Cortical thinning and progressive cortical porosity in female patients with systemic lupus erythematosus on long-term glucocorticoids: a 2-year case-control study.

UNLABELLED: In this study, we characterized longitudinal changes of volumetric bone mineral density and cortical and trabecular microstructure at the distal radius using HR-pQCT in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. Cortical thinning and increased cortical porosity are the major features of longitudinal microstructural deterioration in SLE patients. INTRODUCTION: The study aims to characterize longitudinal changes of volumetric bone mineral density (vBMD) and bone microstructure at distal radius in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. METHODS: This 2-year case-control study consisted of 166 premenopausal subjects (75 SLE patients and 91 controls) and 79 postmenopausal subjects (44 SLE patients and 35 controls). We obtained areal BMD (aBMD) by dual-energy X-ray absorptiometry at multiple skeletal sites and indices of vBMD and microstructure at distal radius by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline, 12 and 24 months. RESULTS: In either premenopausal or postmenopausal subjects, changes in aBMD did not differ between patients and controls except that decrease in aBMD at total hip at 24 months in premenopausal patients was significantly higher. In premenopausal subjects, decrease in cortical area (-0.51 vs. -0.06 %, p = 0.039) and thickness (-0.63 vs. 0.02 %, p = 0.031) and increase in cortical porosity (21.7 vs. 7.16 %, p = 0.030) over study period were significantly larger in patients after adjustment of age and body mass index. Decreased in trabecular vBMD was significantly less (-0.63 vs. -2.32 %, p = 0.001) with trabecular microstructure better maintained in patients. In postmenopausal subjects, decrease in cortical vBMD (-2.66 vs. -1.56 %, p = 0.039) and increase in cortical porosity (41.6 vs. 16.3 %, p = 0.021) were significantly higher in patients, and there was no group-wise difference in change of trabecular microstructure. CONCLUSION: Longitudinal microstructural deterioration in SLE is characterized by cortical thinning and increased cortical porosity. Cortical bone is an important source of bone loss in SLE patients on glucocorticoids.

SLE disease per se contributes to deterioration in bone mineral density, microstructure and bone strength.

OBJECTIVE: The objective of this report is to assess the effect of systemic lupus erythematosus (SLE) disease itself on deterioration of bone mineral density (BMD), microstructure and bone strength. METHOD: Thirty age-matched SLE patients on long-term glucocorticoids (GC) (SLE/GC), 30 SLE patients without GC (SLE/non-GC) and 60 healthy controls were examined. Areal BMD (aBMD) was measured by dual-energy X-ray absorptiometry. Bone geometry, volumetric BMD (vBMD), and architectural parameters at the nondominant distal radius were assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT). Bone strength was estimated by HR-pQCT-based micro-finite element analysis. RESULTS: Adjusted for menopausal status and adjusted calcium level, when compared with controls, SLE/non-GC patients had significantly lower aBMD at femoral neck and total hip, and diminished radial total vBMD, cortical area, vBMD and thickness, respectively, by 8.3%, 8%, 2.7% and 9.2%, as well as significant compromised bone strength (stiffness, failure load and apparent modulus) by 8.3%, 9.1% and 9.5%, respectively. Similar alterations were also found in SLE/GC patients when compared to controls. In the premenopausal subgroup analysis, when compared with controls, total hip aBMD and radial cortical area were significantly lower in SLE/non-GC patients, and cortical area and thickness were significantly deficit in SLE/GC patients. However, no significant difference in any bone variables was present between SLE/GC and SLE/non-GC patients in the entire cohort or in the premenopausal subgroup. CONCLUSION: SLE disease per se contributes to the deterioration in bone density, cortical microstructure and bone strength. This might help to explain the considerably higher fracture risk seen in SLE patients.

Alterations of bone geometry, density, microarchitecture, and biomechanical properties in systemic lupus erythematosus on long-term glucocorticoid: a case-control study using HR-pQCT.

UNLABELLED: Compared to controls, HR-pQCT at distal radius of SLE patients on chronic glucocorticoid (SLE/GC) revealed reduced bone area, vBMD, deteriorated microarchitecture, and unevenly distributed stresses limited to cortical bone. Despite similar trabecular quality, whole bone strength decreased in patients. These alterations may partly explain high fracture rates in SLE/GC. INTRODUCTION: To assess bone geometric, densitometric, microarchitectural, and biomechanical properties in patients with systemic lupus erythematosus (SLE) on long-term glucocorticoid (GC) (SLE/GC) as compared with healthy controls. METHODS: A total of 180 female SLE patients and 180 healthy controls were in this cross-sectional study to assess areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) and microfinite element analysis (µFEA) was performed at distal radius. RESULTS: In addition to significantly lower aBMD at femoral neck, total hip and lumbar spine, cortical area, average volumetric BMD (vBMD) and cortical vBMD also significantly reduced by 5.3, 5.7, to 1.9 % in SLE patients, respectively. Deteriorations of cortical microarchitecture were pronounced in patients, with 6.3 % reduction in cortical thickness and 13.6 % higher in cortical porosity. Local stresses were more unevenly distributed through cortical bone in patients. SLE/GC patients had decreased whole bone stiffness, estimated failure load, and apparent modulus. Parameters related to trabecular bone density and microarchitecture were comparable between patients and controls. CONCLUSION: In SLE/GC patients, despite a reduction in bone area, vBMD and deteriorated microarchitecture and unevenly distributed stresses limited to the cortical compartment, whole bone strength decreased. HR-pQCT and µFEA were promising in elucidating the potential underlying pathophysiology of bone loss and propensity to fracture in SLE/GC and provide us additional information about alterations of bone quality which might better predict fracture risk beyond aBMD in SLE/GC.

Risk of tuberculosis in patients with rheumatoid arthritis in Hong Kong--the role of TNF blockers in an area of high tuberculosis burden.

OBJECTIVES: To elucidate the incidence rate and relative risk of tuberculosis (TB) in patients with rheumatoid arthritis (RA) compared to the general population in Hong Kong between 2004 and 2008, and to assess whether this risk is associated with exposure to tumour necrosis factor (TNF) blockers after adjusting for other known risk factors. METHODS: We reviewed all the medical records of RA patients to determine the standardised incidence ratio (SIR) of TB in RA patients. Independent explanatory variables associated with active TB in RA were ascertained using the Cox regression model. RESULTS: A total of 2441 RA patients followed at the 5 centres were recruited. The mean age at the start of follow up was 56±14 years. The median follow-up duration was 6,616 and 185 patient-years for the TNF naive and TNF treated groups, respectively. Compared to age- and sex-matched population controls, the SIR of active TB in RA was significantly increased (SIR for TNF naïve RA: 2.35, 95% CI 1.17-4.67, p=0.013, SIR for TNF treated RA: 34.92, 95% CI 8.89-137.20, p<0.001). Independent explanatory variables associated with an increase risk of active TB included older age at study entry (RR 1.05, p=0.013) a past history of pulmonary TB (RR 5.48, p=0.001), extra-pulmonary TB (RR 16.45, p<0.001), Felty's syndrome (RR 43.84, p=0.005), prednisolone>10mg daily (RR 4.44, p=0.009) and the use of TNF blockers (RR 12.48, p<0.001). CONCLUSIONS: Exposure to TNF blockers remained to be an independent risk factor for TB in RA after adjusting for other known risk factors.

Involvement, satisfaction and unmet health care needs in patients with psoriatic arthritis.

OBJECTIVE: To examine the involvement in care, participation in medical decision, satisfaction of health care and unmet needs in patients with PsA. To explore factors related to involvement and satisfaction with care. METHODS: One hundred and five patients with PsA attending four regional hospital rheumatology outpatient clinics were invited and consented to self-administer questionnaires, including socio-demographic data, quality of life with SF-12, involvement in medical decision, satisfaction with care and unmet health care needs. RESULTS: The overall perceived knowledge of disease was moderate. Good disease knowledge and good physical functioning were positively associated with involvement in care. Age, sex and pain scores were not associated with involvement in multivariate analysis. A low score in at least one question on involvement was the single independent negative predictor for satisfaction with health care. Only a minority (9%) was actively participating in medical decision-making. Among non-participants, 61.5% expressed the wish to participate. In aspects of education of disease, advice for exercise, psychological support and social support, respectively, 68.3, 73.3, 29.3 and 41.6% of the patients expressed unmet needs. CONCLUSION: Low involvement is negatively associated with satisfaction with health care in PsA. Good knowledge of disease and good physical functioning is positively associated with involvement. The current study supports patient education as an important factor associated with involvement of and satisfaction with care in PsA patients. Such patients have a high desire for information and numerous unmet health care needs. There is a need for improvement in the delivery of care to patients with PsA.

Impact of illness and variables associated with functional impairment in Chinese patients with psoriatic arthritis.

OBJECTIVES: To assess the impact of disease and functional outcomes in Chinese patients with psoriatic arthritis (PsA) and to identify variables associated with poor functional outcomes. METHODS: A cross sectional study performed in 80 consecutive patients with PsA from a single center. Functional outcomes were assessed by the Health Assessment Questionnaire (HAQ) and the Bath Ankylosing Spondylitis Functional Index (BASFI). Clinical variables included social-demographic characteristics and clinical features. Linear regression analyses were performed to identify variables associated with functional impairment. RESULTS: Thirty-six men and 44 women with mean (+/-SD) age and duration of arthritis of 48.6 (+/-13.0) and 10.2 (+/-6.9) years were studied. One-third reported PsA related unemployment and change in job nature. Another third experienced a reduction of income due to PsA. The median (IQR) HAQ and BASFI were 0.44 (1.09) and 2.1 (4.38). These functional scores correlated highly with each other and with the patient's perception of health, but correlated only moderately or poorly with other disease activity variables. Multivariate analysis identified higher damaged joint count, poorer patients' perception of health, poor socioeconomic factor and higher CRP as factors associated with higher HAQ. Higher back pain score; higher CRP, higher damaged joint count and poor socioeconomic factor were associated with BASFI. CONCLUSION: PsA in Chinese subjects has had significant social-economic impact. Joint damage was found to be associated with functional impairment.

Cardiovascular risk profile of patients with psoriatic arthritis compared to controls--the role of inflammation.

OBJECTIVE: To examine the distribution of traditional and novel risk factors of cardiovascular disease (CVD) in patients with PsA compared with healthy controls. METHODS: We compared risk factors for CVD between 102 consecutive PsA patients and 82 controls, adjusting for BMI. We also assessed the role of inflammation on the CVD risk factor by using a BMI and high-sensitivity CRP (hsCRP)-adjusted model. RESULTS: The BMI of PsA patients were significantly higher than healthy controls. After adjusting for the BMI, PsA patients still have a higher prevalence of diabetes mellitus (DM) [odds ratio (OR) 9.27, 95% CI 2.09, 41.09) and hypertension (OR 3.37, 95% CI 1.68, 6.72), but a lower prevalence of low high density lipoprotein (HDL) cholesterol (OR 0.16, 95% CI 0.07, 0.41). PsA patients have significantly increased systolic and diastolic blood pressures, insulin resistance and inflammatory markers (hsCRP and white cell count) compared to controls. PsA patients have higher HDL cholesterol and apolipoprotein (Apo) A1 levels; and lower total cholesterol (TC) and low density lipoprotein cholesterol levels; and a lower TC/HDL ratio. However, the Apo B level (P < 0.05), and the Apo B/Apo A1 ratio (P = 0.07) were higher in PsA patients. Further adjustment for hsCRP level rendered the differences in the prevalence of hypertension and DM; the TC, and sugar levels; and white cell count non-significant between the two groups; while the differences in other parameters remained significant. CONCLUSION: These data support the hypothesis that PsA may be associated with obesity, hypertension, dyslipidaemia and insulin resistance because of the shared inflammatory pathway.

Psoriatic arthritis as a distinct disease entity.

Psoriatic arthritis (PsA) is a chronic systemic inflammatory disease characterized by joint inflammation associated with cutaneous psoriasis. For many years, the amount of attention directed to PsA had been less than that for various other arthropathies. With the advances in understanding its pathogensis, it is now recognized as a distinct disease entity with characteristic features. Psoriatic arthritis has a greater tendency towards asymmetric oligoarticular involvement, distal interphalangeal involvement and spondylitis. Associated features such as enthesitis and dactylitis are more common. Specific radiological features include ankylosis and bone resorption. With the availability of potent new therapeutic agents for psoriasis and PsA, interest in research and clinical care for these conditions has been reinvigorated. Anti-TNF therapy has achieved encouraging efficacy in both the joints and skin disease, improving function and quality of life and inhibiting radiological progression measured in patients with PsA and psoriasis. Biologic agents may have the potential in addressing the unmet medical need in patients with PsA.

Urine protein-to-creatinine ratio in an untimed urine collection is a reliable measure of proteinuria in lupus nephritis.

OBJECTIVE: To evaluate the accuracy of urine protein-to-creatinine (P/C) ratio in an untimed urine specimen as compared with 24 h total protein excretion for measurement of proteinuria in patients with lupus nephritis. METHODS: Proteinuria in patients with lupus nephritis was assessed by 24 h total protein excretion and spot urine P/C ratio. Correlation and limits of agreement between the two methods were evaluated. The discriminant cutoff values for spot urine P/C ratio in predicting 24 h protein 'threshold' excretion of > or =0.3, > or =0.5, > or =1.0 and > or =3.5 g/day were determined using receiver operating characteristic curves. RESULTS: A total of 165 samples were available for assessment with 21.8% excluded due to inadequate collection. A strong correlation (r = 0.91, P < 0.0001) was found between spot urine P/C ratio and 24 h urine protein excretion. Bland-Altman plot showed the two tests had acceptable limits of agreement in low level of protein excretion (-0.86 to +0.92 g/day when protein excretion was <2.0 g/day). The limits became wider as the protein excretion increased. The spot urine P/C ratios of 0.45 (sensitivity 0.92; specificity 0.88), 0.7 (0.92; 0.89) and 1.84 (1.0; 0.86) mg/mg reliably predicted 24 h urine total protein equivalent 'thresholds' at > or =0.5, 1.0 and 3.5 g/day. CONCLUSION: This study supports the recommendation of using spot urine P/C ratio in screening and monitoring proteinuria in patients with lupus nephritis. However, in assessing the exact amount of proteinuria, the urine P/C ratio may have unacceptably wide limits of agreement in high protein excretion range.

Estimation of glomerular filtration rate in patients with systemic lupus erythematosus.

The objective of this study was to compare the limit of agreement of creatinine clearance (CrCl) estimated by different equations with the CrCl measured by 24-hour urine collection in Hong Kong Chinese patients with systemic lupus erythematosus (SLE). Forty-three SLE patients with mild to moderate renal impairment (serum creatinine concentration >80 micromol/L to <300 micromol/L for females; and >106 micromol/L to <300 micromol/L for males) and not requiring renal replacement therapy were assessed. The estimated clearances were calculated by the Cockcroft-Gault (CG) equation, the Modification of Diet in Renal Disease (MDRD) study equation and the abbreviated MDRD (aMDRD) study equation. The estimated clearances were compared against the measured CrCl by 24-hour urine collection for their limit of agreement. Forty-three patients with mean (+/-SD) age of 41.6 (+/-8.4) years were assessed. As compared to the measured CrCl in patients with SLE, the clearances by CG equation, MDRD and aMDRD equations predicted a mean difference of -0.8% (95% confidence interval, -43.9-42.3%); -8.6% (95% CI, -24.3-7.2%) and -4.7% (95% CI, -21.4-12%), respectively. There is a tendency for the MDRD and aMDRD study equations to underestimate CrCl. The MDRD and aMDRD study equations have better predictive value than the CG equation.

Disseminated cutaneous infection with Mycobacterium chelonae mimicking panniculitis in a patient with dermatomyositis.

We report a case of disseminated cutaneous Mycobacterium chelonae infection. A patient with dermatomyositis associated with malignancy presented with features of panniculitis. This was later confirmed to be cutaneous Mycobacterium chelonae infection. Disseminated cutaneous Mycobacterium chelonae infection and panniculitis are reviewed.

Failure of neutrophils to recover their ability to produce superoxide after stunning by a conventional, acidic, lactate-based peritoneal dialysis solution.

Exposure of human neutrophils to conventional, acidic, lactate-based peritoneal dialysis solutions for 5 minutes results in a depression of superoxide generation. In spite of restoration of extracellular pH to 7.4, these stunned cells failed to recover their ability to generate the anion after a period of an hour.

Heterotopic ossification presenting as acute arthritis.

We describe a patient with acute myeloblastic leukemia in remission who developed painful, swollen knees 6 weeks after being ventilated for acute respiratory distress syndrome. Synovial fluid analysis was nondiagnostic and initial radiographs of his knees were normal. Repeat radiographs 5 weeks later showed periarticular calcification and the diagnosis of heterotopic ossification was made. Heterotopic ossification should be part of the differential diagnosis of acute arthritis in critically ill patients.