Serum klotho concentrations inversely correlate with the severity of nailfold capillaroscopic patterns in patients with systemic sclerosis.

Klotho is a transmembrane and soluble glycoprotein that governs vascular integrity. Previous studies have demonstrated reduced serum klotho concentrations in patients with systemic sclerosis (SSc), and it is known that klotho deficiency can impair the healing of digital ulcers related to microvessel damage. The aim of this study was to evaluate the association between serum klotho levels and nailfold capillaroscopic abnormalities in SSc patients. We retrospectively enrolled 54 consecutive patients with SSc diagnosed on the basis of the 2013 EULAR/ACR criteria [11 with diffuse SSc; 47 females; median age 68.0 years (IQ 18); median disease duration 11.0 years (IQ 7)]. Serum klotho concentrations were determined by means of an enzyme-linked immunosorbent assay. On the basis of the 2000 classification of Cutolo et al., 14 patients had normal nailfold capillaroscopic findings, 8 had an early scleroderma pattern, 21 an active scleroderma pattern, and 11 a late scleroderma pattern. The median serum klotho concentration was 0.29 ng/mL (IQ 1). Regression analysis of variation showed an inverse correlation between serum klotho concentrations and the severity of the capillaroscopic pattern (p=0.02; t -2.2284), which was not influenced by concomitant treatment. Logistic regression did not reveal any significant association between the risk of developing digital ulcers and nailfold capillaroscopic patterns, serum klotho levels, or concomitant medications. The presence of avascular areas significantly correlated with calcinosis (p=0.006). In line with previous studies, our findings confirm that klotho plays a role in preventing microvascular damage detected with nailfold capillaroscopy.

The role of klotho in systemic sclerosis.

The aim was to evaluate the role of klotho in the pathogenesis of systemic sclerosis (SSc), through the measurement of its serum concentration in SSc patients compared to healthy controls, and to assess the association with cutaneous and visceral involvement. Blood samples obtained from both SSc patients and healthy controls were analysed by an ELISA assay for the detection of human klotho. SSc patients were globally evaluated for disease activity and assessed through the modified Rodnan's Skin Score, Medsger's scale, pulmonary function tests, 2D-echocardiography, nailfold capillaroscopy and laboratory tests. Our cohort consisted of 69 SSc patients (61 females, mean age 64.5±12.5 years, median disease duration 9.0 (IQR 8) years) and 77 healthy controls (28 females, mean age 49.7±10.2 years). In the group of SSc patients, 19 (27.5%) suffered from a diffuse form of SSc. All patients were receiving IV prostanoids, and some of them were concomitantly treated with immunosuppressive drugs (prednisone, hydroxychloroquine, mofetil mycophenolate, methotrexate, cyclosporin A and azathioprine). The median serum concentration of klotho was significantly lower in patients compared to controls (0.23 ng/mL vs 0.60 ng/mL; p<0.001). However, Spearman's test showed no significant association between klotho serum levels and disease activity, concerning either clinical, laboratory or instrumental findings. Our data show a significant deficit of klotho in SSc patients although any significant association was detected between klotho serum concentration and the clinical, laboratory or instrumental features of the disease. However, due to the limits of the study, further investigations are required.

[Athlete's heart: frontier between physiology and pathology]. / Coeur d'athlète: frontière entre physiologie et pathologie.

Athletes often exhibit structural and electrical cardiac adaptations that are influenced by several factors including sporting discipline, gender and ethnicity. These changes are considered physiological and reversible in most cases. However, recent data indicate that atrial and right ventricular remodeling in athletes may represent pathological changes leading to arrhythmias. Sudden cardiac death in athletes is a rare but dramatic event. The differential diagnosis between the athlete's heart and heart diseases that are potential etiologies of sudden cardiac death, such as hypertrophic cardiomyopathy, may be challenging. New recommendations about electrocardiogram interpretation in athletes may help to improve prevention strategies.