This issue of the ICCS e-Newsletter focuses on flow cytometric testing of specimens from pediatric patients.  In addition to the familiar challenge of maximizing the information obtained from small, difficult to obtain specimens, the pediatric setting often leads to consideration of a different set of disease entities.  This issue addresses two groups of disease that have a higher incidence during childhood: lymphoblastic leukemia and primary immunodeficiency disorders. 

While phenotypic characterization of lymphoblastic leukemia at diagnosis is usually relatively straightforward, detection of minimal residual disease (MRD) following therapy can be difficult.  However, the prognostic value of detecting MRD in pediatric lymphoblastic leukemia is well documented and this, coupled with a desire to intensify therapy where necessary to eradicate disease and reduce therapy where feasible to avoid related complications, has led to increasing demands for MRD testing.  Those of you offering, or considering introducing, flow cytometric testing for minimal residual lymphoblastic leukemia will find the article by Mikhail Roshal useful.

Does your flow cytometry laboratory perform CD4 enumeration for patients infected with HIV?  If so, does it still use a threshold of 200 cells/mm3 for posting interpretive comments and flags?  Although CD4 testing of pediatric and adult specimens is often identical, it is important to be aware of changes in the World Health Organization (WHO) recommendations for starting anti-retroviral therapy (ART).  In 2010 the WHO recommended initiating ART in all HIV-infected infants diagnosed in the first year of life, irrespective of the CD4 count, all HIV infected children between 2 and 5 years of age with a CD4 absolute count ≤750 cells/mm3, and all children more than 5 years of age with a CD4 count of ≤350 cells/mm3 (as in adults).  Visit the WHO website for more information.

Flow cytometric testing also has an important role to play in the primary immunodeficiency disorders (PID).  I had the opportunity to learn more about PID testing by interviewing the directors of four laboratories with recognized expertise in this area.  It was fascinating to hear about the specialized testing required to diagnose some of the rare PID, and reassuring that there are experts to contact when the need arises.  However, it’s important to be aware that some screening tests for PID are relatively straightforward and could be offered by most clinical flow cytometry laboratories, as outlined in e-Newsletter articles on chronic granulomatous disease by Marc Golightly and autoimmune lymphoproliferative disorder by Michele Paessler.

Does your laboratory have anything to share on this, or other flow topics?  Send me an e-mail newsletter@cytometry.org

 



Fiona Craig (Editor)
University of Pittsburgh School of Medicine,
Pittsburgh, PA, USA.