Spontaneous production of bone-resorbing lymphokines by B cells in patients with systemic lupus erythematosus

Examination of Risk Factors and Expression Patterns of Atypical Femoral Fractures Using the Japanese Adverse Drug Event Report Database: A Retrospective Pharmacovigilance Study

Atypical femoral fracture (AFF) is a rare complication related to the use of bisphosphonates (BPs). Herein, we analyzed the risk factors and onset patterns of AFF using the Japanese Adverse Drug Event Report database and reported the findings. First, the independent risk factors for AFF were gender (female), high body mass index, and medical history of osteoporosis, arthritis, and systemic lupus erythematosus (SLE). Drug-related risk factors for AFF included BPs (i.e., alendronic acid, ibandronic acid, etidronic acid, zoledronic acid, minodronic acid, risedronic acid), denosumab, prednisolone, lansoprazole, rabeprazole, exemestane, letrozole, eldecalcitol, and menatetrenone. Therefore, it appears that AFF is influenced by a combination of patient backgrounds and drugs, and that the risk of developing AFF is particularly high in patients with fragile bones (e.g., osteoporosis, arthritis, and SLE). Second, in the analysis of AFF onset patterns, the onset of AFF from BPs and denosumab took a long time (>1 year) to develop. Analysis using a Weibull distribution showed wear-out failure-type AFF onset for BPs and denosumab, and both osteoporosis and cancer patients with long-term administration of these drugs showed a tendency to have an increased risk of onset. AFF developed earlier in osteoporosis patients with long-term administration of BPs and denosumab than in cancer patients.

Prevalence and Risk Factors of Reduced Bone Mineral Density in Systemic Lupus Erythematosus Patients: A Meta-Analysis

Background

We aimed to conduct a meta-analysis concerning the frequency and risk factors of reduced bone mineral density (BMD) in systemic lupus erythematosus (SLE) with evidence from published studies.

Methods

A comprehensive literature search was conducted based on the EMBASE, Web of Science, PubMed, and Cochrane Library databases up to March 5th, 2017. Eligible studies reported any prevalence of reduced BMD in SLE patients. All risk factors with odds ratios or risk ratios associated with reduced BMD were extracted.

Results

71 reports with 33527 SLE patients were included. Low BMD, osteopenia, and osteoporosis at any site were presented, respectively, in 45%, 38%, and 13% of the SLE patients. The prevalence of osteoporosis increased with the advancing of age, while U-shaped associations between age and the prevalence of low BMD and osteopenia were found. Lumbar spine was indicated to have higher prevalence of osteoporosis. Age, disease duration, drugs use, and many other factors were identified as predictors of reduced BMD.

Conclusion

Low BMD, osteoporosis, and osteopenia appeared to be prevalent in patients with SLE. Risk factors of reduced BMD were various.

Pathogenic Inflammation and Its Therapeutic Targeting in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE, lupus) is a highly complex and heterogeneous autoimmune disease that most often afflicts women in their child-bearing years. It is characterized by circulating self-reactive antibodies that deposit in tissues, including skin, kidneys, and brain, and the ensuing inflammatory response can lead to irreparable tissue damage. Over many years, clinical trials in SLE have focused on agents that control B- and T-lymphocyte activation, and, with the single exception of an agent known as belimumab which targets the B-cell survival factor BAFF, they have been disappointing. At present, standard therapy for SLE with mild disease is the agent hydroxychloroquine. During disease flares, steroids are often used, while the more severe manifestations with major organ involvement warrant potent, broad-spectrum immunosuppression with cyclophosphamide or mycophenolate. Current treatments have severe and dose-limiting toxicities and thus a more specific therapy targeting a causative factor or signaling pathway would be greatly beneficial in SLE treatment. Moreover, the ability to control inflammation alongside B-cell activation may be a superior approach for disease control. There has been a recent focus on the innate immune system and associated inflammation, which has uncovered key players in driving the pathogenesis of SLE. Delineating some of these intricate inflammatory mechanisms has been possible with studies using spontaneous mouse mutants and genetically engineered mice. These strains, to varying degrees, exhibit hallmarks of the human disease and therefore have been utilized to model human SLE and to test new drugs. Developing a better understanding of the initiation and perpetuation of disease in SLE may uncover suitable novel targets for therapeutic intervention. Here, we discuss the involvement of inflammation in SLE disease pathogenesis, with a focus on several key proinflammatory cytokines and myeloid growth factors, and review the known outcomes or the potential for targeting these factors in SLE.

Risks factors for low bone mineral density in pre-menopausal Mexican women with systemic lupus erythematosus

The aim of this study was to determine the prevalence and risk factors for low bone mineral density (BMD) in women with systemic lupus erythematosus (SLE). A cross-sectional study was conducted among 100 pre-menopausal patients with SLE. Patients were evaluated using a questionnaire about the following variables: age, disease duration, disease activity, chronic disease damage, cumulative corticosteroid dose, and history of fracture. Lumbar spine and hip measurements of BMD were performed by dual absorptiometry. Univariate and multivariate statistical analyses were used to assess the relationship between risk factors and BMD. The mean age was 32.8 +/- 8.7 years, and the median duration of SLE was 73.2 +/- 65 months. The mean cumulative corticosteroid dose was 20.0 +/- 21.3 g. The mean BMD was 1.09 +/- .18 g/cm(2) in the lumbar spine and 1.0 +/- .14 g/cm(2) in the hip. Osteopenia was present in 40% of patients and osteoporosis in 5%. In the multiple regression analysis, low BMD in the lumbar spine was associated with chronic disease damage and low body mass index (BMI). Low BMD in the hip was associated with cumulative corticosteroid dose and low BMI. Chronic disease damage, low BMI, and cumulative corticosteroid dose are risks factors for low BMD in pre-menopausal SLE patients. Osteopenia was found in 40% of patients, while osteoporosis was found in only 5%.

Chronic pediatric inflammatory diseases: effects on bone

In children, chronic inflammatory diseases present a significant challenge to long-term skeletal health. These conditions are often associated with poor appetite and suboptimal overall nutrition, altered nutrient utilization, delayed puberty, inactivity, and reduced muscle mass, all of which can alter bone metabolism. In addition, bone cell activity is susceptible to the effects of the immune response that characterizes these diseases. Moreover, drugs used to treat these maladies, notably glucocorticoids, may have negative effects on bone formation and on linear growth in developing children. As a result, predicted peak bone mass may not be achieved, and fracture risk may be increased in the short term or in the future. Studies using primarily dual energy X-ray absorptiometry have documented that deficits in bone mass are common in these diseases. However, there are wide variations in the prevalence of low bone mass, largely due to differences in the characteristics of each study population. Recent studies provide insight into the pathogenesis of decreased bone mass in these conditions. In this paper we will provide an overview of the effects of chronic inflammatory conditions on bone mass in children. We will also present relevant data from adult patients, when pediatric data are scant or not available.

Resolution of SLE-related soft-tissue calcification following haematopoietic stem cell transplantation

BACKGROUND

Calciphylaxis and calcinosis can both cause severe morbidity and mortality in patients with systemic lupus erythematosus (SLE). Haematopoietic stem cell transplantation (HSCT) has been successfully used to treat patients with refractory SLE. It was hypothesized that in calciphylaxis and calcinosis, ongoing inflammatory activity contributes to the calcium deposition in the media of small arteries, as well as perivascular and periarticular tissues. We report three patients whose soft-tissue calcification syndromes dramatically resolved after undergoing HSCT.

METHODS

Three patients referred for refractory SLE underwent HSCT at a tertiary care medical center. SLE serologies and clinical features before and after HSCT were recorded.

RESULTS

Despite receiving >6 months of intravenous cyclophosphamide (CYC), three SLE patients showed signs of persistent lupus activity, including severe soft-tissue calcification. The first patient was on haemodialysis and developed severe calciphylaxis with large ulcers and tissue necrosis. The second patient had calcinosis, with palpable crystals extruding from ulcers. The third patient had calcinosis characterized by subcutaneous nodules and plaques. Because prior conventional therapies had failed, the three were treated with high-dose CYC, anti-thymocyte globulin and HSCT. They have been followed post-HSCT for 26-38 months, with excellent clinical responses, including sustained resolution of skin abnormalities.

CONCLUSIONS

The successful treatment of advanced calcium deposition by aggressive immune ablation underscores the contribution of SLE-mediated inflammation to soft-tissue calcification syndromes.

Bone status in juvenile systemic lupus erythematosus

Osteoporosis is a well-recognized major health problem in adult patients with systemic lupus erythematosus (SLE). Children and adolescents with SLE, however are at even higher risk of developing osteoporosis later in life, since they develop the disease before achieving peak bone mass, which serves as a 'bone bank' for the rest of life. There is still a paucity of studies on bone mass in pediatric SLE, but those studies available provide evidence of reduced bone mass in this age group. A frequency of osteopenia of 40% measured by dual energy X-ray absorptiometry at one or more skeletal sites has been reported, and the lumbar spine is most seriously affected. Peak bone mass seems to be lower in childhood-onset SLE patients compared to healthy controls, and there are no signs of catch-up of bone mass in young adult patients with a history of pediatric SLE. Glucocorticoid therapy has been found to have a major negative effect on bone mass in these patients, thus the importance of keeping corticosteroid doses down to the lowest possible dose whenever possible. Interestingly, studies of oral alendronate therapy in children with rheumatic childhood diseases have shown promising results with increases of 15-33% during one year of treatment with no major side effects reported. Finally, there is a hope that new biologic therapies, which are more specific and steroid-sparing, will also have a beneficial effect on bone health in SLE in the future.

Microarray profiling of lymphocytes in internal diseases with an altered immune response: potential and methodology

Recently it has become possible to investigate expression of all human genes with microarray technique. The authors provide arguments to consider peripheral white blood cells and in particular lymphocytes as a model for the investigation of pathophysiology of asthma, RA, and SLE diseases in which inflammation is a major component. Lymphocytes are an alternative to tissue biopsies that are most often difficult to collect systematically. Lymphocytes express more than 75% of the human genome, and, being an important part of the immune system, they play a central role in the pathogenesis of asthma, RA, and SLE. Here we review alterations of gene expression in lymphocytes and methodological aspects of the microarray technique in these diseases. Lymphocytic genes may become activated because of a general nonspecific versus disease-specific mechanism. The authors suppose that in these diseases microarray profiles of gene expression in lymphocytes can be disease specific, rather than inflammation specific. Some potentials and pitfalls of the array technologies are discussed. Optimal clinical designs aimed to identify disease-specific genes are proposed. Lymphocytes can be explored for research, diagnostic, and possible treatment purposes in these diseases, but their precise value should be clarified in future investigation.

Disease damage and low bone mineral density: an analysis of women with systemic lupus erythematosus ever and never receiving corticosteroids

OBJECTIVES

To evaluate the relationship between disease damage and bone mineral density (BMD) in women with systemic lupus erythematosus (SLE).

METHODS

A cross-sectional study was conducted among 307 women with SLE. Patients attended a single clinic visit that included an interview, physical examination, laboratory testing and BMD measurements (hip and/or lumbar spine). Women were stratified by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology cumulative disease damage index (SDI) > or =1 (Damage) vs SDI=0 (No Damage), and prior use of corticosteroids (CS), yielding four groups: (1) Damage/CS(+) (n=138), (2) Damage/CS(-) (n=23), (3) no Damage/CS(-) (n=100), and (4) no Damage/CS(-) (n=46).

RESULTS

Mean age at SLE diagnosis was 32.7 +/- 11.8 yr, 24.4% were African American, 65.0% were premenopausal, and mean SDI +/- S.D. was 1.3 +/- 1.8. In the unadjusted and adjusted models controlling for significant univariate risk factors for osteoporosis, the reference group (Group 1) had significantly lower mean BMD T-scores at the hip and lumbar spine than groups having no disease damage (Groups 3 and 4) independent of CS use status. Similar hip and lumbar spine mean BMD T-scores were observed in women with disease damage with and without CS exposure (Groups 1 and 2).

CONCLUSIONS

Women with SLE having disease damage and no CS use had BMD T-scores at the hip and lumbar spine similar to those of women with disease damage and prior CS use. These findings suggest an association between disease damage and lower BMD T-scores in women with SLE.

Frequency of osteopenia in children and young adults with childhood-onset systemic lupus erythematosus

OBJECTIVE

To determine the frequency of osteopenia in patients with childhood-onset systemic lupus erythematosus (SLE) compared with that in healthy matched controls, and to evaluate the relationship between disease-related variables and bone mineral mass.

METHODS

Bone mineral density (BMD) and bone mineral content (BMC) were measured in a cohort of 70 patients with childhood-onset SLE (mean +/- SD disease duration 10.8 +/- 8.3 years, mean +/- SD age 26.4 +/- 9.9 years) and 70 age- and sex-matched healthy controls. BMD and BMC of the femoral neck, lumbar spine, total body, and distal one-third of the radius were measured by dual x-ray absorptiometry. We investigated the relationship between BMC and the following disease variables: cumulative dose of corticosteroids, organ damage, current use of corticosteroids, use of cyclophosphamide, age at disease onset, and disease activity at the time of diagnosis. Biochemical markers of bone metabolism were also measured.

RESULTS

BMD values for the lumbar spine and femoral neck were significantly lower in patients than in healthy controls. The reduction in BMD of the lumbar spine was significantly greater than that of the total body. In multiple linear regression analyses, a higher cumulative corticosteroid dose was significantly associated with lower BMC of the lumbar spine and femoral neck. Decreased lumbar spine BMC was also related to male sex.

CONCLUSION

The frequency of osteopenia was higher in patients with childhood-onset SLE than in matched controls. The lumbar spine was the most seriously affected skeletal site, followed by the femoral neck. The cumulative dose of corticosteroids was shown to be an important explanatory variable for BMC values in the lumbar spine and femoral neck.

Osteoporosis in Systemic Lupus Erythematosus Mechanisms

Osteoporosis is a potentially preventable condition frequently encountered in patients who have systemic lupus erythematosus (SLE). Bone loss in SLE is heterogeneous and likely a multifactorial process involving both traditional and lupus-related risk factors. Recognizing potential contributors to bone loss in the SLE patient may allow for earlier detection of osteoporosis and optimize bone health. This article reviews the current epidemiologic information available on osteoporosis and fracture data in SLE and discusses evaluation and management strategies pertinent to patients who have lupus.

Bone mineral density of Brazilian girls with juvenile dermatomyositis

We measured bone mineral density (BMD) in girls with juvenile dermatomyositis (JDM) considering multiple factors in order to determine if it could be used as a predictor of reduction in bone mass. A cross-sectional study of lumbar spine BMD (L2-L4) was conducted on 10 girls aged 7-16 years with JDM. A group of 20 age-matched healthy girls was used as control. Lumbar spine BMD was measured by dual-energy X-ray absorptiometry. Weight, height and pubertal Tanner stage were determined in all patients and controls. Duration of disease and mean daily and cumulative steroid doses were calculated for all patients on the basis of their medical charts. JDM activity was determined on the basis of the presence of muscle weakness, cutaneous vasculitis and/or elevation of serum concentration of one or more skeletal muscle enzymes. Seven patients demonstrated osteopenia or osteoporosis. Lumbar BMD was significantly lower in the JDM patients than the age-matched healthy control girls (0.712 vs 0.878, respectively; Student t-test, P = 0.041). No significant correlation between BMD and age, height, Tanner stage, disease duration, corticosteroid use, or disease activity was observed in JDM girls, but a correlation was observed between BMD and weight (Pearson's correlation coefficient, r = 0.802). Patients with JDM may be at risk for a significant reduction in BMD that might contribute to further skeletal fragility. Our results suggest that reduced bone mass in JDM may be related to other intrinsic mechanisms in addition to steroid treatment and some aspects of the disease itself may contribute to this condition.

Risk factors for osteoporosis in female patients with systemic lupus erythematosus

In the last years it has been recognized that patients with systemic lupus erythematosus (SLE) are at high risk of osteoporosis (OP) and fractures, both occurring through disease-specific (chronic arthritis, reduced physical activity, induction of cytokines promoting bone resorption, renal impairment, endocrine factors) and nondisease-specific mechanisms (sunshine avoidance with consequent vitamin D deficiency, glucocorticoids, immunosuppressants and chronic anticoagulants). Regarding anticoagulants, subcutaneous heparin is crucial against the risk of recurrent thromboembolism or pregnancy loss, specifically in patients with SLE and anti-phospholipid syndrome (APS). Thus heparin-induced OP represents one of the hazards of this treatment, first because heparin must be used long-term and secondly because pregnancy and lactation themselves may predispose to OP and fractures. Current data suggest the use of prophylaxis with calcium and vitamin D in all patients treated with heparin during pregnancy. Nevertheless glucocorticoid-induced OP (GIOP) is considered the most serious risk factor for OP and fractures in SLE patients. All guidelines recommend general measures and supplementation with calcium and vitamin D in all patients. However when considering premenopausal patients, there is no generally recommended treatment. Bisphosphonates, which are considered the first choice therapy for the prevention and treatment of GIOP, should be used 'cautiously' in these patients. Therefore the potential risks and lack of efficacy data on fracture risk reduction in premenopausal patients must be weighed against their proven efficacy in postmenopausal patients.

Secondary osteoporosis: underlying disease and the risk for glucocorticoid-induced osteoporosis

BACKGROUND

Chronic diseases of many organ systems require long-term (>or=1 year) treatment with glucocorticoids. Owing to the catabolic activity of glucocorticoid therapy, osteoporosis is a potential complication.

OBJECTIVES

This review discusses glucocorticoid-induced bone loss and the factors, including underlying disease, that increase the risk for osteoporosis. Therapeutic options for the prevention and treatment of glucocorticoid-induced osteoporosis (GIO) also are reviewed.

METHODS

A review of the English-language literature was conducted using the MEDLINE database and proceedings from scientific meetings. Search terms including glucocorticoid-induced osteoporosis, bone loss, and fracture were used to refine the search, and preference was given to studies published after 1990.

RESULTS

Long-term glucocorticoid treatment causes bone loss that is most precipitous in the first 6 months. Patients treated with glucocorticoids have additional risk factors for bone loss and osteoporosis that are associated with their primary disease. Chronic diseases can cause changes in bone metabolism, leading to bone loss in addition to that induced by glucocorticoids alone. Bone loss can be minimized through proper nutrition, weight-bearing exercise, calcium and vitamin D supplementation, and, where indicated, bisphosphonate treatment. The American College of Rheumatology Ad Hoc Committee on Glucocorticoid-Induced Osteoporosis guidelines recommend bisphosphonates for minimizing bone loss and fracture risk in patients at risk for GIO. Risedronate is indicated for the prevention and treatment of GIO, and alendronate is indicated for its treatment. Both risedronate and alendronate increase bone mineral density in patients at risk for GIO. Risedronate significantly reduces the incidence of vertebral fractures after 1 year of treatment (P<0.05). The effectiveness and tolerability of the bisphosphonates have not been established in pregnant women or pediatric patients.

CONCLUSIONS

Men and women initiating long-term glucocorticoid treatment and those with GIO should be concomitantly treated with effective osteoporosis therapy to reduce fracture risk and counseled on preventive lifestyle changes.

Bone mineral density in juvenile systemic lupus erythematosus

We evaluated spine bone mineral density (BMD) in Brazilian children with juvenile systemic lupus erythematosus (JSLE) in order to detect potential predictors of reduction in bone mass. A cross-sectional study of BMD at the lumbar spine level (L2-L4) was conducted on 16 female JSLE patients aged 6-17 years. Thirty-two age-matched healthy girls were used as control. BMD at the lumbar spine was measured by dual-energy X-ray absorptiometry. Weight, height and pubertal Tanner stage were determined in patients and controls. Disease duration, mean daily steroid doses, mean cumulative steroid doses and JSLE activity measured by the systemic lupus erythematosus disease activity index (SLEDAI) were determined for all JSLE patients based on their medical charts. All parameters were used as potential determinant factors for bone loss. Lumbar BMD tended to be lower in the JSLE patients, however, this difference was not statistically significant (P = 0.10). No significant correlation was observed in JSLE girls between BMD and age, height, Tanner stage, disease duration, corticosteroid use or disease activity. We found a weak correlation between BMD and weight (r = 0.672). In the JSLE group we found no significant parameters to correlate with reduced bone mass. Disease activity and mean cumulative steroid doses were not related to BMD values. We did not observe reduced bone mass in female JSLE.

Expression of cytokine- and chemokine-related genes in peripheral blood mononuclear cells from lupus patients by cDNA array

Systemic lupus erythematosus (SLE) is characterized by diverse and complex immune abnormalities. In an effort to begin to characterize the full complexity of immune abnormalities, the expression pattern of 375 potentially relevant genes was analyzed using peripheral blood mononuclear cells (PBMC) from 21 SLE patients and 12 controls by cDNA arrays. When mean gene expression for patients was compared to controls, 50 genes were identified that exhibited more than 2.5-fold difference in expression level. By the Mann-Whitney U test, 20 genes were significantly different (P < 0.05) between patients and controls. Most of these genes have not been previously associated with SLE and belong to a variety of families such as TNF/death receptor, IL-1 cytokine family, and IL-8 and its receptors. Hierarchical clustering of samples and differentially expressed genes revealed that with few exceptions, patients clustered separately from controls. These results highlight the potential use of the microarray data in identifying genes associated with SLE, which could become candidate molecular markers or future therapeutic targets.

Osteoporosis in murine systemic lupus erythematosus--a laboratory model

The aim of this study was to assess the skeletal metabolism in a murine model of systemic lupus erythematosus (SLE). MRL/n and MRL/l mice (respectively representing a benign and a malignant form of the disease) were observed from 1.5 to 6.5 months of life. The monthly follow-up included: biochemical and histomorphometrical studies of the femoral bone, serum biochemistry, immunoglobulins and osteocalcin, and histological evaluation of the kidney tissue. The results showed a higher femoral weight (+11.5%), calcium (+4.4%) and protein bone content (+11.4%) and a significantly higher (+77%) phosphorus bone content in the MRL/n group; significantly lower (-48.9%) bone alkaline phosphatase enzymatic activity, lower bone alkaline/acid phosphatase enzymatic activities ratio (-40.8%) and lower (-38.4%) serum osteocalcin values in the MRL/l group (which might suggest reduced bone formation in these animals); markedly smaller trabecular bone volume (BV/TV) in the femoral head (-36.2%) and femoral neck (-39.8%), and smaller cortical and femoral areas in the mid-femoral shaft (-38.8% and -38.1% respectively) in the MRL/l group; higher serum immunoglobulins, increased serum blood urea nitrogen (BUN) and creatinine and a higher index of activity in the kidney histology in the MRL/l group, indicating increased activity of the disease in this substrain. The MRL mice, through their two substrains, may serve as a valuable laboratory animal model for study of the skeletal changes in SLE and of the influence of the disease activity on the skeletal metabolism.

Steroid-induced osteoporosis in systemic lupus erythematosus

The patient with SLE is at considerable risk of osteoporosis, because of the inflammatory disease itself, its consequences, and its treatments. Because of their extensive use, glucocorticoids are thought to be the most frequent cause of drug-related osteoporosis and may be responsible for much of the bone loss in lupus. This article focuses on the mechanisms of steroid-induced osteoporosis in SLE and outlines strategies for prevention and treatment.

Bone mineral density in systemic lupus erythematosus: comparison with rheumatoid arthritis and healthy controls

OBJECTIVES

To examine bone mineral density (BMD) frequency of osteoporosis and reduced bone mass in systemic lupus erythematosus (SLE), and compare the data of the SLE patients with matched rheumatoid arthritis (RA) patients and healthy controls. Secondly, to study possible correlations between BMD, demographic and disease variables in the SLE patients.

METHODS

Measures of BMD assessed by dual energy x ray absorptiometry were obtained from 75 SLE patients aged </= 70 years, 75 RA patients matched for age, sex and disease duration, and from 75 healthy controls matched for age, sex and geographical area. Disease activity and accumulated organ damage were assessed in the SLE patients.

RESULTS

The SLE patients had significantly lower BMD values at lumbar spine L2-L4 and hip, and higher frequency of osteoporosis at all sites of measurement compared with matched healthy controls. The matched SLE and RA patients had similar BMD, prevalence of osteoporosis and reduced bone mass. In the SLE patients BMD was more strongly correlated with accumulated organ damage than with markers of disease activity or duration. In multivariate analyses BMD was at all sites predicted by age and body mass, at lumbar spine also by the current corticosteroid dose.

CONCLUSION

The study showed reduced BMD in patients with SLE compared with matched healthy controls. Premenopausal women taking corticosteroids were especially affected. Furthermore, the BMD of matched SLE and RA patients was reduced to a similar extent.

Urinary excretion of the pyridinium cross-links of collagen in systemic lupus erythematosus

The aim of this study was to measure the urinary excretion of the pyridinium cross-links of collagen and to determine their usefulness as markers of reduced bone mineral density in systemic lupus erythematosus (SLE). All female SLE patients managed at a single centre were invited to participate in a cross-sectional study of urinary pyridinium cross-links excretion (HPLC), bone mineral density (DXA), and SLE-related variables. Ninety-one women with SLE were studied, 35 of whom were postmenopausal. Pyridinoline/Creatinine (Pyd/Cr) and deoxypyridinoline/Cr (Dpd/Cr) levels in postmenopausal women were significantly increased compared with premenopausal values (p = 0.010 and p = 0.004, respectively). Univariate linear regression analysis revealed a significant association of Dpd/Cr with reduced femoral neck and lumbar spine BMD (p = 0.001, p<0.001), and of Pyd/Cr with reduced femoral neck BMD (p = 0.020). In addition, the association of Pyd/Cr with reduced lumbar spine BMD approached significance (p = 0.055). Stepwise multiple linear regression analysis adjusting for other variables confirmed a significant association of Dpd/Cr with reduced lumbar spine BMD (p = 0.006), and a significant association of both Pyd/Cr and Dpd/Cr with postmenopausal status (p = 0.003, p<0.001). It was concluded that in this SLE population, the urinary excretion of Dpd/Cr was a useful marker of reduced BMD at the lumbar spine. Menopausal status was a major predictor of cross-links excretion in SLE.

Loss of bone mineral density in premenopausal women with systemic lupus erythematosus

OBJECTIVE

To evaluate bone mineral density (BMD) in premenopausal patients with systemic lupus erythematosus (SLE).

METHODS

We measured BMD by dual energy x ray absorptiometry at lumbar vertebrae L2-4 and at the right femoral neck in 74 premenopausal white patients (mean age 30.8 years) with SLE who were receiving glucocorticoid therapy, and in a control group.

RESULTS

The mean cumulative dose of prednisone was 32.5 (SD 28) g. The mean dose at the time of absorptiometry was 13.7 (6.9) mg. BMD was significantly reduced at the spine and at the femoral neck in SLE patients when compared with the control group: L2-4 = 0.943 (0.1) g/cm2 v 1.038 (0.1) g/cm2 (p < 0.001); femoral neck = 0.766 (0.09) g/cm2 v 0.864 (0.1) g/cm2 (p < 0.001). Nine patients (12.1%), but none of the control group, had a BMD less than the reference range.

CONCLUSION

BMD in premenopausal patients with SLE was less than that in a control group and less than the reference range of values defining the presence of osteoporosis in 12.1%. We did not find a relationship between BMD and either cumulative or baseline dose of corticosteroid therapy.

Cytokines in rheumatic diseases

IL-1 and related cytokines have multiple biologic activities relevant to the rheumatic diseases. In addition to mediating inflammatory and immune responses, these proteins regulate many aspects of connective tissue metabolism. The cytokines interact in complex cascades: because of this, and various technical reasons, the exact role of cytokines in the pathogenesis of rheumatic diseases remains uncertain. However, considerable experimental data suggest that the abnormal regulation of cytokines contributes to such siseases as inflammatory arthritis, systemic lupus erythematosus, scleroderma, and dermatomyositis. Animal models of these diseases have contributed to understanding the role of cytokines in pathogenesis. Furthermore, drugs useful in treating these diseases affect cytokine pathways; some cytokines, their antagonists, or related substances have been used therapeutically to treat rheumatic diseases. The therapeutic use of these agents will likely increase as knowledge about the role of cytokines in the pathogenesis of rheumatic diseases expands.