Prothrombin Time and Coagulation Factor IX as Hemostatic Risk Markers for Legg- Calvé-Perthes Disease

Progress in understanding Legg-Calvé-Perthes disease etiology from a molecular and cellular biology perspective

Legg-Calvé-Perthes disease (LCPD) is a hip disease caused by ischemia of the femoral epiphysis in children, which occurs in children aged 4-8 years (mean 6.5 years), with a male-to-female ratio of about 4:1. The disease has been reported for more than 100 years, but its etiology has not been elucidated. In recent years, a considerable amount of research has been carried out on the etiology of the disease, and the development of the disease is believed to involve a variety of molecular biological alterations, such as the COL2A1 mutation, which may be one of the causes of necrotic collapses of the epiphyseal cartilage matrix in LCPD. Tissue factor V Leiden mutation and insulin-like growth factor (IGF-1) abnormalities have also been reported in LCPD, but most theories need further confirmation. The in-depth study of LCPD cell biology has facilitated the suggestion regarding structural and/or functional abnormalities of microvascular endothelial cells in LCPD. This conjecture is supported by epidemiological and clinical evidence. Abnormal activation of osteoclasts, ischemic damage to epiphyseal cartilage, and activation of the bone marrow immune system all play important roles in the onset and progression of the disease. In this paper, we review the previous basic studies on LCPD and give an overview from the molecular biology and cell biology perspectives.

Bone Remodeling and Bone Structural Genes in Legg-Calvé-Perthes Disease: The OPG rs2073618 and IL-6 rs1800795 Are Associated with High Risk in Mexican Patients

Legg-Calve-Perthes disease (LCPD) is an idiopathic avascular necrosis of the pediatric femoral head. Bone remodeling and bone structural genes have the potential to contribute to the progression of LCPD when there is disequilibrium between bone resorption and bone formation. A case-control study was performed to search for associations of several common polymorphisms in the genes Receptor Activator for Nuclear Factor κappa B (RANK), Receptor Activator for Nuclear Factor κappa B Ligand (RANKL), osteoprotegerin (OPG), interleukin (IL)-6, and type 1 collagen (COL1A1) with LCPD susceptibility in Mexican children. A total of 23 children with LCPD and 46 healthy controls were genotyped for seven polymorphisms (rs3018362, rs12585014, rs2073618, rs1800795, rs1800796, rs1800012, and rs2586498) in the RANK, RANKL, OPG, IL-6, and COL1A1 genes by real-time polymerase chain reaction with TaqMan probes. The variant allele (C) of IL-6 rs1800795 was associated with increased risk of LCPD (odds ratio [OR]: 3.8, 95% confidence interval [CI]: [1.08-13.54], p = 0.033), adjusting data by body mass index (BMI) and coagulation factor V (FV), the association with increased risk remained (OR: 4.9, 95% CI: [1.14-21.04], p = 0.025). The OPG polymorphism rs2073618, specifically GC-GG carriers, was associated with a more than fourfold increased risk of developing LCPD (OR: 4.34, 95% CI: [1.04-18.12], p = 0.033) when data were adjusted by BMI-FV. There was no significant association between RANK rs3018362, RANKL rs12585014, IL-6 rs1800796, COL1A1 rs1800012, and rs2586498 polymorphisms and LCPD in a sample of Mexican children. The rs1800975 and rs2037618 polymorphisms in the IL-6 and OPG genes, respectively, are informative markers of increased risk of LCPD in Mexican children.

Gene expression profiling of peripheral blood in patients with steroid-induced osteonecrosis of the femoral head

Aim: Steroid-induced osteonecrosis of the femoral head (SONFH) is a severe complication following glucocorticoid therapy. This study aimed to identify the differential mRNA expression and investigate the molecular mechanisms of SONFH. Materials & methods: RNA sequencing was performed in eight SONFH patients, five non-SONFH patients and five healthy individuals. Results: A total of 1555, 3997 and 5276 differentially expressed mRNAs existed between the following combinations: SONFH versus non-SONFH, SONFH versus healthy subjects and non-SONFH versus healthy subjects. Increased ISM1 expression might contribute to a high risk of SONFH through antiangiogenesis. Decreased FOLR3 expression might affect the metabolism of homocysteine, leading to avascular necrosis of the femoral head. KCNJ2, which plays a pivotal role in regulating bone development, was also deregulated. Conclusion: ISM1, FOLR3 and KCNJ2 might be related to the occurrence of SONFH.

[Legg-Calvé-Perthes disease]

BACKGROUND

Legg-Calvé-Perthes disease (LCPD) is an important cause of limping and/or hip pain in preadolescent children.

OBJECTIVE

Pathogenesis and epidemiology of LCPD, classification of disease stages, quantitative femoral head involvement and prognosis based on X‑ray images and magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Summary and discussion of the basic research and recommendations.

RESULTS

Boys between 3 and 10 years of age are mostly affected. The etiology of the femoral head ischemia is still unknown. Commonly used classifications are the stages of disease according to Waldenström and the extent of the femoral head involvement according to Catterall. Head at risk signs are used for early prognosis, and after completion of growth Stulberg's end stages are applied for long-term prognosis.

CONCLUSION

Based on X‑ray images and MRI, different classifications can be used for an assessment of progression and prognosis of LCPD. This systematic approach is essential to identify cases that require surgical treatment and to avoid complications such as early onset osteoarthritis of the hip.