Neurotrophin-4 and Brain-Derived Neurotrophic Factor Serum Levels in Renal Transplant Recipients with Chronic Pruritus

INTRODUCTION

Chronic pruritus (CP) is a common symptom defined as a sensation that provokes the desire to scratch and which lasts for at least 6 weeks. CP remains a problem for up to 21.3% of renal transplant recipients (RTRs). Our research aimed to establish the possible association between serum levels of neurotrophin-4 (NT-4) and brain-derived neurotrophic factor (BDNF) and the presence and intensity of CP in RTR.

METHODS

The study was performed on a group of 129 RTRs, who were divided according to the presence or absence of pruritus in the previous 3 days. The assessment of pruritus was performed with the use of a numeric rating scale (NRS), 4-Item Itch Questionnaire (4IIQ), and Itchy Quality of Life (Itchy QoL). A total of 129 blood samples with a volume of 9 ml were drawn from RTRs during the monthly routine control. Serum levels (pg/mL) of NT-4 and BDNF were measured by the ELISA.

RESULTS

Pruritic RTRs have statistically significantly higher serum concentrations of NT-4 serum level compared to non-pruritic RTRs (229.17 ± 143.86 pg/mL and 153.08 ± 78.19 pg/mL [p = 0.024], respectively). Moreover, a statistically significant difference between pruritic and non-pruritic RTRs with healthy controls was shown (p < 0.001 and p < 0.001, respectively). Although there was a numerically higher serum concentration of BDNF in pruritic RTRs (32.18 ± 7.31 pg/mL vs. 31.58 ± 10.84 pg/mL), the difference did not reach statistical significance. No statistically significant difference was also seen in BDNF serum levels between RTRs and healthy controls. Furthermore, there was a statistically significant, positive correlation between serum concentration of NT-4 and NRS score (p = 0.008, r = 0.357).

CONCLUSIONS

The results indicate higher NT-4 serum concentration in RTRs with pruritus compared to RTRs without pruritus. Furthermore, the study revealed a statistically significant, positive correlation between the serum concentration of NT-4 and NRS score.

Endogenous Opioid Imbalance as a Potential Factor Involved in the Pathogenesis of Chronic Kidney Disease-Associated Pruritus in Dialysis Patients

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 β-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 β-endorphin concentration in the group of dialysis patients with pruritus compared to the group without pruritus. The ratio of β-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.

Serum Level of Protein-Bound Uraemic Toxins in Haemodialysis Patients with Chronic Kidney Disease-Associated Pruritus: Myths and Facts

Recent studies place great importance on Protein-Bound Uraemic Toxins (PBUT) in the context of etiopathogenesis of chronic kidney disease-associated pruritus (CKD-aP). This study aimed to investigate the possible contribution of free and total Indoxyl Sulfate (IS) and p-Cresol Sulfate (PCS) to the cause of CKD-aP. Group A included 64 patients on maintenance haemodialysis (HD) with CKD-aP. Group B included 62 patients on maintenance HD that did not report CKD-aP, and group C included 50 healthy controls. Pruritus severity was assessed using a Numerical Rating Scale (NRS). Moreover, other tools like UP-Dial, ItchyQoL, and the 4-Item Itch Questionnaire evaluating CKD-aP were completed by the patients. The serum levels of free and total IS and PCS concentrations were measured using the Ultra Performance Liquid Chromatography System. No significant difference in the serum level of free and total IS, or PCS, was observed between the patients who reported CKD-aP and those without pruritus. Moreover, there was no correlation between serum IS or PCS levels and the severity of the itch. Our study does not support earlier findings about higher levels of IS and PCS in patients reporting CKD-aP. Further studies will be needed to investigate these discrepancies as well as to understand the cause of CKD-aP.

Elevated Level of Serum Neurotrophin-4, but Not of Brain-Derived Neurotrophic Factor, in Patients with Chronic Kidney Disease-Associated Pruritus

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.

Chitinase-3-like Protein 1 (YKL-40): A New Biomarker of Inflamma-tion in Pyoderma Gangrenosum

Pyoderma gangrenosum (PG) is a rare, neutrophil-ic dermatosis with unclear aetiopathology, considered as an autoinflammatory disease, associated with other immune-mediated disorders. Chitinase-3-like protein 1 (YKL-40) is an inflammatory biomarker secreted by a wide variety of cells, including neutrophils. To evaluate YKL-40 serum level in relation to clinicopathological data, 48 patients with PG and 40 healthy controls were enrolled in the study. Skin lesions were measured to calculate the affected area. Inflammatory parameters (C-reactive protein, white blood cell count with neutrophils) were determined from blood samples. YKL-40 and IL-6 levels were measured in serum by enzyme-linked immunosorbent assay. YKL-40 serum level was significantly higher in patients with PG than in controls (58.4 vs 36.4 ng/ml, respectively; p < 0.00001). The positive correlation between YKL-40 level and IL-6 level was observed (r=0.48, p = 0.0006) along with a trend towards significance of relationship between YKL-40 level and C-reactive protein (r=0.28, p = 0.052). YKL-40 can be considered a valuable biomarker of inflammation in PG.

Immunosuppression as a Hallmark of Critical COVID-19: Prospective Study

The dysregulation of both the innate and adaptive responses to SARS-CoV-2 have an impact on the course of COVID-19, and play a role in the clinical outcome of the disease. Here, we performed a comprehensive analysis of peripheral blood lymphocyte subpopulations in 82 patients with COVID-19, including 31 patients with a critical course of the disease. In COVID-19 patients who required hospitalization we analyzed T cell subsets, including Treg cells, as well as TCRα/β and γ/δ, NK cells, and B cells, during the first two weeks after admission to hospital due to the SARS-CoV-2 infection, with marked reductions in leukocytes subpopulations, especially in critically ill COVID-19 patients. We showed decreased levels of Th, Ts cells, Treg cells (both naïve and induced), TCRα/β and γ/δ cells, as well as CD16+CD56+NK cells in ICU compared to non-ICU COVID-19 patients. We observed impaired function of T and NK cells in critically ill COVID-19 patients with extremely low levels of secreted cytokines. We found that the IL-2/INFγ ratio was the strongest indicator of a critical course of COVID-19, and was associated with fatal outcomes. Our findings showed markedly impaired innate and adaptive responses in critically ill COVID-19 patients, and suggest that the immunosuppressive state in the case of a critical course of SARS-CoV-2 infection might reflect subsequent clinical deterioration and predict a fatal outcome.

Serum Concentration and Skin Expression of S100A7 (Psoriasin) in Patients Suffering from Hidradenitis Suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease. An important role of innate immune dysregulation in the pathogenesis of HS has been highlighted. S100A7 (psoriasin) is an innate, antimicrobial protein that exerts proinflammatory and chemotactic action.

OBJECTIVES

The objective of the study was to investigate serum concentrations of S100A7 in individuals with HS as compared to healthy controls. Further, we evaluated the expression of S100A7 in lesional HS skin as compared to perilesional (clinically uninvolved) HS skin and normal skin.

METHODS

Serum concentrations of S100A7 were evaluated with a commercially available ELISA kit. The expression of S100A7 in the skin was assessed using qRT-PCR and immunofluorescence staining.

RESULTS

We found increased expression of S100A7 in lesional HS skin as compared to perilesional HS skin (p = 0.0017). The expression of S100A7 in lesional HS skin was positively associated with serum C-reactive protein concentration and the severity of disease according to Hurley staging. The serum concentration of S100A7 in individuals with HS was decreased as compared to healthy controls and patients with psoriasis.

CONCLUSIONS

Upregulated in lesional HS skin, S100A7 may enhance the inflammatory process and contribute to the HS pathogenesis.

Chitinase-3-like protein 1 (YKL-40) is a biomarker of severity of joint involvement in psoriatic arthritis

INTRODUCTION

Psoriasis is an inflammatory disease of a complex pathogenesis and arthritis is one of its most common complications. The biological role of chitinase-3-like protein 1 remains unknown. It is suggested that this protein takes part in processes such as proliferation, inflammation and tissue remodelling.

AIM

To determine whether YKL-40 can be a useful biomarker in psoriatic arthritis.

MATERIAL AND METHODS

The study was performed on 42 patients with psoriatic arthritis: 28 men and 14 women, aged from 24 to 71 years. All patients met the diagnostic criteria (CASPAR) for psoriatic arthritis. The severity of psoriatic arthritis was assessed using 28-joint Disease Activity Score with CRP. The assessment of skin lesions was performed by Psoriasis Area and Severity Index (PASI) and, additionally, the Body Surface Area (BSA) was calculated. Blood samples were taken to measure the serum concentration of YKL-40, as well as C-reactive protein, erythrocyte sedimentation rate, white blood cell count and neutrophil count.

RESULTS

YKL-40 serum levels were significantly higher in patients with psoriatic arthritis, compared to the control group. Moreover, a significant positive correlation between the activity of psoriatic arthritis measured by DAS 28 and serum level of YKL-40 was found. There was a positive correlation between serum YKL-40 and BSA, as well as a distinct trend towards significance between YKL-40 and PASI score.

CONCLUSIONS

YKL-40 can be a useful biomarker for both diagnosing and monitoring joint involvement in psoriatic patients.

Increased interleukin (IL)-17 serum levels in patients with hidradenitis suppurativa: Implications for treatment with anti-IL-17 agents

BACKGROUND

Biologics seem to offer a promising nonsurgical approach in hidradenitis suppurativa (HS), especially in disease with highly pronounced inflammation. Recent studies revealed increased expression of a broad range of cytokines in lesional HS skin, including interleukin (IL)-17.

OBJECTIVE

This study was undertaken to determine IL-17 serum levels in this group of patients.

METHODS

Our study was conducted on a group of 86 patients between 16 and 72 years of age with HS. A total of 86 matched healthy volunteers constituted the control group. Enzyme-linked immunosorbent assay kits were used to quantify IL-17 serum concentration.

RESULTS

The mean IL-17 serum level of patients with HS was 3.68 ± 2.08 pg/mL, which was significantly elevated (P < .0001) compared with that found in healthy volunteers (2.5 ± 1.11 pg/mL). Moreover, there was a tendency toward higher serum concentrations of IL-17 in patients with more advanced disease (P = .005). Disease duration; patient sex, age, and body mass index; and smoking habits were not determining factors for IL-17 serum concentration.

LIMITATIONS

Hospital-based study population was a limitation, as was a lack of posttreatment assessment.

CONCLUSION

In light of our findings and literature on increased expression of IL-17 in HS lesions, evaluating the clinical effectiveness of using anti-IL-17 agents in the treatment of patients with HS is justified.