Evaluation of serum neopterin levels in severe COVID-19 patients: An observational study.

In patients with coronavirus disease (COVID-19), a massive inflammatory response is a significant cause of morbidity and mortality. Inflammatory markers are prognostic indicators of disease severity and the ultimate clinical outcome. Several studies have demonstrated a correlation between serum levels of neopterin, which can be an immune system marker, disease severity, and poor outcomes in COVID-19 patients. Our study aimed to determine the diagnostic significance of neopterin in conjunction with routinely measured inflammatory markers in patients with severe COVID-19. Serum neopterin, C-reactive protein (CRP), albumin levels, and complete blood count were determined in 39 patients with severe COVID-19 and 30 healthy individuals. Demographic characteristics, serum neopterin levels, and other laboratory data were compared between patients and healthy volunteers and statistically analyzed. High neopterin levels were observed in patients with severe COVID-19 compared to healthy volunteers. Furthermore, albumin levels were decreased, while CRP levels were increased in patients, statistically significantly. Also, positive correlations were shown between serum neopterin levels and serum CRP levels, while negative correlations were shown between serum neopterin levels and serum albumin levels. Systemic inflammation markers, CRP/albumin ratio, neutrophil/lymphocyte ratio, and platelet/lymphocyte ratio were significantly higher, while lymphocyte/monocyte ratio was also significantly lower in patients with severe COVID-19 than in healthy volunteers. However, serum neopterin levels were not linked to the CRP/albumin ratio, the neutrophil/lymphocyte ratio, or the platelet/lymphocyte ratio. On the other hand, they were linked negatively to the lymphocyte/monocyte ratio. Our findings highlight the association between high neopterin levels and patients with severe COVID-19. Neopterin is correlated with traditional inflammatory biomarkers and may indicate general immune and inflammatory activation in patients with severe COVID-19.

Predictors of 3-month mortality with muscle ultrasound and palliative prognostic tools among patients admitted to palliative care units.

BACKGROUND/AIMS: Prognostic factors are an important issue in progressive and life-limiting diseases. This study evaluate 3-month mortality in patients admitted to the palliative care unit (PCU). METHODS: In this study, the patient's demographics, comorbidities, nutritional status, and laboratory values were recorded. The palliative performance scale (PPS), the palliative prognostic index (PPI), and the palliative prognostic (PaP) score were calculated. The rectus femoris (RF) cross-sectional area (CSA), RF muscle thickness, gastrocnemius (GC) medialis muscle thickness, pennation angle and fascicle length of the GC were measured by ultrasound for survival prediction. RESULTS: A total of 88 patients enrolled during the study period, with a mean age of 73.6 ± 13.3 years and a 3-month mortality rate of 59.1%. The findings of a multivariable Cox proportional hazards regression model based on age, gender, C-reactive protein level and Nutrition Risk Screening 2002 scores as covariates revealed the PPI and the PaP score to be significant predictors of 3-month mortality. In addition, in the unadjusted Cox proportional hazard regression analysis, the CSA of the RF muscle was also found to be a significant predictor of 3-month mortality. CONCLUSION: Findings revealed that the combined use of the CSA of the RF, the PPI, and the PaP score are reliable predictors of mortality in patients admitted to the PCU.

Cellular immunity in subacute thyroiditis: a new perspective through neopterin.

Subacute thyroiditis (SAT) is an inflammatory disorder of the thyroid gland. Although its etiology is not fully understood, it is believed to occur shortly after viral infections and is mostly associated with human leukocyte antigen (HLA)-B*35. Cellular immunity is prominent in SAT. Neopterin is produced by activated monocytes/macrophages and is a marker of cellular immunity. Its production is stimulated by interferon gamma (IFN-γ), provided mainly by activated helper T lymphocytes type 1 (Th1) in the adaptive immune system. Therefore, with these cells' activation, an increase in serum neopterin levels is expected. We aimed to evaluate neopterin levels in demonstrating cellular immunity in SAT and compared 15 SAT patients with 16 healthy controls. Since all SAT patients were in the active thyrotoxic phase, we found a significant difference in thyroid functions. Classical inflammatory markers, erythrocyte sedimentation rate, and C-reactive protein were markedly elevated in the patient group. Although we expected to find an increase considering that cellular immunity is at the forefront in the pathogenesis of SAT, we found serum neopterin levels significantly lower in the patient group than in the control group. There is an increase in CD8+ T cells in the thyroid tissue in SAT. The possible relationship with HLA-B*35- major histocompatibility complex class I in SAT, and the antigen presentation to CD8+ T cells may be the reason why we observed low serum neopterin levels in patients due to the cytokine imbalance. Neopterin provides unique and independent data from classical acute phase response indicators.

Neopterin and biopterin levels and tryptophan degradation in patients with diabetes.

This study aimed to evaluate the possible changes of neopterin, biopterin levels and tryptophan degradation in diabetes and to compare the results within diabetes groups and with healthy subjects. Diabetes mellitus patients and healthy controls were recruited the study. Patients were further subgrouped according to their drug therapy. Serum neopterin concentrations were detected by ELISA. Urinary neopterin, biopterin, serum tryptophan (Trp) and kynurenine (Kyn) levels were detected by HPLC. There was no difference between controls and diabetes patients in serum neopterin, urinary neopterin and biopterin levels (p > 0.05, all). Serum Trp and Kyn levels were significantly different in type 1 diabetes (T1DM) patients compared to controls (p < 0.05, both). Serum neopterin levels were significantly higher in type 2 diabetes patients (T2DM) compared to T1DM (p < 0.05). Urinary biopterin levels of T2DM patients using both metformin and vildagliptin were significantly higher than T1DM patients (p < 0.05). The correlations between serum neopterin and urinary neopterin, Kyn and Kyn/Trp were statistically significant in control and patient groups (p < 0.05, all). The study showed that Kyn/Trp was altered in diabetes patients due to immune modulation. On the other hand, although xenobiotic exposure may change pteridine levels, metformin and/or vildagliptin use in T2DM patients did not have any effect on the measured parameters.