Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa protein that is secreted mostly by immune cells such as neutrophils, macrophages, and dendritic cells. Its production is stimulated in response to inflammation. The concentrations of NGAL can be measured in plasma, urine, and biological fluids such as peritoneal effluent. NGAL is known mainly as a biomarker of acute kidney injury and is released after tubular damage and during renal regeneration processes. NGAL is also elevated in chronic kidney disease and dialysis patients. It may play a role as a predictor of the progression of renal function decreases with complications and mortality due to kidney failure. NGAL is also useful in the diagnostic processes of cardiovascular diseases. It is highly expressed in injured heart tissue and atherosclerostic plaque; its serum concentrations correlate with the severity of heart failure and coronary artery disease. NGAL increases inflammatory states and its levels rise in arterial hypertension, obesity, diabetes, and metabolic complications such as insulin resistance, and is also involved in carcinogenesis. In this review, we present the current knowledge on NGAL and its involvement in different pathologies, especially its role in renal and cardiovascular diseases.

Melatonin is a neurohormone that is mainly secreted by the pineal gland. It coordinates the work of the superior biological clock and consequently affects many processes in the human body. Disorders of the waking and sleeping period result in nervous system imbalance and generate metabolic and endocrine derangements. The purpose of this review is to provide information regarding the potential benefits of melatonin use, particularly in kidney diseases. The impact on the cardiovascular system, diabetes, and homeostasis causes melatonin to be indirectly connected to kidney function and quality of life in people with chronic kidney disease. Moreover, there are numerous reports showing that melatonin plays a role as an antioxidant, free radical scavenger, and cytoprotective agent. This means that the supplementation of melatonin can be helpful in almost every type of kidney injury because inflammation, apoptosis, and oxidative stress occur, regardless of the mechanism. The administration of melatonin has a renoprotective effect and inhibits the progression of complications connected to renal failure. It is very important that exogenous melatonin supplementation is well tolerated and that the number of side effects caused by this type of treatment is low.

Hypercalcemia is one of the most common ionic disorders. It is diagnosed when the serum calcium concentration is greater than 10.5 mg/dL. While mainly associated with primary hyperparathyroidism and malignancy, it can also be caused by multiple derangements. Almost every part of the body can be affected by excess calcium. Hypercalcemia might be very dangerous and even lethal. We report a rare trigger of increased serum calcium level - synthol intramuscular injections. A 60-year-old man who suffered from general weakness, weight loss and acute kidney injury, which were associated with unidentified hypercalcemia, was under review for proper diagnosis. We excluded endocrine disorders, malignancies, sarcoidosis, iatrogenic causes, which were defined as medication- related. Patient history, physical examination, blood chemistry, 24-hour urine collection, computed tomography and endoscopy were performed. Finally, the biopsy of muscle explained the source of the increased serum calcium concentrations. Hypercalcemia is a common disorder that has a wide range of triggers. Synthol intramuscular injections are among the causes of elevated serum calcium levels. It is important to make proper and quick diagnoses and begin therapy. Unfortunately, surgical resection of the synthol seems to be the only reasonable option for hypercalcemia treatment.

Tegoroczny Zjazd Polskiego Towarzystwa Nefrologicznego odbył się w Katowicach w dniach 12–14 czerwca. Podczas wydarzenia przedstawiono aktualne stanowisko Towarzystwa dotyczące diagnostyki oraz nowoczesnego leczenia chorób nerek. Omówiono możliwości farmakologicznej nefroprotekcji w przewlekłej chorobie nerek. Kilka wykładów poświęcono nowoczesnym metodom leczenia hiperkaliemii. Zaprezentowano także zalecenia dotyczące stosowania dożylnych środków kontrastowych w grupie pacjentów z upośledzoną funkcją nerek. Ponadto omówiono możliwości terapeutyczne pozwalające zmniejszyć ryzyko chorób układu sercowo-naczyniowego w przewlekłej chorobie nerek. Istotną część Zjazdu stanowiły wykłady dotyczące chorób nerek uwarunkowanych genetycznie oraz nowoczesnych metod leczenia nefropatii IgA. Warsztaty umożliwiły zapoznanie się z ciekawymi przypadkami klinicznymi oraz zaktualizowanie wiedzy na temat korzyści płynących ze stosowania diety ubogobiałkowej u pacjentów z przewlekłą chorobą nerek.

Background: Osteocalcin (OC) is a protein synthesized by osteoblasts and is involved in bone formation. OC also participates in the regulation of metabolic processes. Serum OC concentrations rise with kidney function decrease. The aim of this study was to evaluate the associations between serum OC concentrations and laboratory parameters reflecting metabolic, nutritional and hormonal status, as well as anthropometric and body composition measurements in patients with eGFR (estimated Glomerular Filtration Rate) < 60 mL/min/1.73 m². Methods: The study sample consisted of 144 men: 98 patients with eGFR < 60 mL/min/1.73 m² (the study group) and 46 individuals with eGFR ≥ 60 mL/min/1.73 m² (the control group). Body composition parameters were estimated with the use of bioimpedance spectroscopy (BIS). Laboratory measurements, including serum OC were performed. Results: In univariable regression analysis we observed a negative association between OC and parameters related to adipose tissue and a positive relationship with variables reflecting fluid overload in the study group. Serum laboratory measurements showed that plasma OC was positively associated with serum creatinine and parathyroid hormone (PTH) and negatively with plasma hemoglobin, insulin, vitamin D and HOMA-IR (Homeostatic Model Assessment of Insulin Resistance). Multivariable backward regression analysis showed a negative association between OC and fat tissue index (FTI) and a positive relationship between OC and relative overhydration (Rel OH) and PTH in men with eGFR < 60 mL/min/1.73 m². Conclusions: Our results suggest that in men with CKD (Chronic Kidney Disease) and eGFR < 60 mL/min/1.73 m² not receiving dialysis, serum OC may be associated with metabolic, nutritional, and hormonal disturbances. The observed association between OC and parameters indicative of fluid overload also suggests a potential role of serum OC as a marker of overhydration in this population.