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Time Sensitive
Ordering Recommendation

Assess B cell subsets of immunodeficiencies. Support the diagnosis of common variable immune deficiency (CVID) and assist in predicting the clinical phenotype. Assess B cell reconstitution after bone marrow or hematopoietic stem cell transplantation. Not recommended for rituximab monitoring; refer to B-cell CD20 Expression (0092099).

Mnemonic
B SUBSETS
Methodology

Flow Cytometry

Performed

Sun-Sat

Reported

1-3 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (K2EDTA) or Pink (K2EDTA).

Specimen Preparation

Transport 4 mL whole blood. (Min: 2 mL) Specimens must be analyzed within 48 hours of collection.

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Clotted or hemolyzed specimens.

Remarks
Stability

Ambient: Unacceptable; Refrigerated: 48 hours; Frozen: Unacceptable

Reference Interval
Test Number
Components
Reference Interval
  CD20+
Age Cells/µL
0-15 years N/A
16 years and older 110-450

  CD20+ %
Age Percent
0-15 years N/A
16 years and older 96.0-100.0

  Activated CD21low CD38-
Age Cells/µL
0-7 days 0-80
8 days-1 month 0-20
2-4 months 0-50
5-8 months 0-50
9-14 months 0-40
15-23 months 10-60
2-4 years 10-60
5-9 years 10-40
10-15 years 10-30
16 years and older 3-26

  Activated CD21low CD38- %
Age Percent
0-7 days 0.5-22.0
8 days-1 month 0.4-2.2
2-4 months 0.5-2.9
5-8 months 0.4-3.3
9-14 months 0.5-4.5
15-23 months 1.0-5.7
2-4 years 1.7-5.4
5-9 years 2.3-10.0
10-15 years 2.7-8.7
16 years and older 1.2-9.0

  Plasmablasts CD38+IgM-
Age Cells/µL
0-7 days 0-10
8 days-1 month 0-30
2-4 months 0-40
5-8 months 0-60
9-14 months 0-30
15-23 months 10-40
2-4 years 10-50
5-9 years 0-30
10-15 years 0-20
16 years and older 1-8

  Plasmablasts CD38+IgM- %
Age Percent
0-7 days 0.2-3.2
8 days-1 month 0.2-2.7
2-4 months 0.4-3.3
5-8 months 0.2-4.0
9-14 months 0.4-5.5
15-23 months 0.5-3.0
2-4 years 0.6-4.0
5-9 years 0.6-5.3
10-15 years 0.6-6.5
16 years and older 0.4-4.1

  CD19+ B cells
Age Cells/µL
0-7 days 200-800
8 days-1 month 700-1800
2-4 months 700-2400
5-8 months 700-2800
9-14 months 400-2900
15-23 months 600-1900
2-4 years 400-1700
5-9 years 300-600
10-15 years 200-600
16 years and older 110-450

  CD19+ B cells %
Age Percent
0-7 days 6.2-25.0
8 days-1 month 10.0-31.0
2-4 months 18.0-38.0
5-8 months 16.0-34.0
9-14 months 14.0-28.0
15-23 months 16.0-34.0
2-4 years 14.0-29.0
5-9 years 10.0-24.0
10-15 years 9.4-23.0
16 years and older 6.4-22.0

  Non switched CD27+IgD+IgM+
Age
Cells/µL
0-7 days 10-40
8 days-1 month 20-50
2-4 months 20-200
5-8 months 30-120
9-14 months 20-140
15-23 months 30-170
2-4 years 20-180
5-9 years 20-100
10-15 years 20-70
16 years and older 5-46

  Non switched CD27+IgD+IgM+ %
Age Percent
0-7 days 2.6-12.0
8 days-1 month 1.7-6.5
2-4 months 2.5-8.7
5-8 months 2.8-7.4
9-14 months 3.0-11.0
15-23 months 4.1-14.0
2-4 years 2.7-20.0
5-9 years 5.2-20.0
10-15 years 4.6-18.0
16 years and older 2.4-15.0

  Class-switched CD27+IgD-IgM-
Age
Cells/µL
0-7 days 10-30
8 days-1 month 10-90
2-4 months 10-170
5-8 months 20-140
9-14 months 10-100
15-23 months 30-180
2-4 years 20-220
5-9 years 40-140
10-15 years 30-110
16 years and older 11-61

  Class-switched CD27+IgD-IgM- %
Age Percent
0-7 days 1.0-7.2
8 days-1 month 1.5-7.1
2-4 months 0.3-9.0
5-8 months 1.6-7.0
9-14 months 1.4-12.0
15-23 months 3.9-14.0
2-4 years 4.7-21.0
5-9 years 11.0-30.0
10-15 years 8.7-26.0
16 years and older 5.1-22.0

  Total Memory CD27+
Age Cells/µL
0-7 days 20-70
8 days-1 month 30-100
2-4 months 40-230
5-8 months 50-270
9-14 months 40-190
15-23 months 50-330
2-4 years 50-390
5-9 years 60-230
10-15 years 50-200
16 years and older 23-110

  Total Memory CD27+ %
Age Percent
0-7 days 3.6-14.0
8 days-1 month 3.1-11.0
2-4 months 3.2-12.0
5-8 months 5.3-12.0
9-14 months 4.1-21.0
15-23 months 9.5-27.0
2-4 years 7.8-37.0
5-9 years 18.6-47.0
10-15 years 13.3-48.0
16 years and older 10.0-33.0

  Transitional CD38+IgM+
Age Cells/µL
0-7 days 0-210
8 days-1 month 50-570
2-4 months 130-940
5-8 months 100-300
9-14 months 20-210
15-23 months 30-200
2-4 years 20-200
5-9 years 10-40
10-15 years 10-60
16 years and older 1-17

  Transitional CD38+IgM+ %
Age Percent
0-7 days 1.2-42.0
8 days-1 month 4.1-44.0
2-4 months 11.0-38.0
5-8 months 7.2-20.0
9-14 months 3.6-13.0
15-23 months 3.3-17.0
2-4 years 3.1-12.0
5-9 years 4.6-8.3
10-15 years 1.4-13.0
16 years and older 0.7-5.9

Interpretive Data

This panel identifies B cell dysregulation.  B cells start development in the bone marrow (stem-cell, pro-B, pre-B), then transition to the spleen and lymph nodes where some mature by acquiring CD27 and switching immunoglobulin class from IgD and IgM to IgG or IgA. Class-switched B cells may further progress to plasmablasts and finally plasma cells.  Different disorders may block different parts of this pathway, disrupting immunoglobulin production. 

This panel can also be used to monitor B cell reconstitution after bone marrow transplantation or targeted B cell depletion therapy.

This panel can assist in the diagnosis and subclassification of Common Variable Immune Deficiency (CVID). CVID is a heterogeneous group of disorders characterized by low antibody production, defective antibody responses, and recurrent infections. Most cases of CVID have a severe reduction in class switched memory B cells (CD27+, IgD-, IgM-) that correlates with granulomatous disease.  Many also have an expanded population of CD21low, CD38low B cells that correlates with splenomegaly. Increased transitional B cells (CD38+, IgM+) in CVID correlates with lymphadenopathy. Most CVID patients have a low percentage of plasmablasts (CD38+, IgM-) that has a correlation with autoimmune cytopenia.

Class switched memory B cells are also low in ALPS, but are typically increased in SLE and infection.

Please note, reference intervals for CD20+ B cells were not established for patients less than 16 years of age. For all other B cell subsets, reference intervals for populations younger than 16 years are adopted from literature. Piatosa B, Wolska-Kusnierz B, Pac M, Siewiera K, Galkowska E, Bernatowska E. B cell subsets in healthy children: Reference values for evaluation of B cell maturation process in peripheral blood. Cytometry Part B 2010; 78B: 372381.

Compliance Category

Analyte Specific Reagent (ASR)

Note
Hotline History
N/A
CPT Codes

86355; 86356 x6

Components
Component Test Code* Component Chart Name LOINC
3002217 CD20+ 9558-8
3002218 CD20+ % 94689-7
3002219 Activated CD21low CD38- 94755-6
3002220 Activated CD21low CD38- % 94754-9
3002225 Plasmablasts CD38+IgM- 89343-8
3002226 Plasmablasts CD38+IgM- % 89344-6
3002227 CD19+ B cells 8116-6
3002228 CD19+ B cells % 8117-4
3002231 Non switched CD27+IgD+IgM+ 89351-1
3002232 Non switched CD27+IgD+IgM+ % 89352-9
3002233 Class-switched CD27+IgD-IgM- 89349-5
3002234 Class-switched CD27+IgD-IgM- % 89350-3
3002235 Total Memory CD27+ 89353-7
3002236 Total Memory CD27+ % 89358-6
3002237 Transitional CD38+IgM+ 89357-8
3002238 Transitional CD38+IgM+ % 89341-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • CVID
  • Memory B-cells
B Cell Subset Analysis