What are the LOINC codes for Absolute Neutrophils, Absolute Lymphocytes, and Absolute Monocytes?

LOINC Codes for Absolute Neutrophils, Absolute Lymphocytes, and Absolute Monocytes

The LOINC codes for Absolute Neutrophils is 751-8, for Absolute Lymphocytes is 731-0, and for Absolute Monocytes is 742-7.

Background on LOINC Codes

LOINC (Logical Observation Identifier Names and Codes) provides a universal standard for identifying laboratory observations in electronic health records and messages 1. These standardized codes are essential for proper integration of laboratory results into clinical and research repositories, ensuring that results are filed correctly across different healthcare systems.

Specific LOINC Codes for Absolute Cell Counts

Absolute Neutrophil Count

• LOINC Code: 751-8
• Description: Neutrophils/volume in Blood
• Units: cells/μL
• Normal range: 1500-7800 cells/μL

Absolute Lymphocyte Count

• LOINC Code: 731-0
• Description: Lymphocytes/volume in Blood
• Units: cells/μL
• Normal range: 850-3900 cells/μL

Absolute Monocyte Count

• LOINC Code: 742-7
• Description: Monocytes/volume in Blood
• Units: cells/μL
• Normal range: 200-950 cells/μL

Clinical Importance of These Parameters

These absolute cell counts are critical laboratory parameters that provide important clinical information:

• Absolute Neutrophil Count (ANC):

  • Serves as a prognostic factor in various conditions
  • High counts may indicate bacterial infection or inflammation
  • Low counts (neutropenia) increase risk of infection

• Absolute Lymphocyte Count (ALC):

  • Important for monitoring immune status
  • Severe lymphopenia (ALC < 500 cells/μL) is associated with worse outcomes in pneumonia and other conditions 2
  • Critical parameter in HIV monitoring

• Absolute Monocyte Count (AMC):

  • Associated with overall survival in certain lymphomas 3
  • Elevated counts may indicate chronic inflammation or certain malignancies

Reporting Guidelines

According to CDC guidelines for laboratory reporting:

1. Report all data with proper CD designation when applicable 4
2. Report both percentages and absolute counts when available 4
3. Include reference ranges appropriate for the patient population (adult vs. pediatric) 4
4. Calculate absolute values by multiplying the cell percentage by the absolute number of leukocytes from the CBC differential 4

Common Pitfalls to Avoid

• Missing LOINC codes: Failure to include proper LOINC codes in laboratory messages can lead to integration errors and misclassification of results
• Incorrect calculation: Ensure absolute counts are properly calculated from percentages when needed
• Misinterpretation: Remember that absolute counts provide more reliable clinical information than percentages alone, especially when total WBC counts are abnormal
• Inconsistent units: Always report in cells/μL (or cells/mm³, which is equivalent) to maintain consistency

Using the correct LOINC codes ensures standardized reporting and proper integration of these important laboratory parameters across healthcare systems.