Backround and purpose: A low Prognostic Nutritional Index (PNI) value, which reflects immune nutrition and inflammation around the tumor, is associated with an unfavorable prognosis, and it was aimed to reveal its prognostic value in metastatic colorectal cancer (CRC). Methods: In our retrospective cross-sectional study, patients with a diagnosis of metastatic colorectal disease without active infection, between January 2010 and December 2016 were included. The PNI values at the time of diagnosis were calculated according to the formula (10 × serum albumin (g/dL)) + (0.005 × total lymphocyte value). Results: The mean PNI value of 253 patients included in the study was 46.6. While 53.75% (n = 136) of the patients had a PNI value of 46.6 and above, 46.25% (n = 117) had a PNI value below 46.6. The overall survival (OS) of the group with a PNI of 46.6 and above was statistically significantly longer (53.06 months vs 38.80 months, p = 0.039). The PFS duration of the group with PNI below 46.6 was 25.66 months, while the PFS duration of the group with PNI above 46.6 was not reached (p = 0.265). Conclusion: PNI is a simple and inexpensive index that evaluates the immunonutritional status, and it is a prognostic marker that can be easily used in patients with metastatic colorectal cancer as in other cancer types.

Neurotrophins such as nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) are crucial for neuronal maintenance and immune regulation. However, their dynamics during coronavirus disease 2019 (COVID-19) remain unclear. In this prospective study, 30 hospitalized patients with PCR-confirmed COVID-19 were evaluated longitudinally. Serum NGF, GDNF, and conventional inflammatory markers (CRP, ESR, fibrinogen, ferritin, D-dimer, LDH, hematological counts) were measured on Day 1, Day 4, and at discharge. A control group of 37 healthy individuals was included for cross-sectional comparison. Both NGF and GDNF levels were significantly lower in COVID-19 patients at admission compared with healthy individuals. NGF showed a modest early decline from Day 1 to Day 4, followed by partial recovery at discharge, whereas GDNF remained stable throughout hospitalization. Inflammatory markers demonstrated expected clinical trajectories: CRP, ESR, LDH, and fibrinogen decreased during recovery, while WBC, neutrophils, and platelets increased. Ferritin and D-dimer showed no meaningful temporal changes. NGF appears to reflect acute neuroimmune activation in COVID-19 and may serve as a dynamic biomarker of early inflammatory resolution. Conversely, GDNF remained persistently suppressed, suggesting a distinct role in chronic neuroimmune regulation. These findings highlight NGF and GDNF as potential targets for monitoring and modulating neuroimmune responses in COVID-19 and other inflammation-driven conditions.