ABSTRACT
Chronic pruritus is one of the most common symptoms of dermatological diseases. It may occur in the course of other disorders, such as kidney disease. Chronic kidney disease-associated pruritus (CKD-aP) most often affects people with end-stage renal disease. The etiology of this condition is still not fully understood, but researchers are currently focusing on a thorough analysis of the association between disturbed opioid balance and increased neuronal signaling leading to pruritus. The aim of this study is to assess the concentration of endogenous opioids in dialysis patients with and without pruritus and in the control group, and to determine the correlation between the concentration of these substances and the occurrence and severity of itching. The study involved 126 dialysis patients and 50 healthy controls. Patients were divided into groups with pruritus (n = 62) and without pruritus (n = 64). The severity of pruritus was assessed using the NRS scale. The concentration of endogenous opioids was determined using the ELISA. The concentration of met-enkephalin was higher in the group of patients with pruritus compared to the control group. Moreover, significantly lower levels of ß-endorphin and dynorphin A were observed in the group of dialysis patients compared to the control group. In addition, a statistically significant difference was seen between the ß-endorphin concentration in the group of dialysis patients with pruritus compared to the group without pruritus. The ratio of ß-endorphin/dynorphin A concentrations was significantly lower in the group of patients with pruritus compared to patients without pruritus and the control group. No correlations were found between serum level of studied opioids and the severity of pruritus. The concentrations of the studied opioids did not correlate with the severity of pruritus. Observed opioid imbalance may affect the occurrence of CKD-aP in dialysis patients, but a thorough understanding of the mechanism of action of these substances in the sensation of pruritus is necessary to assess the possibility of finding a new therapeutic target.
ABSTRACT
Chronic kidney disease-associated pruritus (CKD-aP) is a bothersome condition that occurs in patients with advanced chronic kidney disease (CKD) and severely reduces their quality of life. Recently, much research has focused on the search for markers that are involved in the pathogenesis of CKD-aP and may become a therapeutic target. One of the suggested hypotheses is the increased activation of sensory neurons by molecules such as neurotrophins (NTs). An increased serum concentration of NTs has been demonstrated in pruritic patients, which may suggest their involvement in the pathogenesis of itch. The purpose of this study is to assess the serum concentration of neurotrophin-4 (NT-4) and brain-derived neurotrophic factor (BDNF) in hemodialysis patients. The study enrolled 126 patients undergoing dialysis. Participants were divided into 2 groups: with and without CKD-aP. NRS scale was used to evaluate itch severity. Serum levels of NT-4 and BDNF have been assessed using ELISA. The results showed a significantly higher level of NT-4 in the group with pruritus. No significant difference was reported in the serum level of BDNF between the two groups of patients. There was also no correlation between serum NT-4 nor BDNF levels and the severity of pruritus. In summary, NT-4 may play an important role in the pathophysiology of pruritus in dialysis patients. More research is needed to understand the exact mechanism by which NTs influence the pathogenesis of CKD-aP.
ABSTRACT
SARS-CoV-2 shows a high affinity for the ACE-2 receptor, present on the epithelial cells of the upper and lower respiratory tract, within the intestine, kidneys, heart, testes, biliary epithelium, and-where it is particularly challenging-on vascular endothelial cells. Liver involvement is a rare manifestation of COVID-19. MATERIAL AND METHODS: We reviewed 450 patients admitted due to the fact of SARS-CoV-2 infection (COVID-19) including 88 with liver injury. Based on medical history and previous laboratory test results, we excluded cases of underlying liver disease. The analysis involved a clinical course of COVID-19 in patients without underlying liver disease as well as the type and course of liver injury. RESULTS: Signs and symptoms of liver injury were present in 20% of patients, mostly presenting as a mixed-type pattern of injury with less common cases of standalone hepatocellular (parenchymal) or cholestatic injury. The liver injury symptoms resolved at the end of inpatient treatment in 20% of cases. Sixteen patients died with no cases where liver injury would be deemed a cause of death. CONCLUSIONS: (1) Liver injury secondary to COVID-19 was mild, and in in 20%, the signs and symptoms of liver injury resolved by the end of hospitalization. (2) It seems that liver injury in patients with COVID-19 was not associated with a higher risk of mortality. (3) The underlying mechanism of liver injury as well as its sequelae are not fully known. Therefore, caution and further monitoring are advised, especially in patients whose liver function tests have not returned to normal values.
