteoarthritis they may be of value in screening populations for clinical disease.

The use of radiographs in assessing the severity of knee osteoarthritis

Conventional radiographic grading of the knee has been used for 30 years and is based around the presence of osteophytes. About 50% of subjects from the general population meeting traditional radiographic criteria are asymptomatic or have no signs of clinical disease. Recent development in the use of different radiographic grading systems involve more attention to joint space and categorization of discrete radiographic findings. These techniques include new grading scales that use a combination of separate radiographic features; microfocal radiography and digitized image analysis of joint space. It is hoped these might reflect more closely the pathological processes and correlate more closely with clinical severity.

Detection of a human intracisternal A-type retroviral particle antigenically related to HIV

Sjögren's syndrome is an autoimmune disease that is characterized by dryness of the mouth and eyes. The loss of salivary and lacrimal gland function is accompanied by lymphocytic infiltration. Because similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV), a search was initiated for a possible retroviral etiology in this syndrome. A human intracisternal A-type retroviral particle that is antigenically related to HIV was detected in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjögren's syndrome. Comparison of this retroviral particle to HIV indicates that they are distinguishable by several ultrastructural, physical, and enzymatic criteria.

Detection of serum antibodies to retroviral proteins in patients with primary Sjögren's syndrome (autoimmune exocrinopathy)

Primary Sjögren's syndrome (SS) is considered a benign autoimmune disease; it is characterized by lymphoid infiltration of salivary and lacrimal glands, often accompanied by the presence of serum autoantibodies, particularly anti-Ro (SS-A) and anti-La (SS-B). There are important immunologic similarities between primary SS and acquired immunodeficiency syndrome. To investigate for a possible immune response to retroviral proteins in primary SS, we performed immunoblotting against human immunodeficiency virus-1 (HIV-1) proteins using sera from 47 patients with primary SS. Moderate-to-strong reactivity, suggesting the presence of serum antibodies, was found in 14 patients (30%). Of 120 normal subjects, only 1 showed moderate positivity. All 14 positive SS sera reacted against p24 (gag) but failed to react against gp41 or gp120 (env). This response did not reflect hypergammaglobulinemia since immunoglobulin concentrations among the 29 SS patients studied were the same in sera that contained and sera that did not contain anti-gag reactivity. Two sera also reacted against p17 gag. Four reacted against HIV-2 core proteins, but none reacted with core proteins of human T lymphotropic virus-I. Only 1 of the 14 sera reacted against Ro (SS-A), and 1 other reacted against La (SS-B). These results identify a subset of SS patients characterized by 1) the presence of serum antibodies to HIV-1 group-specific, but not type-specific, proteins, and 2) the relative absence of anti-Ro (SS-A) and anti-La (SS-B) autoantibodies. In this latter respect, these SS patients constitute a subpopulation that resembles patients with HIV-induced SS-like disease.

Changes in the hydrophobic-hydrophilic cell surface character of Halomonas elongata in response to NaCl

Phase-partitioning studies of the euryhaline bacterium Halomonas elongata demonstrated that the hydrophobic-hydrophilic nature of the cell surface changed as the bacterium grew in different NaCl concentrations. Mid-log-phase cells grown in a high (3.4 M) NaCl concentration were more hydrophilic than were cells grown in a low (0.05 M) NaCl concentration. Mid-log-phase cells from defined medium containing 3.4 M NaCl normally produced a hydrophobicity reading of only 14 (hexadecane hydrophobicity = 100), while corresponding cells from defined medium containing 0.05M NaCl gave a hydrophobicity reading of 90. Compared with cells grown in low salt concentrations, cells grown in high salt concentrations were more hydrophilic at all stages of growth. Rapid suspension of log-phase cells grown in 1.37 M NaCl into a 0.05 or 3.4 M NaCl solution produced no detectable rapid changes in surface hydrophobicity. These data suggest that as H. elongata adapts to different NaCl concentrations, it alters the affinity of its outermost cell surface to water.

Ester-imine condensations: preparation of racemic intermediates for the synthesis of the carbapenem antibiotics PS-5 and PS-6

The lithium enolates of ethyl butyrate and ethyl isovalerate react with N-p-methoxyphenylcinnamaldimine in tetrahydrofuran (THF)-hexamethylphosphoric triamide (HMPA) to afford predominantly trans beta-lactams 9 (67%) and 20 (78%), respectively. beta-Lactam 9 was converted to PS-5 intermediate 18 in 21% overall yield (8 steps). Beta-lactam 20 was converted to PS-6 analog 28 in 22% overall yield using an eight step sequence.

Iatrogenic metatarsal coalition: a postoperative complication of adjacent V-osteotomies

The authors present a case report of iatrogenic metatarsal coalition, a postoperative complication of adjacent V-osteotomies. The paper also includes a discussion of surgical considerations of multiple adjacent osteotomies contributing to such a sequela, including adequate irrigation, instrumentation, anatomy, and the use of corticosteroids.