Osteonecrosis in Primary Antiphospholipid Syndrome is Associated with Previous Glucocorticoid Use and Thrombocytopenia

Differential risk of autoimmune disorders in non-traumatic osteonecrosis: clue to pathogenesis

INTRODUCTION

Non-traumatic osteonecrosis is a frequent complication in patients with autoimmune disorders, though its prevalence varies markedly depending upon the type of disorder. Understanding the causes of this difference can help uncover the underlying pathophysiology of osteonecrosis and guide the development of effective preventive and therapeutic strategies.

AREAS COVERED

In this perspective study, we reviewed available databases, including PubMed, Cochrane Library, Scopus, and Web of Science, to explore why the risk of osteonecrosis varies among different autoimmune disorders. Is this variation primarily due to the disease's pathophysiology, the use of medications such as corticosteroids, or a combination of both? If both factors are involved, what is the extent of each contribution in this context?

EXPERT OPINION

Non-traumatic osteonecrosis is often induced by an interaction between disease pathophysiology and corticosteroid use. In patients with different autoimmune disorders but an identical history of corticosteroid use, the risk of osteonecrosis is influenced by how the underlying pathophysiology compromises bone health. In autoimmune disorders with multiple adverse effects on bone, such as SLE (systemic lupus erythematosus), there is a much higher risk of osteonecrosis compared to disorders with minimal impact on bone health, such as celiac disease and MS (multiple sclerosis).

Avascular Necrosis of the Femoral Head in Patients with Antiphospholipid Syndrome: A Case Series

Background/Objectives: Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombosis or obstetric complications and the laboratory detection of antiphospholipid antibodies. Although vascular thrombosis is the main manifestation of the disease, other rarer complications have also been described. Avascular necrosis (AN) is considered a rare manifestation of APS. The aim of our case series is to study patients with APS and AN. Methods: A retrospective study was performed on 80 patients diagnosed with APS. Results: AN was observed in 3 patients out of 80 diagnosed with APS. AN of the femoral head was observed in all cases. Case (1): A 54-year-old woman presented due to multiple ischemic infarctions in the brain, as detected in magnetic resonance imaging of the brain, Raynaud's phenomenon, and AN of the femoral head. In laboratory testing, a prolongation of activated partial thromboplastin time was recorded. A heterozygous mutation was also found in the gene MTHFR C677T, and the patients was positive for lupus anticoagulant (LA). The patient was given clopidogrel and acenocoumarol. Case (2): A 52-year-old man was diagnosed with APS, based on the clinical presentation (stroke) and positivity for LA and anti-β2GPI (anti-β2 glycoprotein I antibody). In his medical history, episodes of vertigo and an episode of AN of the femoral head 2 years ago were described. Case (3): A woman aged 43 years presented due to AN of the femoral head. Due to suspected APS, immunological testing was performed, and positivity for LA and IgM anticardiolipin antibodies was detected. She was treated with acenocoumarol. Conclusions: AN is a rare clinical manifestation of APS, which may precede the diagnosis of APS for many years.

Epidemiology of antiphospholipid syndrome: macro- and microvascular manifestations

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombotic and non-thrombotic macro- and microvascular manifestations and pregnancy complications in the setting of persistent antiphospholipid antibodies (aPL), namely anticardiolipin antibodies, anti-β2 glycoprotein-I antibodies and lupus anticoagulant. Four decades after its first description, APS prevalence and incidence are still not completely understood due to the limited number of well-designed, population-based multi-ethnic studies. Furthermore, despite decades of efforts to standardise aPL immunoassays, considerable intraassay and interlaboratory variances in aPL measures still exist. Large multicentre APS cohorts have shown a 10-year survival of ∼91% and the presence of catastrophic APS occurs in about 1% of the entire population, associated with a 50% mortality rate. Clinically, any organ can be affected in the context of large, medium or small vessel (artery and/or vein) thrombosis. Macrovascular thrombosis is the hallmark of the disease and veins are more frequently affected than arteries. Deep vein thrombosis/pulmonary embolism thromboembolic disease is the most common APS manifestation, while stroke and transient ischaemic attack are the most frequent arterial thrombosis events. Myocardial infarction can also occur and contributes to increased mortality in APS. A minority of patients present with thrombosis affecting the intraabdominal organs, including the liver, spleen, small and large bowel, and the kidneys. Microvascular thrombosis, including APS nephropathy, chronic skin ulcers and livedoid vasculopathy represent a diagnostic challenge requiring histologic confirmation. In this narrative review we summarize the available evidence on APS epidemiology, focusing on the description of the prevalence of macro- and microvascular manifestations of the disease.