Abnormal Lymphocyte Subset Percentages in Adult Peripheral Blood
The CD19 (60%) value is abnormal in adult peripheral blood. 1
Normal Reference Ranges for Lymphocyte Subsets
Lymphocyte subset analysis is a critical component of immune system evaluation. According to CDC guidelines, the normal ranges for major lymphocyte subsets in adults are:
- CD3+ (T cells): 56.5-84.7% 1
- CD4+ (T helper cells): 30.3-55.7% 1
- CD8+ (T cytotoxic cells): 13.2-42.9% 1
- CD19+ (B cells): 5.4-19.13% 1, 2
- CD3-/CD56+ (NK cells): 3.7-28.0% 3
Analysis of Each Option
Let's analyze each of the options presented in the question:
CD4 (42%) - This value falls within the normal reference range of 30.3-55.7% for adult peripheral blood. 1
CD19 (60%) - This value is significantly elevated above the normal reference range of 5.4-19.13% for B cells in adult peripheral blood. 1, 2 The CDC guidelines specifically state that the sum of T cells (CD3+), B cells (CD19+), and NK cells should equal 95-105% of lymphocytes, and B cells should typically represent only about 5-19% of total lymphocytes. 1
CD8 (20%) - This value falls within the normal reference range of 13.2-42.9% for adult peripheral blood. 1
CD3 (70%) - This value falls within the normal reference range of 56.5-84.7% for adult peripheral blood. 1
Clinical Significance of Abnormal CD19 Percentage
An elevated CD19+ percentage of 60% is highly abnormal and may indicate:
- B-cell lymphoproliferative disorders, including chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) 1
- Certain autoimmune conditions
- Acute viral infections
According to the NCCN guidelines for CLL/SLL, the diagnosis requires the presence of clonal B lymphocytes with a characteristic immunophenotype (CD5+, CD19+, CD20+ (low), CD23+, sIg low, CD79b low, FMC7–) 1. A markedly elevated CD19 percentage warrants further investigation to rule out these conditions.
Quality Control Considerations
The CDC guidelines for lymphocyte subset analysis specify that:
- The sum of CD3+ (T cells), CD19+ (B cells), and CD3-/CD16+/CD56+ (NK cells) should optimally equal the purity of lymphocytes in the gate ±5%, with a maximum variability of ≤10% 1
- When data are corrected for lymphocyte purity, the sum should equal 95-105% (minimum 90-110%) 1
A CD19 percentage of 60% would likely cause these quality control parameters to be violated, further confirming its abnormality.
Conclusion
Among the options presented, CD19 (60%) is the only abnormal result, as it significantly exceeds the established reference range for B cells in adult peripheral blood. This finding warrants further investigation to determine the underlying cause of B-cell expansion.