Hodgkin’s lymphoma (HL) is a cancer of the lymphocytes, a type of white blood cell, that typically starts in the lymph nodes of the neck or chest and can spread throughout the body. Blood tests are supporting tools, not definitive for diagnosis; a biopsy is always required to confirm the presence of characteristic Reed-Sternberg cells. However, blood work provides medical professionals with important information about the disease’s effects, its extent, and the patient’s general health status. These assessments influence staging, treatment planning, and monitoring over time.
Screening Tests: Assessing General Health and Anemia
The initial workup for Hodgkin’s lymphoma often includes a Complete Blood Count (CBC), which measures the different types of cells circulating in the blood. This test helps to identify general health issues that may be caused by the underlying cancer or other conditions. In HL, a common finding is anemia, a low red blood cell count, which is often the anemia of chronic disease resulting from systemic inflammation.
The CBC may also show changes in white blood cell populations, such as lymphopenia, which is an abnormally low number of lymphocytes, or leukocytosis, an elevated white blood cell count. Specifically, a high number of neutrophils (neutrophilia) or eosinophils (eosinophilia) can sometimes be observed in HL patients. These findings are non-specific, meaning they can be caused by many issues, including infection or other cancers, and do not confirm an HL diagnosis.
Further general screening involves a blood chemistry study, often referred to as a Basic Metabolic Panel or Liver Function Tests. These tests assess how well organs like the liver and kidneys are functioning, which is important for establishing a baseline before treatment. Abnormal levels of enzymes like alkaline phosphatase can suggest the lymphoma has spread to the liver or bone. While these initial blood screens flag potential problems, the definitive diagnosis relies on examining a tissue sample under a microscope.
Markers of Disease Activity and Systemic Impact
Once an underlying issue is suspected, more specific blood markers are used to gauge the cancer’s systemic impact and help determine prognosis. The Erythrocyte Sedimentation Rate (ESR) is a simple test that measures how quickly red blood cells settle to the bottom of a test tube. A high ESR indicates the presence of widespread inflammation, a common feature of Hodgkin’s lymphoma, particularly when patients experience systemic symptoms like unexplained fever or weight loss.
Another important marker is Lactate Dehydrogenase (LDH), an enzyme found in almost all body cells, which is released into the blood when cells are damaged or dying. Elevated LDH levels often correlate with a higher tumor burden or more aggressive disease activity, as the rapidly dividing cancer cells increase cellular turnover. While not exclusive to HL, a significantly increased LDH level is a factor used in risk stratification for the disease.
The protein Beta-2 Microglobulin (B2M) can be measured in the blood. This protein is shed by both lymphoma cells and normal immune cells, and elevated levels are often seen in advanced-stage disease. High B2M is considered a poor prognostic indicator, linked to decreased overall survival in some patients with HL. The combined assessment of these markers provides a snapshot of the disease’s overall biological effect on the body.
The Use of Blood Tests for Monitoring Treatment
After Hodgkin’s lymphoma is diagnosed and treatment, such as chemotherapy, is initiated, blood tests monitor the patient’s response and manage care. Regularly checking the CBC is paramount for identifying side effects of chemotherapy, particularly myelosuppression (suppression of bone marrow activity). Low counts of white blood cells, especially neutrophils (neutropenia), are a serious side effect that increases the risk of life-threatening infection.
Changes in the levels of disease activity markers like LDH and ESR are closely tracked to assess the effectiveness of the treatment regimen. A successful response is typically indicated by a progressive decrease in previously elevated LDH and ESR values, suggesting that the tumor burden and systemic inflammation are diminishing. Conversely, stable or rising levels may indicate that the cancer is resistant to the current therapy or that the disease is progressing.
These same blood tests are used in long-term surveillance after a patient achieves remission. Although a relapse is most often suspected based on new symptoms or imaging, an unexpected rise in LDH or ESR can be an early biochemical warning sign that the lymphoma may have returned. Continuous monitoring of the complete blood count and metabolic panels also ensures that the patient’s organs are recovering from the treatment and that no late-onset toxicities are developing.