Ksymena Leśniak

Dr. Ksymena Leśniak


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2021 in International Journal of Nephrology and Renovascular Disease
Verified
Journal Article
Open access
KLKsymena Leśniak
Ksymena Leśniak
Aleksandra RymarzAleksandra Rymarz
Aleksandra Rymarz
ALArkadiusz Lubas
Arkadiusz Lubas
Stanisław NiemczykStanisław Niemczyk
Stanisław Niemczyk
The management of nonviral cryoglobulinemic vasculitis (CV) has not been established yet. Randomized control trials are challenging to perform because of the rarity of the disease. The most promising biological therapy is rituximab (RTX), an anti-CD 20 monoclonal antibody. The aim of the study was to assess rituximab treatment’s safety and effectiveness in patients with severe noninfectious cryoglobulinemic vasculitis. We retrospectively reviewed 8 courses of RTX treatment in three patients with severe noninfectious CV. In 2 patients, the indication for the start of RTX therapy was the relapse of the disease despite the maintenance treatment, for the third patient, it was the first-line therapy. Clinical, renal, and immunologic efficacy was observed in all evaluable RTX courses. We found a significant decrease of cryoglobulins in the 3-rd month from RTX treatment. However, 5 clinical relapses occurred and two patients experienced severe adverse events (SAEs) after RTX therapy. Patients with SAEs were relatively older and had a longer duration of disease. Lower levels of hemoglobin, C3 component of complement and eGFR as well as higher rheumatoid factor (RF) concentration were observed before RTX treatments complicated with SAEs. Data from our observation show the efficacy of rituximab in the refractory, nonviral cryoglobulinemic vasculitis with a severe course of the disease. However, the therapy is associated with the risk of SAEs, especially in elderly patients with kidney failure and significant immunologic alterations.

24 October 2022 in Nutrients
Verified
Journal Article
Open access
PDF file
KLKsymena Leśniak
Ksymena Leśniak
Aleksandra RymarzAleksandra Rymarz
Aleksandra Rymarz
MSMaria Sobol
Maria Sobol
JDJolanta Dymus
Jolanta Dymus
AWAgnieszka Woźniak-Kosek
Agnieszka Woźniak-Kosek
Stanisław NiemczykStanisław Niemczyk
Stanisław Niemczyk
Background: Chronic kidney disease (CKD) is associated with an accelerated risk of cardiovascular mortality. Hormonal and metabolic disorders in CKD may constitute novel risk factors. Our objective was to characterize and evaluate prognostic implications of circulating sex steroids and selected nutritional parameters in patients at different stages of CKD. Methods: Studied groups were composed of 78 men: 31 on hemodialysis (HD), 17 on peritoneal dialysis (PD), 30 with CKD stage G3-G4. Total testosterone (TT), dehydroepiandrosterone sulphate (DHEA-S), androstenedione, luteinizing hormone (LH), prolactin (PRL), and biochemical parameters were measured; Free testosterone (FT) was calculated. Results: The lowest TT and FT were observed in HD, the highest- in CKD (p = 0.006 for TT, p = 0.005 for FT). TT positively correlated with total cholesterol in HD (p = 0.012), FT negatively correlated with BMI in CKD (p = 0.023). During the 12 months, 9 patients died (5 in the HD, 4 in the PD group). The deceased group had significantly lower concentrations of albumin (p = 0.006) and prealbumin (p = 0.001), and a significantly higher concentration of androstenedione (p = 0.019) than the surviving group. In the group of men on dialysis, a serum TT concentration <2.55 ng/mL (Q1-first quartile) was associated with a 3.7-fold higher risk of death, although statistical significance was not achieved (p = 0.198). After analysis of the ROC curves, the FT level was the best prognostic marker in HD (AUC = 0.788; 95% CI: 0.581–0.996; p = 0.006) Conclusions: Total and free testosterone levels were lower in the HD group than in the CKD group. The nutritional status undoubtedly affects the survival of dialysis patients but also the concentrations of testosterone significantly contributes to further worsening the prognosis.

22 September 2023 in Polish Archives of Internal Medicine
Verified
Journal Article
Closed access
KLKsymena Leśniak
Ksymena Leśniak
HBHanna Behrendt
Hanna Behrendt
ABAnna Bieda
Anna Bieda
SNStanisław Niemczyk
Stanisław Niemczyk
DOI: 10.20452/pamw.16571, Published online: September 22, 2023, Authors: Ksymena Leśniak, Hanna Behrendt, Anna Bieda, Stanisław Niemczyk

23 January 2023 in Nutrients
Verified
Journal Article
Open access
PDF file
KLKsymena Leśniak
Ksymena Leśniak
Aleksandra RymarzAleksandra Rymarz
Aleksandra Rymarz
MSMaria Sobol
Maria Sobol
Stanisław NiemczykStanisław Niemczyk
Stanisław Niemczyk
Background: Some endocrine disorders, previously considered benign, may be related to a poorer prognosis for patients with renal failure. Both low serum free triiodothyronine (fT3) and low total testosterone (TT) concentrations have been considered as predictors of death in dialysis patients, but the results of studies are inconsistent. In our study, we evaluated the relationships of the serum thyroid hormone levels and the total testosterone levels with survival in male dialysis patients. Methods: Forty-eight male dialysis patients, 31 on hemodialysis (HD) and 17 on peritoneal dialysis (PD), aged 61.4 ± 10.0, 59.2 ± 12.2 years, respectively, were included in the study. Serum thyroid hormones and total testosterone were measured. Results: During the 12-month follow-up, nine all-cause deaths were recorded. The concentrations of fT3 were significantly lower in those who died than in the survivors (p = 0.001). We did not observe any statistically considerable differences between the group of men who died and the rest of the participants in terms of the total serum testosterone concentration (p = 0.350). Total testosterone positively correlated with fT3 (r = 0.463, p = 0.009) in the HD group. Conclusions: In the group of male dialysis patients, the serum concentration of fT3 had a better prognostic value in terms of survival than the total testosterone. A linear relationship between the fT3 levels and testosterone levels in men undergoing hemodialysis may confirm the hypothesis that some of the hormonal changes observed in chronic kidney disease (CKD) may have a common cause.

19 April 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
KLKsymena Leśniak
Ksymena Leśniak
ALArkadiusz Lubas
Arkadiusz Lubas
Stanisław NiemczykStanisław Niemczyk
Stanisław Niemczyk
Background: Hypogonadism frequently occurs among men with chronic kidney disease (CKD) and is a highly unfavorable prognostic factor. Therefore, a simple and common screening for testosterone deficiency may be important. The measurement of testosterone in saliva appears to be an attractive alternative to serum testosterone. This study aimed to assess the usefulness of determining free testosterone concentration in saliva to detect testosterone deficiency in men with advanced CKD, including those on dialysis. Methods: A total of 77 adult, male patients (aged 41–89 years old)—30 with CKD stage G3-G4, 30 on hemodialysis (HD), and 17 on peritoneal dialysis (PD)—were evaluated. The concentration of free testosterone was determined in saliva (SalFT), while the concentration of total testosterone (TT) was determined in blood serum. Serum-free testosterone levels were calculated (cFT). Results: SalFT did not differ from cFT in the CKD (p = 0.547) and PD groups (p = 0.409). In the HD group, SalFT was higher than cFT (p = 0.009). SalFT was positively correlated with cFT (r = 0.435 in the CKD and r = 0.479 in the HD) and TT (r = 0.451 in CKD), but only in the group of patients with SalFT levels below 140 pg/mL and 120 pg/mL, respectively. A cut-off value of SalFT ≤ 60.6 pg/mL showed 73.9% sensitivity and 77.8% specificity for testosterone deficiency recognition. Conclusions: Our study supports the value of SalFT measurement as a non-invasive approach in the diagnosis of testosterone deficiency in men with advanced CKD, as well as patients on hemodialysis.

25 August 2024 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
ALArkadiusz Lubas
Arkadiusz Lubas
AZArkadiusz Zegadło
Arkadiusz Zegadło
EFEmilia Frankowska
Emilia Frankowska
EJEwelina Jędrych
Ewelina Jędrych
TLTymoteusz Lubas
Tymoteusz Lubas
Stanisław NiemczykStanisław Niemczyk
Stanisław Niemczyk
Background: A renal artery lumen reduction of ≥60% indicates hemodynamically significant stenosis and is one of the main criteria for invasive revascularization. We hypothesize that direct parameters describing renal artery stenosis (RAS) could better correlate with renal blood flow and improve the criterion for revascularization. This study aimed to investigate RAS parameters independently associated with renal blood flow estimated in contrast-enhanced multidetector computed tomography (CE-MDCT). Methods: Ultrasound Doppler dynamic renal cortical perfusion (dRCP), CE-MDCT with cortical blood flow (CBF), and RAS assessment in the form of cross-sectional area reduction (CSAR), maximal diameter reduction (MaxDR), mean diameter (MeD), and minimal diameter (MinD) were investigated. Results: CBF correlated with CSAR (r = −0.422, p = 0.003), MeD (r = 0.344, p = 0.005) and MinD (r = 0.348, p= 0.005), whereas RCP correlated only with MeD (r = 0.357, p = 0.005) and MinD (r = 0.427, p< 0.001). In multivariable regression, only MeD was independently associated with CBF (R2 = 0.179; p < 0.001), and MeD < 3.5 mm substantially indicated CBF < 175 mL/100 g/min in ROC analysis. Conclusions: The directly measured mean diameter of RAS is independently associated with renal cortex blood flow and is probably a more appropriate parameter for the invasive RAS treatment criterion.