Exploratory Study on Infection and Immunosenescence Based on an Elderly Clinical Cohort

This prospective observational cohort study aims to investigate the relationship between immunosenescence and infectious diseases in older adults. Individuals aged 60 years and older, including elderly patients with infections and healthy controls, will be enrolled and followed longitudinally.

Clinical information, laboratory test results, and health assessment data will be collected. Biological specimens, including peripheral blood, urine, stool, sputum, and nasopharyngeal swabs, will be obtained during enrollment and follow-up. Participants will undergo regular assessments of health status, infection events, and aging-related clinical characteristics.

The study will evaluate age-related changes in immune function, immune cell composition, immune receptor repertoires, epigenetic characteristics, metabolic profiles, and respiratory and gut microbiota. By integrating clinical and multi-omics data, the study aims to identify biomarkers associated with immunosenescence, susceptibility to infection, disease severity, and clinical outcomes in older adults.

The results are expected to improve understanding of the mechanisms linking aging, immune dysfunction, and infectious diseases, and to support the development of predictive models and preventive strategies for infection management and healthy aging in elderly populations.

Study Overview

• Status: Recruiting
• Conditions: Immunosenescence

• Study Type: Observational
• Enrollment (Estimated): 484

Contacts and Locations

• Study Contact: Name: Jingwen Ai, MD; Phone Number: 86+13764990804; Email: jingwenai1990@126.com

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200040
      • Recruiting
      • Huashan Hospital
      • Contact: Jingwen Ai, MD; Phone Number: 86+13764990804; Email: jingwenai1990@126.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Adults aged 60 years and older

Description

Inclusion Criteria for the Healthy Control Group

1. No clinical symptoms suggestive of infection, including fever, cough, dyspnea, fatigue, or myalgia.
2. No abnormal physical signs, including lymphadenopathy, hepatomegaly, splenomegaly, or skin rash.
3. Normal laboratory test results, including complete blood count (CBC), C-reactive protein (CRP), and liver and renal function tests.
4. Healthy adults without underlying chronic diseases, no history of infectious diseases within the previous 6 months, and generally normal cognitive function.
5. Male or female.
6. Able to understand the study procedures and voluntarily provide written informed consent.

Inclusion Criteria for the Infection Group 1.Age: 60 years or older; no gender restrictions. 2. Clinically diagnosed with an infectious disease by the treating physician. 3. The participant provides informed consent and signs the relevant documents.

-------------- Exclusion Criteria for the Healthy Control Group

1. Refusal to participate in the study;
2. Any other condition that, in the opinion of the investigator, makes the participant unsuitable for enrollment.

Exclusion Criteria for the Infection Group

1. Final primary diagnosis is a non-infectious disease (e.g., connective tissue disease, tumor, or other conditions).
2. Positive culture results are determined by the clinician to be due to colonization or contamination rather than infection.
3. Refusal to participate in the study.
4. Patients in critical or severe conditions who are unable to cooperate with sample collection.
5. Other conditions deemed unsuitable for inclusion as determined by the researchers.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Infected Older Adults; Elderly participants aged 60 years or older who meet the study criteria for infectious diseases at enrollment or during the study follow-up period.
Healthy Older Controls; Adults aged 60 years or older who are living independently or receiving routine health examinations and have no evidence of active infection at enrollment or during the study follow-up period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of peripheral immune cell subset	Proportion of peripheral blood immune cell subsets in the infection group versus the healthy control group.	Baseline to 5 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
DNA methylation level	Chromatin accessibility of peripheral blood mononuclear cells.	Baseline to 5 years
Metabolite abundance (metabolomic profiling)	Abundance of metabolites in plasma and urine.	Baseline to 5 years
Respiratory and gut microbiota diversity measured by microbiome sequencing	Diversity of respiratory tract and gut microbiota, measured by microbiome sequencing and reported as the Shannon diversity index.	Baseline to 5 years

Collaborators and Investigators

• Sponsor: Huashan Hospital

Study record dates

Study Major Dates

• Study Start (Actual): November 29, 2024
• Primary Completion (Estimated): December 30, 2028
• Study Completion (Estimated): October 30, 2029

Study Registration Dates

• First Submitted: February 4, 2025
• First Submitted That Met QC Criteria: June 26, 2026
• First Posted (Actual): June 29, 2026

Study Record Updates

• Last Update Posted (Actual): June 29, 2026
• Last Update Submitted That Met QC Criteria: June 26, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: KY2024-1177

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No