This is a single-center, investigator-initiated, prospective observational case-control study. Patients with intracerebral hemorrhage and healthy controls will be enrolled at Xuanwu Hospital, Capital Medical University. Peripheral venous blood samples will be collected for measurement of CIRP, Cathepsin B, and related inflammatory biomarkers. Clinical and imaging data will also be collected in the intracerebral hemorrhage group. The study aims to compare biomarker levels between patients with intracerebral hemorrhage and healthy controls and to explore the potential role of these biomarkers in neuroinflammation after intracerebral hemorrhage. No investigational treatment will be administered.

Intracerebral hemorrhage (ICH) is a severe subtype of stroke with high mortality and disability. In addition to the primary mass effect caused by hematoma, secondary brain injury, especially neuroinflammation, is considered a major contributor to neurological deterioration after ICH. Cold-inducible RNA-binding protein (CIRP) is a stress-related molecule with pro-inflammatory properties, while Cathepsin B is a lysosomal protease involved in inflammasome activation, cellular stress, and tissue injury. Experimental evidence suggests that both CIRP and Cathepsin B may participate in inflammatory amplification after ICH, but their expression patterns and clinical relevance in patients with ICH remain insufficiently characterized.

This study is a single-center, investigator-initiated, prospective observational case-control study conducted at Xuanwu Hospital, Capital Medical University. A total of 60 participants will be enrolled, including 40 patients with intracerebral hemorrhage and 20 healthy controls. The ICH group will consist of adult patients with supratentorial intracerebral hemorrhage confirmed by CT or MRI, admitted within 24 hours after symptom onset, with hematoma volume less than 30 mL and no surgical treatment. Healthy controls will be recruited from the hospital health examination center.

For the ICH group, demographic information, medical history, time from onset to admission, vital signs, laboratory test results, imaging findings, and treatment information will be collected. For the healthy control group, demographic information, medical history, and health examination-related information will be collected. Peripheral venous blood samples (4-5 mL) will be obtained from both groups. In the ICH group, residual blood samples generated during routine clinical care will be used whenever possible; if residual samples are insufficient and study needs require, a small additional blood sample may be collected together with routine blood drawing after informed consent. In the healthy control group, one peripheral venous blood sample will be collected after informed consent. All samples will be processed, aliquoted, and stored at low temperature for subsequent measurement of CIRP, Cathepsin B, and related inflammatory biomarkers.

The primary objective of the study is to compare peripheral blood CIRP levels between the ICH group and the healthy control group. Secondary objectives include comparing peripheral blood Cathepsin B and related inflammatory biomarkers between the two groups, and exploring the potential clinical significance of these biomarkers in neuroinflammation after ICH. No investigational drugs, biologics, or devices will be administered in this study. The results are expected to provide clinical evidence for future mechanistic and translational studies targeting CIRP- and Cathepsin B-related pathways in ICH.

Inclusion Criteria:

Intracerebral hemorrhage group:

Age 18 years or older Diagnosis of intracerebral hemorrhage confirmed by head CT or MRI Supratentorial hemorrhage No surgical treatment Hematoma volume less than 30 mL Admission within 24 hours after symptom onset The participant or the legally authorized representative/next of kin is able to provide written informed consent

Healthy control group:

Age 18 years or older Recruited from the hospital health examination center No history of stroke, intracerebral hemorrhage, cerebral infarction, or other major neurological diseases No severe active infection, severe immune disease, hematologic disease, or end-stage severe heart, liver, or renal failure No acute infection, trauma, or other obvious stress state within the previous 2 weeks Able to provide written informed consent

Exclusion Criteria:

Intracerebral hemorrhage group:

Traumatic intracerebral hemorrhage Secondary intracerebral hemorrhage caused by brain tumor, cerebrovascular malformation, aneurysm, or hemorrhagic transformation of infarction Severe active infection, severe immune disease, or hematologic disease End-stage severe heart, liver, or renal failure Pregnant or lactating women Any other condition judged unsuitable by the investigator

Healthy control group:

History of stroke, intracranial hemorrhage, brain tumor, or other major neurological diseases Severe active infection, severe immune disease, or hematologic disease End-stage severe heart, liver, or renal failure Pregnant or lactating women Any other condition judged unsuitable by the investigator

Adults with intracerebral hemorrhage admitted to Xuanwu Hospital, Capital Medical University, and age-eligible healthy controls recruited from the hospital health examination center. The intracerebral hemorrhage group includes patients with supratentorial, non-surgical intracerebral hemorrhage confirmed by CT or MRI and admitted within 24 hours after symptom onset. The healthy control group includes adults without stroke or other major neurological diseases.

IPD will not be shared due to participant privacy and confidentiality considerations. This is a single-center study involving sensitive clinical and biospecimen-derived data, and no formal external data-sharing plan has been established. Results will be reported in aggregate form only.