Current Issue

2010, Volume 20, Number 1

Decreasing Health Care Costs by Eliminating the
Over-Utilization of Flow Cytometry

John L. Carey, III, M.D. and David F. Keren M.D.

At a time when health care and its costs are at the forefront of national attention, it is important for laboratorians to scrutinize the testing to ensure that overutilization of laboratory testing is not contributing to unneeded medical expenses.

Recently we conducted a survey of the ordering patterns for flow cytometry and a few ordering patterns were found that do not yield diagnostically useful results.

Flow cytometric evaluation of peripheral blood, bone marrow and lymphoid tissues can be extremely helpful in categorizing many lymphoproliferative conditions.  Unfortunately, perhaps because of the universal acceptance of this premise, some clinicians have been ordering flow cytometry on conditions where this technique does not offer guidance for diagnosis, prognosis or following response to therapy.  The table below provides the most commonly wasteful orders for flow cytometry.

Table. “To Order or Not to Order” Flow Cytometry

Type of Hematolymphoid Neoplasia

Indication for Flow Cytometry

Hodgkin Lymphoma

Never –
Morphology & Immunohistochemistry (IHC) are more sensitive, specific & cost effective.

Plasma Cell Neoplasias

Multiple Myeloma


MGUS

Typically, Never, but…

•  Rarely: Mild Increase in &/or Cytologically Atypical Plasma
   cells + Lack of Clinical / Lab information

•  Uncommon – See Above

Follow up of Diagnosed
Non-Hodgkin’s Lymphoma

Non-Blood Sample:
•  Only when the morphology is  indeterminate on excisional biopsy,
   or Insufficient architecture (Aspirate; Core Biopsy);

Blood:
•  Only if change in neoplastic cell cytology, or
•  Only if cytologically atypical lymphoid cells are newly seen.

Follow up of Diagnosed
Mature Lymphoid Leukemia

Never, unless cytologic transformation

Follow up of Diagnosed
Acute Leukemia

Confirmation of Cytologically Evident Minimal Disease;

Minimal Residual Disease:
•  Never – Adult ALL/AML
•  Never – Pediatric AML
•  Possibly – Pediatric ALL

Myelodysplasia (MDS)

Diagnosis:
•  Never –  on 1st Marrow Evaluation
•  Possibly – on 2nd or more Marrow Exams if 1st Diagnostic Marrow    Workup is Indeterminate


Follow up – Rarely:
•  Clarify Atypical Diagnostically Indeterminate
•  Cytology &/or Confirm Transformation to AML

Chronic Myeloproliferative Neoplasms

Never – Clinical / Morphologic / Genetic Diagnosis

 

Another form of waste we noticed is the order of immune deficiency panels (IDPs) in patients with lymphoproliferative processes. IDPs usually consist of measuring the number of B (CD19+), T (CD3+), Helper T (CD4+3+), Suppressor/cytotoxic T (CD8+3+) and NK (CD16+/56+) cells in a peripheral blood sample. This is redundant and useless information in the primary diagnostic workup of a leukemia/lymphoma. While a CD4/8 ratio may be of use in cases of T cell neoplasia, these markers are included in the T cell panel for leukemia/lymphoma evaluation.  For patients receiving Campath (anti-CD52) Immunotherapy, or certain chemotherapeutic protocols for mature B lymphoid neoplasias, quantification of the total T (CD3+) and CD4+3+ T cells may assist in the timing of initiation and/or cessation of therapy (eg, like HIV patients, if T cell counts fall too low, then the patient is at risk of opportunistic infections).

Some years ago, prior to accurate methods to quantify human immunodeficiency virus (HIV) in peripheral blood, following these parameters were recommended for following patient with HIV infection.  However, the improved molecular techniques available now have decreased the value of this information. IDPs may be a useful screen when dealing with congenital immunodeficiency to quickly detect gross decreases in a major lymphocyte subset.  Although some workers advocate IDP panels for evaluating individuals with fibromyalgia and chronic fatigue syndrome, we do not recommend its use for that unless it is part of a study funded by an independent group and approved by an Institutional Review Board. 

Flow cytometry is just one example of expensive laboratory testing that can be overused.  We hope that this brief note of areas where it is not of clinical use will help to decrease its overutilization.