MRI of the wrist in early rheumatoid arthritis can be used to predict functional outcome at 6 years

OBJECTIVES

To determine whether magnetic resonance (MR) scans of the dominant wrist of patients with early rheumatoid arthritis (RA) can be used to predict functional outcome at 6 years' follow up.

METHODS

Dominant wrist MR scans were obtained in 42 patients with criteria for RA at first presentation. Patients were followed up prospectively for 6 years, and further scans obtained at 1 year (42 patients) and 6 years (31 patients). Two radiologists scored scans for synovitis, tendonitis, bone oedema, and erosions. The Stanford Health Assessment Questionnaire (HAQ) score, indicating functional outcome, and standard measures of disease activity were assessed at 0, 1, 2, and 6 years. The physical function component of the SF-36 score (PF-SF36) was also used as a functional outcome measure at 6 years.

RESULTS

Baseline MR parameters, including bone oedema score and the total baseline MR score, were predictive of the PF-SF36 at 6 years (R2 = 0.22, p = 0.005 and R2 = 0.16, p = 0.02, respectively). The PF-SF36 score correlated strongly with the HAQ score at 6 years (rs = -0.725, p<0.0001); none of the baseline MR parameters predicted the 6 year HAQ score. The total MR score obtained at 1 year was predictive of the 6 year HAQ (R2 = 0.04, p = 0.01). Standard clinical and radiographic measures at baseline were not predictive of the 6 year PF-SF36, but when combined in a model with baseline MR oedema score, prediction increased from 0.09 to 0.23, or 23% of the 6 year variance.

CONCLUSION

MR imaging of the wrist in patients with early RA can help to predict function at 6 years and could be used to plan aggressive management at an earlier stage.

What is the fate of erosions in early rheumatoid arthritis? Tracking individual lesions using x rays and magnetic resonance imaging over the first two years of disease

OBJECTIVES

To investigate the progression of erosions at sites within the carpus, in patients with early rheumatoid arthritis (RA), using magnetic resonance imaging (MRI) and plain radiology over a two year period.

METHODS

Gadolinium enhanced MRI scans of the dominant wrist were performed in 42 patients with RA at baseline (within six months of symptom onset) and one year. Plain wrist radiographs (x rays) and clinical data were obtained at baseline, one year, and two years. Erosions were scored by two musculoskeletal radiologists on MRI and x ray at 15 sites in the wrist. A patient centred analysis was used to evaluate the prognostic value of a baseline MRI scan. A lesion centred analysis was used to track the progression of individual erosions over two years.

RESULTS

The baseline MRI erosion score was predictive of x ray erosion score at two years (p=0.004). Patients with a "total MRI score" (erosion, bone oedema, synovitis, and tendonitis) > or =13 at baseline were significantly more likely to develop erosions on x ray at two years (odds ratio 13.4, 95% CI 2.65 to 60.5, p=0.002). Baseline wrist MRI has a sensitivity of 80%, a specificity of 76%, a positive predictive value of 67%, and a high negative predictive value of 86% for the prediction of wrist x ray erosions at two years. A lesion centred analysis, which included erosions scored by one or both radiologists, showed that 84% of baseline MRI erosions were still present at one year. When a more stringent analysis was used which required complete concordance between radiologists, all baseline lesions persisted at one year. The number of MRI erosion sites in each patient increased from 2.1 (SD 2.7) to 5.0 (4.6) (p<0.0001) over the first year of disease. When MRI erosion sites were tracked, 21% and 26% were observed on x ray, one and two years later. A high baseline MRI synovitis score, Ritchie score, and erythrocyte sedimentation rate were predictive of progression of MRI erosions to x ray erosions over one year (p=0.005, 0.01, and 0.03 respectively), but there was no association with the shared epitope. Progression of MRI erosions to x ray erosions was not seen in those with transient polyarthritis.

CONCLUSIONS

MRI scans of the wrist, taken when patients first present with RA, can predict radiographic erosions at two years. MRI may have a role in the assessment of disease prognosis and selection of patients for more or less aggressive treatment. However, only one in four MRI erosions progresses to an x ray erosion over one year, possibly owing to healing, observer error, or technical limitations of radiography at the carpus. Progression of MRI erosions to x ray erosions is greatest in those with high baseline disease activity.

Monotreme IGF2 expression and ancestral origin of genomic imprinting

IGF2 (insulin-like growth factor 2) and M6P/IGF2R (mannose 6-phosphate/insulin-like growth factor 2 receptor) are imprinted in marsupials and eutherians but not in birds. These results along with the absence of M6P/IGF2R imprinting in the egg-laying monotremes indicate that the parental imprinting of fetal growth-regulatory genes may be unique to viviparous mammals. In this investigation, we have cloned IGF2 from two monotreme mammals, the platypus and echidna, to further investigate the origin of imprinting. We report herein that like M6P/IGF2R, IGF2 is not imprinted in monotremes. Thus, although IGF2 encodes for a highly conserved growth factor in chordates, it is only imprinted in therian mammals. These findings support a concurrent origin of IGF2 and M6P/IGF2R imprinting in the late Jurassic/early Cretaceous period. The absence of imprinting in monotremes, despite apparent interparental conflicts over maternal-offspring exchange, argues that a fortuitous congruency of genetic and epigenetic events may have limited the phylogenetic breadth of genomic imprinting to therian mammals. J. Exp. Zool. (Mol. Dev. Evol.) 291:205-212, 2001.

Marsupials and Eutherians reunited: genetic evidence for the Theria hypothesis of mammalian evolution

The three living monophyletic divisions of Class Mammalia are the Prototheria (monotremes), Metatheria (marsupials), and Eutheria ('placental' mammals). Determining the sister relationships among these three groups is the most fundamental question in mammalian evolution. Phylogenetic comparison of these mammals by either anatomy or mitochondrial DNA has resulted in two conflicting hypotheses, Theria and Marsupionta, and has fueled a "genes versus morphology" controversy. We have cloned and analyzed a large nuclear gene, the mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF2R), from representatives of all three mammalian groups, including platypus, echidna, opossum, wallaby, hedgehog, mouse, rat, rabbit, cow, pig, bat, tree shrew, colugo, ringtail lemur, and human. Statistical analysis of this nuclear gene unambiguously supports the morphology-based Theria hypothesis that excludes monotremes from a clade of marsupials and eutherians. The M6P/IGF2R was also able to resolve the finer structure of the eutherian mammalian family tree. In particular, our analyses support sister group relationships between lagomorphs and rodents, and between the primates and Dermoptera. Statistical support for the grouping of the hedgehog with Feruungulata and Chiroptera was also strong.

Magnetic resonance imaging in rheumatoid arthritis: summary of OMERACT activities, current status, and plans

Complementing the 3 papers that precede it, this paper explains the rationale for the activities of an OMERACT working party on magnetic resonance imaging (MRI) evaluation of rheumatoid arthritis (RA), sets out provisional recommendations for the acquisition and scoring of MRI of the hand and wrist in RA, and delineates some of the many residual problems that need to be addressed.

Interreader agreement in the assessment of magnetic resonance images of rheumatoid arthritis wrist and finger joints--an international multicenter study

Magnetic resonance imaging (MRI) allows direct visualization of inflammation and destruction in rheumatoid arthritis (RA) joints. However, MRI scoring methods have not yet been standardized or appropriately validated. Our aim was to examine interreader agreement for a simple system of scoring RA changes on MRI among 5 centers that had not undertaken intergroup calibration. MRI of RA wrist and metacarpophalangeal (MCP) joints were scored by experienced readers in 5 centers in different countries. In substudy 1, 5 sets of 2nd-5th MCP joints from UK [Technique A: 1.5 T, coronal and axial T1 and T2 spin-echo, -/+ fat saturation (FS), -/+ iv gadolinium (Gd)] were scored for synovitis (score 0-3) and bone lesions (0-3). In substudy 2, we evaluated 19 sets of 2nd-5th MCP joints [10 sets from UK (Technique A) and 9 sets from the US (Technique B: 1.5 T; coronal T1 spin-echo and T2* gradient-echo + FS, no Gd)] and 19 wrist joints [9 from the US (Technique B) and 10 from Denmark (Technique C: 1.0 T; coronal and axial T1 spin-echo, no FS, -/+ Gd)]. Synovitis (0-3), bone lesions (0-3), and joint space narrowing (JSN, 0-3) were scored in each MCP joint and in 3 different regions of the wrist. Bone erosions and lesions in each bone were scored 0-5. Substudy 1 served to test and redesign the score sheets. In substudy 2, the scores of synovitis and bone lesions by the 5 groups were the same or differed by only one grade in 73% and 85% of joints, respectively. On MRI that included 2 imaging planes and iv Gd (Techniques A and C), these rates were 86% (synovitis) and 97% (bone lesions). Corresponding intraclass correlation coefficients (quadratic weighted kappas) were 0.44-0.68, mean 0.58 (synovitis), and 0.44-0.69, mean 0.62 (bone lesion), i.e., in the moderate to good range. Unweighted kappa values were in the low to moderate range, generally lowest for JSN (< 0.20), better for synovitis and bone erosions, and best for bone lesions, being generally highest for MRI with 2 planes pre- and post-Gd and in MCPjoints compared with wrists. These preliminary results suggest that the basic interpretation of MRI changes in RA wrist and MCP joints is relatively consistent among readers from different countries and medical backgrounds, but that further training, calibration, and standardization of imaging protocols and grading schemes will be necessary to achieve acceptable intergroup reproducibility in assessing synovitis and bone destruction in RA multicenter studies.

Magnetic resonance findings in knee dislocation: pictorial essay

Magnetic resonance images depicting the range of soft-tissue and bony injuries associated with knee dislocation are presented. Those injuries that are less well described or more difficult to diagnose are emphasized.

Tests of the ratio rule in categorization

Many theories of learning and memory (e.g., connectionist, associative, rational, exemplar based) produce psychological magnitude terms as output (i.e., numbers representing the momentary level of some subjective property). Many theories assume that these numbers may be translated into choice probabilities via the ratio rule, also known as the choice axiom (Luce, 1959) or the constant-ratio rule (Clarke, 1957). We present two categorization experiments employing artificial, visual, prototype-structured stimuli constructed from 12 symbols positioned on a grid. The ratio rule is shown to be incorrect for these experiments, given the assumption that the magnitude terms for each category are univariate functions of the number of category-appropriate symbols contained in the presented stimulus. A connectionist winner-take-all model of categorical decision (Wills & McLaren, 1997) is shown to account for our data given the same assumption. The central feature underlying the success of this model is the assumption that categorical decisions are based on a Thurstonian choice process (Thurstone, 1927, Case V) whose noise distribution is not double exponential in form.

A 1-year follow-up study of dynamic magnetic resonance imaging in early rheumatoid arthritis reveals synovitis to be increased in shared epitope-positive patients and predictive of erosions at 1 year

OBJECTIVES

Dynamic magnetic resonance imaging (MRI) allows visualization of the synovial membrane and measurement of synovitis within the joint. A cohort of patients with early rheumatoid arthritis (RA) were studied using MRI of the dominant wrist and clinical assessments. Associations between synovitis and the shared epitope genotype (SE) were looked for and synovitis as a predictor of joint erosion was examined.

METHODS

Gadolinium-enhanced MRI scans of the dominant wrist were performed in 42 early RA patients at baseline (median disease duration = 4 months) and after 1 yr. Images were obtained at 42-s intervals over the first 6 min after gadolinium-diethylenetriamine pentaacetic acid injection using six cuts in the coronal plane, 2 mm apart. The site of maximal synovial enhancement was selected as the region of interest (ROI). The rate of enhancement (E-rate) was calculated and compared with synovitis scores from static MRI scans, clinical disease activity scores and HLA-DRB1*04/01 genotyping [sequence-specific primer polymerase chain reaction (SSP-PCR) and DNA sequencing].

RESULTS

Reproducibility of the E-rate measurement was assessed by re-evaluating 10 randomly selected scans in a blinded fashion. Intra-observer reliability was high with an intraclass correlation coefficient of 0.91, 95% confidence interval (CI) 0.65-0.97. The E-rate correlated strongly at baseline with the maximum level of synovial enhancement (E-max) (r = 0.88, P < 0.0001) and the static MRI synovitis score (r = 0.52, P = 0.0004). There was also a weaker but significant correlation between E-rate and the pain score (r = 0.29, P = 0.04). The E-rate fell from baseline to 1 yr (P = 0.02) concordant with clinical improvement after treatment with standard therapies. E-rate scores were higher in SE+ than SE - patients (F(1,25) = 5.19, P = 0.03) and were predictive of MRI erosions at 1 yr [chi-square = 5.0 (1 d.f.), P = 0.03]. The baseline C-reactive protein (CRP) was also predictive of MRI erosions at 1 yr to a similar degree [chi-square = 4.7 (1 d.f. ), P = 0.03] but the mean static synovitis score at baseline was the strongest predictor [chi-square = 9.2 (1 d.f.), P = 0.003].

CONCLUSIONS

These results show that dynamic MRI can be used to score synovitis objectively in early RA patients. Synovitis was greater in SE+ patients, suggesting an early genetic influence on joint inflammation, and was predictive for the development of erosions at 1 yr.

Magnetic resonance imaging of the wrist in early rheumatoid arthritis reveals progression of erosions despite clinical improvement

OBJECTIVES

To investigate the progression of joint damage in early rheumatoid arthritis (RA) using magnetic resonance imaging (MRI) of the wrist and determine whether this technique can be used to predict prognosis.

METHODS

An inception cohort of 42 early patients has been followed up prospectively for one year. Gadolinium enhanced MRI scans of the dominant wrist were obtained at baseline and one year and scored for synovitis, tendonitis, bone marrow oedema, and erosions. Plain radiographs were performed concurrently and scored for erosions. Patients were assessed clinically for disease activity and HLA-DRB1 genotyping was performed.

RESULTS

At one year, MRI erosions were found in 74% of patients (31 of 42) compared with 45% at baseline. Twelve patients (28.6%) had radiographic erosions at one year. The total MRI score and MRI erosion score increased significantly from baseline to one year despite falls in clinical measures of inflammation including erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and swollen joint count (p < 0.01 for all). Baseline findings that predicted carpal MRI erosions at one year included a total MRI score of 6 or greater (sensitivity: 93.3%, specificity 81.8%, positive predictive value 93.3%, p = 0.000007), MRI bone oedema (OR = 6.47, p < 0.001), MRI synovitis (OR = 2.14, p = 0.003), and pain score (p = 0.01). Radiological erosions at one year were predicted by a total MRI score at baseline of greater than 13 (OR = 12.4, p = 0.002), the presence of MRI erosions (OR = 11.6, p = 0.005), and the ESR (p = 0.02). If MRI erosions were absent at baseline and the total MRI score was low, radiological erosions were highly unlikely to develop by one year (negative predictive value 0.91 and 0.92 respectively). No association was found between the shared epitope and erosions on MRI (p = 0.4) or radiography (p = 1.0) at one year.

CONCLUSIONS

MRI scans of the dominant wrist are useful in predicting MRI and radiological erosions in early RA and may indicate the patients that should be managed aggressively. Discordance has been demonstrated between clinical improvement and progression of MRI erosion scores.

Pain and cognitive status in the institutionalized elderly: perceptions & interventions

The purposes of this study were to examine the relationship between: (1) nurses' ratings of pain and corresponding administration of pain medication to elderly long-term care residents, and (2) cognitive status of the elderly and pain medication orders/administration. Participants were 83 residents, 60 years of age and older, in two groups: cognitively impaired (n = 64), and cognitively intact (n = 19). For comparison purposes, 19 of the cognitively impaired subjects were matched on age and diagnosis to provide control for potentially painful conditions. A retrospective medication review of the resident's charts was conducted to compare medication orders and administration on analgesics that were scheduled and p.r.n. (given as needed). The pain ratings of 25 RNs using a visual analogue scale were correlated with pain medications given to the resident on the day of the rating. Results indicated that RNs' ratings of resident pain and the administration of pain medications were not significantly correlated. In addition, cognitively impaired residents were prescribed significantly less scheduled medication and received significantly less pain medication (either p.r.n. or scheduled) than the cognitively intact elderly. Implications for practice and research are discussed.

Magnetic resonance imaging of the wrist in early rheumatoid arthritis reveals a high prevalence of erosions at four months after symptom onset

OBJECTIVES

To evaluate the role of magnetic resonance imaging (MRI) of the wrist in detecting early joint damage in patients with rheumatoid arthritis (RA).

METHODS

MRI was performed on 42 patients with early RA (median symptom duration of four months). Scans were scored separately by two musculoskeletal radiologists using a newly devised scoring system, which was validated. MRI findings were compared with plain radiography, clinical measures, and HLA-DRB*01/04 genotyping.

RESULTS

Interobserver reliability for the overall MRI score was high (r = 0.81) as was intraobserver reliability (r = 0.94 for observer 1 and 0.81 for observer 2). There was more variation in scoring synovitis (interobserver reliability: r = 0.74). Erosions were detected in 45% of scans (19 of 42), compared with 15% of plain radiographs. The most common site for erosions was the capitate (39%), for synovitis the ulnar aspect of the radiocarpal joint, and for tendonitis, the extensor carpi ulnaris tendon. The total MRI score and MRI synovitis score correlated most significantly with C reactive protein (r = 0.40 and 0.42 respectively, p < 0.01). The MRI erosion score was highly correlated with MRI bone marrow oedema (r = 0.83) as well as the Ritchie score and disease activity score (r = 0.32, p < 0.05). HLA-DRB1*04 or *01 (shared epitope +ve) was found in 76% of patients; 84% of those with MRI erosions and 69% of those without (NS, p = 0.3).

CONCLUSIONS

A high proportion of RA patients develop MRI erosions very early in their disease, when plain radiography is frequently normal. MRI of the dominant wrist may identify those requiring early aggressive treatment.

Prevalence of Dientamoeba fragilis antibodies in children and recognition of a 39 kDa immunodominant protein antigen of the organism

Dientamoeba fragilis, a common intestinal protozoan parasite in Canada, has been associated with diarrhoea and abdominal pain in some patients. Seroprevalence of this organism has not been reported previously. In the present study sera from three symptomatic patients, 12 age- and sex-matched controls, and 189 randomly selected healthy individuals (age 6 months to 19 years) were tested for antibodies against Dientamoeba fragilis by an indirect immunofluorescence (IIF) assay. All three symptomatic patients infected with Dientamoeba fragilis had positive IIF titres of 80, and all 12 matched controls had positive titres ranging 20 to 160 (geometric mean titre 48). Of the 189 healthy children, 172 (91%) were positive at a serum dilution of 1:10 or higher. The specificity of the IIF assay was reinforced by immunoblotting 20 representative serum samples against Dientamoeba fragilis. In all 17 IIF-positive serum samples, a 39 kDa protein band of Dientamoeba fragilis was identified, the same band recognized by a mouse monoclonal antibody raised in our laboratory. Findings over a five-year period indicate that Dientamoeba fra-gilis was the most common protozoan, followed closely by Giardia lamblia and more distantly by Cryptosporidium parvum. The high seropositivity of 91% for Dientamoeba fragilis compares reasonably well with serologic data obtained by IIF and reported previously for Giardia lamblia (85.6%) and Cryptosporidium parvum (86%).

Evidence for a second cell cycle block at G2/M by p53

Wild type p53 can induce cell cycle arrest at specific points in the cell cycle, in particular G1/S, an ability lost by most p53 mutants. We have previously reported that p53 mutant genes can rescue REF52 cells from ras-induced growth arrest and that over expression of wild type p53 inhibits cell growth in these cells. In this paper we examined whether p53 can also induce cell cycle arrest at the G2/M boundary of the cell cycle. To accomplish this we used the REF52 cell line and the temperature sensitive p53val135 mutant allele. Cells were enriched in the late G1 and early S phases before the temperature shift. REF52 cells expressing mutant-p53val135 alone with an activated H-ras gene arrest primarily at the G1/S and G2/M parts of the cell cycle at the restrictive temperature, as determined by flow cytometry analysis. These results suggest that the anti-proliferative activity of p53 may be involved in regulation of the cell cycle at the G2/M restriction point as well as transit through G1/S and initiation of DNA synthesis.