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Test Code MONOF Monocyte Repartition by CD14/CD16, Blood


Ordering Guidance


If cytogenetic tests are also desired an additional specimen should be submitted. It is important that the specimen be obtained, processed, and transported according to instructions for the other required test.



Shipping Instructions


Specimens must be refrigerated and received within 3 days of collection.



Specimen Required


Container/Tube:

Preferred: Yellow top (ACD solution A or B)

Acceptable: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.


Useful For

Aiding in the diagnosis and monitoring of chronic myelomonocytic leukemia

Method Name

Immunophenotyping

Reporting Name

Monocyte Repartition by CD14/CD16,B

Specimen Type

Whole blood

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated 72 hours

Reject Due To

Gross hemolysis Reject

Clinical Information

Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) overlap syndrome characterized by peripheral blood monocytosis (absolute monocyte count ≥1.0 x 10(9)/L, ≥10% of the total white blood cell count) persisting for 3 months or greater. It could be very challenging to distinguish CMML from a reactive monocytosis or from a MPN (such as primary myelofibrosis or polycythemia vera) with monocytosis. Monocytes can be classified into 3 subsets: classical MO1 (CD14+/CD16-), intermediate MO2 (CD14+/CD16+), and non-classical MO3 (CD14-/CD16+) monocytes, with MO1 constituting the major monocyte population (85%) in healthy individuals. Recent reports using multiparametric flow cytometry have demonstrated a characteristic increase in classical monocytes (≥94%) in CMML patients, thus distinguishing them from other causes of reactive and clonal monocytosis with greater than 90% sensitivity and specificity.(1) This panel is designed to analyze the repartition of monocytes in these patients and to give a semiquantitative value for the MO1 compartment. This value will aid in the differential diagnosis and monitoring of CMML.

Reference Values

% Monocytes of WBC: 1.0-6.6%

MO1 (classical monocytes): <94.0%

Interpretation

An interpretive report describing the classical monocytes (MO1) fraction as either increased or normal will be provided. See Cautions.

Cautions

Typically, an expanded classical monocytes (MO1) fraction has been seen in patients with chronic myelomonocytic leukemia (CMML).(1,2,3) However, it is not diagnostic of CMML. It can be seen in patients with other myeloid neoplasms (eg, myelodysplastic syndrome, myeloproliferative neoplasm, myelodysplastic/myeloproliferative neoplasm, not otherwise specified) or in reactive conditions. A normal MO1 fraction does not rule out a diagnosis of CMML because it may be seen in CMML patients with autoimmune or inflammatory states or post-therapy.

 

Correlation of these flow cytometry results with bone marrow aspirate and biopsy findings, clinical history, and other laboratory features is required for a definitive diagnosis.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88184-Flow cytometry; first cell surface, cytoplasmic or nuclear marker

88185 x 7-Flow cytometry; additional cell surface, cytoplasmic or nuclear marker (each)

88187-Flow Cytometry Interpretation, 2 to 8 markers

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MONOF Monocyte Repartition by CD14/CD16,B 101146-9

 

Result ID Test Result Name Result LOINC Value
610019 % Monocytes of WBC 101147-7
610020 MO1 (Classical Monocytes) 101148-5
610023 Final Diagnosis In Process

Day(s) Performed

Monday through Saturday

Report Available

1 to 4 days