Medical Necessity Documentation:
Client Notes:
Patient Preparation:
Specimen Requirements:
4.0 mL Whole Blood in a Lavender Top Tube - EDTA
Collection Instructions:
Draw and send to Parkview Lab Monday thru Thursday Only,
Specimen must be at testing laboratory (ARUP) within 48 hours of collection.
Minimum Volume:
2.0 mL Whole Blood
Transport & Storage: Temperature/Stability:
Unacceptable Ambient
48 hours Refrigerated
Unacceptable Frozen
Rejection Criteria:
Specimens older than 48 hours. Clotted or hemolyzed specimens. Ambient or Frozen Specimens
Reference Range:
Refer to Interpretive Results
Critical Ranges:
Test Comments:
Methodology:
Flow Cytometry
Clinical Significance:
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.
Documentation:
Custom Panel:
No
PRODUCTION SCHEDULE
Turn Around Time:
1 to 3 days
Days Performed:
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday
Sites Performed:
ARUP Lab
PHL Test Code:
MSOT
EPIC Test Code:
MISC
Send Out Test Code:
3002216
Alternate Test Names:
B Subsets; CVID; Memory B Cell ; Memory B-cells
Included Tests:
CPT Coding:
86355; 86356 x6