RE: Feto-maternal Hemorrhage (FMH)

Alfonso,

Determination of fetal HbF by flow cytometry is by far more superior method than old K-B
test, so no conjunction is needed. First, it is more sensitive and number of false
positive / false negative results goes down. Second, flow test not only distinguishes
fetal red cells from adult red cells, it also allows you to identify a population of
F-cells (adult red cells carrying fetal form of hemoglobin). K-B test will count these
cells as fetal and report positive answer. In reality this result is negative, and
presence of F-cells (which points to sickle cell anemia, MDS and thousand other medical
conditions) is no harm for fetus development.
I spent a lot of useless time, trying to convince my doctors to start this test for our
hospital (the biggest Women's Center in US) and did not achieve much. The reason: doctors
want it to be done on 24 / 7 mode, which can be done in 24 hours functioning hematology
lab, but cannot be done in Flow lab. I know quite a few people in US, who experience the
same trouble. Some labs were able to manage flow-base test on Monday-Friday, 8 to 6, and
K-B out of business hours. I could not get it through. Since I have tried it so hard, I
still have a presentation with numbers and ideas, supporting transition from K-B to flow
cytometry. If interested, get back to me and I will send it to you.

Meanwhile, if you decide to go with a flow test, you can either do one-color flow, using
AB from Caltag (Invitrogen now) and 3-level positive control, called Fetaltrol. They have
distributors in Europe. Or you can find 2-color flow kit from company IQ (Netherlands),
which supposely gives you more clear results on possible F-cells presence. For myself I
like one-color flow just fine (combination of quality and price), but all this is
personal.

Good luck and if you have any additional questions, do not hesitate to contact me.

Irina

Irina Grigorieva, PhD
Director, Flow Cytometry Laboratory,
Northside Hospital, Atlanta, GA
voice (404)-851-6541
fax (404)-845-5353

-----Original Message-----
From: Alfonso Blanco [mailto:alfonso.blanco@ucd.ie] 
Sent: Monday, March 10, 2008 7:03 AM
To: cyto-inbox
Subject: Feto-maternal Hemorrhage (FMH)


Dear Flow-ers,

I've a group that would like to answer the frequently asked questions 
that are asked by clinicians in hospitals:

1. Is there a benefit to performing flow cytometry for Feto-maternal 
Hemorrhage (FMH) estimation ante-natal?
2. If so, what exclusive fetal markers are available for flow to be 
preformed ante-natal following FMH?


Right now in the laboratory they quantify peri-natal samples with 
monoclonal antibody to RhD positive fetal RBCs in Rh negative mothers 
using FCM. Ideally the MoAb would have a specificity to an epitope on 
the fetal cells and absent from the maternal cells, and would be 
targeting a cell surface antigen so it could be run with the RhD MoAb 
used at the moment to quantify Feto-maternal Hemorrhage (FMH) on a 
maternal sample.

I was looking around and looks like it's necessary to work with flow 
cytometry in conjunction with Kleihauer-Betke Test, because you can 
underestimates massive FMH. Nevertheless, it looks like in general 
there is a good correlation between both methods. In terms of MoAb for 
Flow, i.e. Invitrogen has a kit (with three options) for flow. 

Could you help me with this? I would like to know what clinicians and 
flow people are doing for the detection of FMH. 

Thanks in advance for your help.

Regards,

Alfonso


------------------------------
 Dr. Alfonso Blanco Fernández

 Flow Cytometry Core Facilities
 UCD - Conway Institute of Biomolecular & Biomedical Research
 University College Dublin
 Belfield, Dublin 4
 IRELAND

 T: 00353(0)1 716 6836/6947







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