To evaluate the immune status and prognosis of patients with malignant hematological tumors, thereby guiding clinical therapeutic strategies.

Primary Objective:

To evaluate the immune status and prognosis of patients with newly diagnosed or relapsed B-cell lymphoma and multiple myeloma by dynamically monitoring peripheral blood thymus seeding progenitors (TSP), recent thymic emigrants (RTE), T-cell receptor rearrangement excision circles (TREC), naive T-cells, and developmental/functional T-cell subsets before and after treatment, thereby guiding clinical therapeutic strategies.

Secondary Objective:

To monitor remission rates, survival outcomes, and infection rates in patients with hematological malignancies, and to explore their association with dynamic changes in developmental/functional T-cell subsets.

Inclusion Criteria:

1. Age ≥ 18 years; both genders included; expected survival > 3 months;
2. Cohort 1: Patients with newly diagnosed or relapsed B-cell lymphoma confirmed by histopathology, bone marrow pathology, flow cytometry, morphology, and genetic testing; Cohort 2: Patients with newly diagnosed or relapsed multiple myeloma confirmed by the same methods; Cohort 3: Healthy volunteers;
3. Able to understand and voluntarily sign the informed consent form.

Exclusion Criteria:

1. Significant pulmonary disease:

   Chronic obstructive pulmonary disease (COPD) with forced expiratory volume in 1 second (FEV1) <50% of predicted normal value. Note: Suspected COPD cases require FEV1 testing; subjects with FEV1 <50% of predicted must be excluded.

   Moderate/severe persistent asthma within the past 2 years, or currently uncontrolled asthma of any severity. (Note: Controlled intermittent or mild persistent asthma is permitted.)

2. Symptomatic congestive heart failure (NYHA Class II-IV), symptomatic/uncontrolled arrhythmias, congenital long QT syndrome, or corrected QT interval (QTc) >500 ms (Fridericia formula) at screening.

3. History of pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, drug-related pneumonitis, or severely impaired lung function.

4. HIV infection (positive HIV-1/2 antibodies) or known syphilis infection.

5. Unhealed wounds, fractures, gastroduodenal ulcers, persistent fecal occult blood positivity, ulcerative colitis, or other conditions at risk of gastrointestinal bleeding/perforation (as determined by the investigator).

6. Severe neurological/psychiatric disorders, immunodeficiency, hepatitis/cirrhosis, or other conditions deemed unsuitable for study participation by the investigator.

Cohort 1: 25 patients with newly diagnosed or relapsed B-cell lymphoma; Cohort 2: 25 patients with newly diagnosed or relapsed multiple myeloma; Cohort 3: 25 healthy controls.