during adolescence, when bone mineral mass accrual is a major determinant of peak bone mass [1][2][3][4][5][6][7][8][9]. It has been well-established that adult women and adolescent girls with AN differ in patterns of biochemical markers of bone turnover [1,2,7,8,10]. Women with AN show a decrease in bone formation and an increase in bone resorption markers, consistent with an uncoupling of bone turnover leading to impaired bone metabolism [7,8,10]. Adolescent girls with AN, on the other hand, have low turnover rates with decreases in bone formation and resorption markers [7,8,10,11,18,19,[21][22][23][24]. It has also been found that the receptor activator of Endokrynologia Polska

Introduction: Inflammation is supposed to be one of the factors contributing to decreased bone mineral density (BMD) in anorexia nervosa (AN). The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are simple and cost-effective inflammatory markers, well documented as indicators of postmenopausal osteoporosis. This study aimed to assess the relationships between these ratios and BMD in girls with AN. Material and methods:The electronic records of 73 girls hospitalized for AN were analysed retrospectively. The age range of the study group was 12.56-17.67 years. BMD was assessed by dual-energy X-ray absorptiometry (DXA) and expressed as Z-scores according to lumbar spine (s-BMD) and total body (TB-BMD) sites. NLR and PLR were calculated according to complete blood count results. Patients were divided into 2 subgroups with parallel analysesaccording to the TB-BMD criterion and the s-BMD criterion: normal (Z-score > -2.0, n = 63) and low s-BMD subgroup (Z-score ≤ -2.0, n = 10), and normal (Z-score > -2.0, n = 45) and low TB-BMD subgroup (Z-score ≤ -2.0, n = 28).Results: In the low s-BMD subgroup a tendency to an increase of mean NLR, PLR, and WBC values was observed. Respective BMD Z-score values correlated significantly and negatively with PLR in the low s-BMD (R = -0.892, p < 0.001) and normal TB-BMD (R = -0.451, p = 0.002) subgroups, while with NLR only in the normal TB-BMD subgroup (R = -0.685, p < 0.001). In the low s-BMD subgroup the PLR was shown to be a significant and independent predictor of s-BMD (β = -0.881, p < 0.001). The PLR contributed to 77.6% of the s-BMD Z-score variability (R 2 = 0.776, p < 0.001). In the normal TB-BMD subgroup, the PLR and NLR levels were significant and independent predictors of TB-BMD (β = -0.352, p = 0.004; β = -0.450, p = 0.001; β = -0.339, p = 0.005, respectively) and explained 44.4% of TB-BMD Z-score variability (R 2 = 0.444, p < 0.001). Conclusions:These results indicate that there might be a relationship between bone mass loss and inflammation expressed as NLR and PLR in adolescent girls suffering from AN. These connections seem to be dependent on the examined skeletal area. NLR and PLR, which are common indicators of morbidity and mortality in many malignancies and inflammatory chronic diseases, can also be useful in the evaluation of bone condition in adolescent females with AN. However, there is a need for further investigation in this field.

Adipose tissue is currently considered not only as an energy store but also as an organ of internal secretion. Numerous adipocytokines regulating a number of human body processes are important in many disease processes, including chronic kidney disease (CKD). Nowadays, the role of zinc a2-glycoprotein (ZAG) is being sought as a potential link between these two organs. ZAG, through its lipolytic effect, contributes to progressive malnutrition in patients undergoing dialysis, and this significantly increases their mortality. It seems that ZAG may be a new potential biomarker of kidney damage, and the specific pharmacotherapy will significantly reduce the progressive process of cachexia. (Endokrynol Pol 2019; 70 (2): 179-189)

Urticaria is a common pediatric dermatosis characterized by local swelling, pruritus, and skin redness. The primary lesions include wheals and/or angioedema. By definition, acute urticaria lasts up to 6 weeks and usually occurs as a single episode in life. Chronic urticaria lasts over 6 weeks and is uncommon. Urticaria is a heterogenous disease. The development of skin lesions depends on the action of mast cells and other cells of the immune system, and inflammation is common in all forms of urticaria. Autoimmune mechanisms and activation of coagulation and fibrinolysis also play an important role. The etiology usually remains unknown. Urticaria, especially its chronic form, contributes to a significant decrease in quality of life due to prolonged discomfort and the necessity of long-term and sometimes expensive treatment. This article presents an up-to-date review of the literature on the incidence, causes, diagnosis, treatment and prognosis of urticaria in children.

Serious renal involvement in systemic diseases is common and generally constitutes a pivotal prognostic factor, making those pathology frequently seen in nephrology departments. A recent study even states that, among different medical subspecialists, nephrologists deal with the most complex patients, in terms of comorbidities and other complexity markers [2]. From this somehow eclectic nephrologist's perspective, it seems important to be aware of and keep a high level of suspicion for rare, non-renal, but potentially devastating complications of systemic diseases, like the one highlighted in this c l i n i c a l c a s e : t h e s e c o n d a r y h e m o p h a g o c y t i c lymphohistiocytosis (HLH). When HLH complicates a