Enhanced tissue factor pathway inhibitor response as a defense mechanism against ongoing local microvascular events of Legg-Calve-Perthes disease

Neutrophil to lymphocyte ratio may be a predictive marker of poor prognosis in Legg-Calvé-Perthes disease

BACKGROUND

Legg-Calvé-Perthes disease (LCPD) is the idiopathic avascular necrosis of the femoral head in childhood. The pathologic changes seen in the femoral head are likely a result of vascular factors. Blood neutrophil to lymphocyte (N/L) ratio is a simple marker of subclinical inflammation. This study aims to to analyse the predictive ability of N/L ratio for the prognosis in LCPD patients.

METHODS

Patients who had been diagnosed as LCPD from 2008 to 2014 were investigated retrospectively and 40 LCPD patients (33 male and 7 female) and 25 healthy age and sex-matched children (controls) were included in the study. LCPD patients were divided into 2 groups according to expected prognosis (good prognosis expected Herring A and B patients as Group I and poor prognosis expected Herring B-C and C patients as Group II) and healthy children (control) were included in Group III. All the patients' hematological markers were analysed.

RESULTS

Mean age was 7.1 ± 2.0 years in group I (4.9-12 years), 8.3 ± 2.2 years (4-12.5 years) in group II and 7.8 ± 1.3 years (6-12 years) in group III. Mean values for Groups I, II and III for neutrophil to lymphocyte (N/L) ratio were 1.13 ± 0.65, 1.75 ± 0.95, 1.08 ± 0.37, respectively. The mean neutrophil to lymphocyte (N/L) ratio of Group II was higher than the other 2 groups (p = 0.003).

CONCLUSIONS

N/L ratio may give us information about the natural course of LCPD and may be used as independent predictor of prognosis in patients with LCPD.

Lateral shelf acetabuloplasty for severe Legg-Calvé-Perthes disease in patients older than 8 years: A mean eleven-year follow-up

The natural history of Legg-Calvé-Perthes disease (LCPD) in children older than 8 years is usually poor without treatment. The treatment goal is to prevent deformity and incongruity of the hip by achieving a stable spherical femoral head in a deep, congruent, sharp-edged acetabulum, with a good range of hip movement at skeletal maturity. Lateral shelf acetabuloplasty in LCPD can increase the coverage of the femoral head, benefiting the remodeling of the femoral head and acetabulum. The aim of this study was to evaluate the efficacy of lateral shelf acetabuloplasty for severe LCPD in patients older than 8 years.We evaluated 51 patients with severe LCPD who underwent shelf acetabuloplasty between 1994 and 2005. Clinical and radiological examinations were evaluated preoperatively and over a mean follow-up of 132.35 months (range 102-183 months). According to the Catterall classification, the LCPD was classified as grade II in 11 (21.6%) patients, grade III in 15 (29.4%), and grade IV in 25 (49.0%). According to the Herring classification, there were 12 (23.5%) patients in grade B, 24 (47.1%) in grade B/C, and 15 (29.4%) in grade C. The mean ages at the onset of signs and at surgery were 103.39 months and 110.78 months, respectively.By the end of follow-up, all patients had a normal passive range of hip movement without pain. The mean Iowa hip score was improved from 69.5 ± 7.28 to 91.6 ± 5.14 (P < 0.001). According to the Stulberg classification, 11 (21.6%) hips were classified as grade 1, 19 (37.3%) hips as grade 2, 14 (27.5%) hips as grade 3, and 7 (13.7%) hips as grade 4. The CE angle, Sharp angle, medial joint space ratio, epiphysis height ratio, and percentage of acetabular coverage were significantly improved by shelf acetabuloplasty (P < 0.001).We recommend shelf acetabuloplasty for severe LCPD in patients older than 8 years. The procedure yields a favorable clinical outcome and Stulberg outcome for the hip. Shelf acetabuloplasty can improve femoral head coverage and reduce subluxation of the hip, with a benefit to the biological remodeling of the femoral head within the acetabulum.

Endothelial nitric oxide synthase gene polymorphism is associated with Legg-Calvé-Perthes disease

The aim of this study was to assess the association of 27-bp variable number tandem repeat (VNTR) polymorphism in intron 4 and G894T polymorphism in exon 7 of the endothelial nitric oxide synthase (eNOS) gene with Legg-Calvé-Perthes disease (LCPD), and to provide a scientific basis for further research into the pathogenic mechanism. A total of 80 patients with LCPD and 100 healthy subjects were recruited in this case-control study. The 27-bp VNTR and G894T polymorphisms of the eNOS gene were genotyped using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism, respectively, followed by agarose gel electrophoresis and DNA sequencing. Allelic and genotypic frequencies were computed in the two groups and subjected to statistical analysis. For the 27-bp VNTR polymorphism, individuals with LCPD showed a higher frequency of the ab genotype [27.5 vs. 14%; odds ratio (OR), 2.33; 95% confidence interval (CI), 1.10-4.92; P=0.024]. For the G894T polymorphism, the LCPD case group showed a higher frequency of the heterozygous genotype GT than the healthy control group (35 vs. 17%; OR, 2.67; 95% CI, 1.33-5.36; P=0.005). The results indicate that these eNOS gene polymorphisms may be a risk factor for LCPD. The 27-bp VNTR polymorphism in intron 4 and G894T polymorphism in exon 7 may be involved in the etiology of LCPD.

Increased soluble selectins as a reflection of activated platelets and endothelium in Legg-Calve-Perthes disease

BACKGROUND AND AIM

Legg-Calve-Perthes disease (LCPD) is still an enigma. Hemostatic abnormalities have been indicated in the pathogenesis. We had previously demonstrated enhanced tissue factor pathway inhibitor response, increased global fibrinolytic capacity, and an increase in thrombomodulin in patients with LCPD compared with healthy individuals. These studies emphasized the role of vascular endothelium in pathogenesis of the LCPD. P-selectin is expressed on activated platelets and endothelial cells, and E-selectin is expressed on activated endothelial cells. The aim of this study was to assess circulating E-selectin and P-selectin levels in LCPD patients, which might reflect an endothelium activation and/or injury.

MATERIALS AND METHODS

The study included 85 pediatric patients. Group I consisted of 55 patients with LCPD and group II (control) consisted of 30 healthy children. Peripheral venous blood concentrations of E-selectin and P-selectin levels were measured with a commercially available assay.

RESULTS

Mean age was 8.41±2.73 years in group I and 8.83±2.92 years in group II. Both E-selectin and P-selectin levels were higher in LCPD patients in comparison with the age-matched controls. E-selectin was 54.92±18.84 pg/mL in group I, 45.54±15.31 pg/mL in group II and P-selectin was 46.40±20.35 pg/mL in group I, 36.92±9.84 pg/mL in group II (P=0.022 and P=0.019, respectively).

CONCLUSIONS

On the basis of our results, two important endothelium and platelet markers, E-selectin and P-selectin, are upregulated in LCPD. Our results suggested that activated platelets and possibly endothelial activation, as reflected by enhanced P-selectin/E-selectin kinetics, might contribute to the microvascular thrombosis and/or inflammation of LCPD.

The epidemiology and demographics of legg-calvé-perthes' disease

The etiology of Legg-Calvé-Perthes' disease (LCPD) is unknown. There are many insights however from epidemiologic/demographic information. A systematic medical literature review regarding LCPD was performed. The incidence ranges from 0.4/100,000 to 29.0/100,000 children <15 years of age. There is significant variability in incidence within racial groups and is frequently higher in lower socioeconomic classes. The typical age at presentation ranges from 4 to 8 years (average 6.5 years), except for children from the Indian subcontinent (average 9.5 years). There is a mild familial component. The children demonstrate impaired growth in height, skeletal age, and birth weight. This impaired growth coincides with an age appropriate reduced somatomedin A activity and decreased levels of IGF. LCPD can be associated with abnormalities in the coagulation cascade, including an increase in factor V Leiden mutation, low levels of protein C and/or S, and decreased antithrombin activity. There is decreased turnover in type I collagen and synthesis of type III collagen, as well as reduced levels of urinary glycosaminoglycans in the active phases of the disorder. Subtle abnormalities in the opposite hip and other minor/major congenital defects are reported. Children with LCPD are active and score abnormally in certain standardized psychological tests.

Serum prolidase activity and oxidative-antioxidative status in Legg-Calve-Perthes disease

We aimed to find out that whether collagen turnover is altered in the context of Legg-Calve-Perthes disease (LCPD) by evaluating serum prolidase activity. We also investigated the correlation between collagen turnover and oxidative-antioxidative status in LCPD. Plasma prolidase activity, total oxidant status (TOS), total antioxidant capacity, and oxidative stress index (OSI) were determined for 39 patients with LCPD and 40 healthy controls. Serum prolidase activity, TOS, and OSI were higher, but TAC was lower in patients with LCPD compared with controls. Prolidase activity was positively correlated with TOS and OSI levels. Serum prolidase activity is significantly associated with LCPD.

Perthes' disease and the search for genetic associations: collagen mutations, Gaucher's disease and thrombophilia

The role of heritable thrombophilic risk factors in the pathogenesis of the Perthes' disease is controversial. The clinical and radiological findings of Perthes' disease may be indistinguishable from those of Gaucher's disease, and the most common Jewish N370S Gaucher mutation is threefold greater in patients with Perthes' disease. Familial osteonecrosis of the femoral head is associated with variant mutations of collagen type II (COL2A1 mutations). We therefore studied the potential role of genetic thrombophilia and the Gaucher and COL2A1 mutations in children with Perthes' disease. Genomic DNA of 119 children with radiologically-confirmed Perthes' disease diagnosed between 1986 and 2005 was analysed for the thrombophilic polymorphisms Factor V Leiden, 677T-MTHFR and FIIG20210A. The results were compared with those of a group of 276 children without Perthes' disease. DNA was also analysed for the Gaucher mutations N370S, G insertion (84GG), L444P, Intron 2 (IVS2+1G>A) and R496H. Enzymic assays confirmed the Gaucher disease status. Collagen (COL2A1) mutations of the 12q13 gene were also analysed. The prevalence of thrombophilic markers was similar among the 119 patients with Perthes' disease and the 276 control subjects. The prevalence of the Gaucher mutation was consistent with Israeli population carriership data and did not confirm an earlier-claimed association with Perthes' disease. All 199 patients were negative for the studied COL2A1 mutations. We found no genetic association between Perthes' disease and either Gaucher's disease or COL2A1 mutations or increased genetic thrombophilia among our patients compared with the control group. A systematic review of case-control studies suggested that there was a positive association between Perthes' disease and Factor V Leiden. The impact of this association upon the disease, although not consistent across the studies, remains unclear.

Heritable thrombophilia-hypofibrinolysis and osteonecrosis of the femoral head

We hypothesized that inherited thrombophilia and hypofibrinolysis were risk factors for osteonecrosis of the femoral head. We compared measures of thrombophilia and hypofibrinolysis in referred new adult patients with idiopathic osteonecrosis (n = 71) or secondary osteonecrosis (n = 62) with the same measures in sex- and race-matched healthy control subjects. Heritable thrombophilic Factor VIII and hypofibrinolytic Lp(a) were more frequently high in the 71 patients with idiopathic osteonecrosis than in control subjects. High Factor VIII, Factor V Leiden heterozygosity, and resistance to activated protein C, all heritable thrombophilias, were more frequently present in the 62 patients with secondary osteonecrosis than in control subjects. Our data suggest inherited thrombophilia and hypofibrinolysis are risk factors for both idiopathic and secondary osteonecrosis of the head of the femur.

Legg-Calve-Perthes disease, venous and arterial thrombi, and the factor V Leiden mutation in a four-generation kindred

In a 4-generation kindred identified through a 12-year-old female proband with Legg-Calve-Perthes Disease (LCPD) who was found to be heterozygous for the G1691A factor V Leiden mutation (FV), our specific aim was to assess associations of FV with LCPD and with venous and arterial thrombotic events. Despite lethal thromboembolism in 3 family members at ages 21, 35, and 38, retinal artery thrombosis, and deep venous thrombosis, no family members had previously been studied for the FV mutation until kindred screening-genetic counseling was prompted by the discovery of the FV mutation in a child proband with LCPD.

METHODS

In a 4-generation kindred identified through a 12-year-old female proband with LCPD and found to be heterozygous for the FV mutation, we assessed the FV genotype and its association with thromboembolism in 14 of 16 living first- and second-degree relatives.

RESULTS

There was 3-generation vertical and horizontal transmission of heterozygosity for the FV mutation. Of 14 living first- and second-degree relatives, 10 were heterozygous for the FV mutation, including the proband's sister, mother, and maternal grandmother. Of the 14 living relatives, 2 had thrombotic events (retinal artery thrombosis and deep venous thrombosis of the leg). The proband's maternal great-grandfather had a lethal pulmonary embolus at age 35, as did her maternal great aunt at age 38, and a female third cousin at age 21.

CONCLUSIONS

In a large kindred identified by a child with LCPD who was found to have the FV mutation, FV heterozygosity was found in 3 generations of previously undiagnosed family members and was associated with venous and arterial thrombosis throughout the kindred. We suggest that FV mutation be studied in children with LCPD facilitate diagnosis and genetic counseling for thrombophilia in their parents, siblings, and other kindred members, and because the proband LCPD child with the FV mutation is at increased risk for other thromboembolic abnormalities as an adult.

LEVEL OF EVIDENCE

1.

Interruption of the blood supply of femoral head: an experimental study on the pathogenesis of Legg-Calve-Perthes Disease

INTRODUCTION

The etiology of LCPD still is not clear. Thrombosis has been accused in the pathogenesis of LCPD but it is not proven until now. The aim of this study is to evaluate the results of single episode of obstruction of blood supply to the femoral heads of dogs.

MATERIAL AND METHOD

Blood supply femoral heads of 45 dogs was interrupted with embolisation with gel foam. The radiologic appearances, macroscopic and microscopic specimes of the hips were evaluated and compared with the human specimens of 15 LCPD patients obtained at the time of femoral osteotomies.

RESULTS

After one infarct, we demonstrated changes in femoral heads of puppies showing close resemblance to the findings of LCPD in human.

CONCLUSION

Obstruction of the femoral head caused by single artificial emboli caused changes in the femoral head similar to LCPD. The cause of the obstruction is obscure, intravascular and/or extravascular pathologies need specific attention, further studies focusing especially on the coagulation system are needed.