Abstract
Background and Aims
Avascular necrosis of bone (AVN) is an important complication of systemic lupus erythematosus (SLE) and often causes serious physical disability. The aim of this study was to investigate the risk factors for symptomatic avascular necrosis of bone (AVN) in lupus nephritis (LN) patients.
Method
The records of 374 patients (43 males, 331 females) with kidney biopsy-proven LN were reviewed retrospectively. Symptomatic AVN cases were defined as those with at least one diagnosis of AVN. The patients with LN who did not have AVN were evaluated as a control group. To determine risk factors for AVN, clinical, laboratory and therapeutic variables were analyzed by logistic regression.
Results
Symptomatic AVN was present in 17 patients (4 males, 13 females, mean age of 27,4±6,7 years). Among the 17 patients, 28 joints presented AVN. 12 occurred in hips (2 bilateral), 6-in ankles, 4-in knees, 3-in shoulders and 1- in lumbar spine. In 9 patients AVN involved 2 or more joints. 14 patients were on steroids at the time of presentation of AVN. 2 patients were not on CS and 1 patient did not has documentation of steroid use. Meta-analysis demonstrates a significant increased risk of AVN in patients with high disease activity and class IV LN (p<0,005). LN patients with AVN showed an earlier onset age (p<0,05) and received significantly higher total cumulative corticosteroid dose. AVN was not significantly associated with use of immunosuppressive agents. Serositis, coagulation disorders, vasculitis, cigarette smoking were higher incidence in male with LN and AVN. Raynaud‘s phenomenon, autoimmune thyroiditis, arthritis, Sjögren’s syndrome, IgM anticardiolipin antibodies, antiphospholipid syndrome, Cushingoid body habitus were higher incidence in female with LN and AVN.
Conclusion
Many risk factors have been involved in the development of AVN in LN patients. AVN is prevalent in class IV LN and in younger patients. Since asymptomatic osteonecrosis may remain undetected, its true prevalence could be much higher than we reported. Multifocal lesions involving more than three anatomical sites are unusual. Corticosteroids are the principal risk factor, although some cases of AVN occur in relatively steroid naïve patients. Early detection of AVN is important because the prognosis depends of the stage and location of the lesion. An individual risk assessment for AVN development should be made prior to and during treatment for LN, especially in patients high dose corticosteroids.
Avascular necrosis of bone while on alendronate: report of a case: Authors' Reply
