Background/Objectives: In hematological patients receiving treatment for lymphomas, febrile neutropenia (FN) is a serious complication associated with significant morbidity and mortality. This prospective study aimed to evaluate the diagnostic and prognostic value of the novel biomarker presepsin (PSP) in episodes of FN in this specific cohort of patients. Methods: The study enrolled 37 patients with FN and 18 patients with neutropenia without fever as a control group. Patients with FN were divided into two groups: those with confirmed infections and those without them. Various clinical and laboratory parameters were analyzed, including inflammatory and biochemical markers, focusing on implications of PSP. Results: Among patients with FN, 65% had proven infections with significantly higher PSP levels compared to those without infections and control group (p < 0.001). Positive blood cultures were found in 13.5% of all FN episodes. PSP showed greater sensitivity than traditional biomarkers like procalcitonin and C-reactive protein for differentiating septic from non-septic complications. Increased PSP levels at admission suggested a poorer survival prognosis. Each 1 ng/mL increase in PSP correlated with a 5% increase in mortality risk (HR 1.05; p < 0.001), with a one-year mortality rate of 56.7%, underscoring the necessity for better predictive markers. Other markers, including CRP, PCT, IgG, and albumin, were not significantly associated with mortality; however, platelets and qSOFA exhibited borderline significance. Conclusions: PSP is a valuable biomarker for identifying high-risk FN in lymphoma patients and predicting mortality, correlating with infection severity. Larger multi-center studies are needed to validate these findings and optimize PSP’s clinical application to improve outcomes.

Background: Mild asthma is often characterized by normal spirometric values and a negative bronchodilation test (BDT), which makes accurate diagnosis challenging. The aim of our study was to evaluate the diagnostic accuracy of fractional exhaled nitric oxide (FeNO) in mild asthma. Methods: In adults with symptoms suggestive of asthma and normal spirometry values, BDT, FeNO, BPT and skin prick testing were performed. Patients with positive BPT started inhaled corticosteroid (ICS) therapy. Those with positive response to ICS were considered asthmatics. Results: There were 142 asthmatics and 140 non-asthmatics. No significant difference was found in BDT between the groups, p = 0.233. Median FeNO levels were significantly higher in the asthma group (49.5 ppb) than in the non-asthma group (23 ppb), p < 0.001. BPT was positive in 145 (51.42%) and negative in 137 (48.58%) patients. Positive response to ICS treatment was recorded in 142/145 (97.9%) patients. In diagnosing asthma, FeNO ≥ 25 ppb had a sensitivity of 75.4% and specificity of 47.9%. Conclusions: FeNO has insufficient sensitivity and specificity in mild asthma and the application of BPT is often necessary to establish an accurate diagnosis.