Plasma Host-Microbe Proteomics to Predict Complications in High-risk Febrile Neutropenia

Official title

A Multicenter Prospective Observational Study on the Plasma Proteomic Profiling of Human and Microbial Proteins for the Early Identification of Biomarker Combinations (Combitypes) Associated With Complications in Oncohematologic Patients With Febrile Neutropenia

Overview

Febrile neutropenia (FN) is a common oncologic emergency in patients with hematologic malignancies, associated with high morbidity and mortality. Early identification of patients at higher risk of complications such as sepsis or septic shock is critical to optimize antimicrobial management. This study aims to characterize the human and microbial plasma proteome using high-resolution mass spectrometry to identify biomarker combinations ("combitypes") capable of predicting complications in oncohematologic patients with FN. A cohort of 350 adult patients with high-risk FN and initially uncomplicated clinical presentation will be enrolled across three tertiary hospitals. Plasma samples will be collected at fever onset (before antibiotic initiation) and after 48 hours. Proteomic data will be integrated with clinical information using multivariate and machine learning models to develop a predictive model for complications.

Detailed description

This multicenter, prospective, observational study will evaluate whether combined proteomic profiles of host and microbial origin can predict complications in patients with hematologic malignancies presenting with high-risk febrile neutropenia (FN).

FN is defined as an oral temperature ≥38.3 °C once or ≥38.0 °C for ≥1 hour in patients with an absolute neutrophil count (ANC) \<500 cells/mm³ or expected to decrease below that threshold within 48 hours. Despite empirical broad-spectrum antibiotics, up to 50% of these patients develop sepsis, and 10% progress to septic shock.

Current biomarkers such as C-reactive protein (CRP) or procalcitonin (PCT) have limited specificity in this immunocompromised population. This study proposes a novel integrative proteomic approach based on mass spectrometry to simultaneously quantify host and microbial proteins in plasma, identifying molecular patterns associated with poor outcomes.

Plasma samples (10 mL, EDTA) will be obtained at two time points: the first febrile episode (prior to antibiotic administration) and 48 hours later. Proteins will be processed using PreOmics® ENRICHplus technology and analyzed via LC-MS/MS on an Evosep One-timsTOF Pro2 platform. Differentially expressed proteins will be identified using a data-independent acquisition (DIA-PASEF) workflow and validated in a subset of 200 patients through targeted mass spectrometry.

Clinical, analytical, and microbiological data will be collected via the REDCap platform. Machine learning models (XGBoost, SHAP interpretability) will be used to generate a predictive risk model for complications, integrating proteomic and clinical data.

This study is expected to establish a new decision-support tool for early identification of high-risk FN patients, facilitating personalized antimicrobial strategies and improved prognosis.

Interventions

• Biological Plasma and DNA sample collection for proteomic and genomic analysis
  Collection of 10 mL of peripheral blood in EDTA tubes at fever onset (before antibiotic initiation) and 48 hours later for proteomic and genomic analysis. Samples are processed to obtain plasma and DNA, which will be used for mass spectrometry-based proteomics and potential metagenomic studies.

Primary outcome measures

• Identification of plasma host-microbial proteomic signatures (combitypes) associated with major complications in febrile neutropenia. [Time frame: Within 7 days from fever onset.]

Secondary outcome measures (5)

• Dynamic changes in plasma proteome over 48 hours [Time frame: 0-48 hours]
• Predictive performance of identified combitypes versus conventional biomarkers (CRP, PCT) [Time frame: Up to 7 days.]
• Correlation between microbial proteomic profiles and microbiologically documented infections [Time frame: During hospitalization (up to 30 days).]
• Development of a predictive model for complications [Time frame: Study duration (36 months).]
• Validation of selected protein biomarkers by targeted mass spectrometry [Time frame: By end of study (month 36).]

Eligibility criteria

Inclusion criteria

• Adults (≥18 years).
• Written informed consent provided by patient or legal representative.
• Diagnosis of hematologic malignancy under induction chemotherapy, post-allogeneic hematopoietic stem cell transplantation, or CAR-T therapy.
• High-risk febrile neutropenia (ANC ≤ 100 cells/mm³, expected duration ≥ 7 days, or significant comorbidities).
• Fever defined as oral temperature ≥38.3 °C once or ≥38.0 °C for ≥1 hour.
• Hospitalized or requiring immediate admission at the time of FN diagnosis.

´- Initial uncomplicated clinical presentation, with no previous infection or colonization by multidrug-resistant bacteria.

• Eligible for initial monotherapy with broad-spectrum empirical antibiotic.
• Availability for serial plasma sampling and clinical follow-up.

Exclusion criteria

• Age <18 years.
• Low-risk FN according to MASCC/CISNE criteria.
• Initial sample collected after antibiotic administration.
• Decline or inability to provide informed consent.
• Any condition preventing safe participation or reliable sample collection.
• Fever induced by noninfectious causes (considered as adjustment factor, not exclusion).

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Spain · 3 centers

• Hospital Universitari Vall d'Hebron — Barcelona
• Complejo Asistencial Universitario de Salamanca — Salamanca
• Hospital Universitario Virgen Macarena — Seville

Identifiers

NCT: NCT07277387 · COMBITYPES-FN

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗