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| Dr. William Matzner, Simi Valley, CA |
Excerpt of Article on A Comparison of Flow Cytometry and Microcytotoxicity
for the Evaluation of Alloimmune Therapy in Patients With Recurrent Spontaneous
Abortions, Co-Authored by Dr. William Matzner
This is an excerpt of an article originally published in American journal of Reproductive Immunology. The full article is available here.
INTRODUCTION
The fetus
is an allograft to which the mother must remain immunologically tolerant in
order for the fetus to survive. Much interest has been focused on the
immunology of recurrent spontaneous abortion (RSA). Up to 50% of RSA may be
mediated by the immune system via inadequate maternal anti-paternal antibodies
(which protect the fetus from the mother's immune system) or the presence of
autoantibodies-e.g., antiphospholipid and antinuclear. These are the basis for
immunotherapy with paternal leukocyte immunization (PLI), which has a reported
success rate of 70% to 89% when performed and monitored properly.
There
is confusion regarding the choice of laboratory test that should be performed
to determine levels of maternal anti-paternal leukocyte antibodies (MAPLA). The
methodology employed may have a large impact upon the selection criteria and
adequacy of response to treatment. It is likely that the variations in methods
used to determine MAPLA has accounted for the differences in success rate in
various studies. The most popular methodologies employed include: 1)
microcytotoxicity (MCX), 2) mixed lymphocyte culture (MLC), and 3) cell flow
cytometry crossmatch (FCXM). Each measures slightly different responses-e.g.,
MCX measures only antibodies that fix complement, whereas FCXM measures both
complement and non-complement fixing antibodies. FCXM has been shown to
correlate well with the more difficult MLC assay although the former proves the
more sensitive study. Several studies have used either FCXM or MCX to measure
MAPLA. This work compares the MCX
assay with FCXM.
Patient
Population
The
study group consisted of ten women who had a history of three or more
spontaneous abortions (SABs). All ten had very low levels (<10%) of MAPLA as
measured by FCXM, and all were negative for antibodies as measured by MCX.
Following PLI all subjects demonstrated elevated levels (>50%)
of MAPLA by FCXM.
RESULTS
Prior
to therapy, all 10 patients tested negative for MAPLA as measured both by MCX
and by FCXM. Following PLI all subjects demonstrated elevated levels (>50%)
of MAPLA by FCXM. The 10 subjects became pregnant within 2 months of a positive
MAPLA level, as measured by FCXM. At 12 weeks gestation, sera were
simultaneously measured for MAPLA by MCX and FCXM. While all ten patients had
very high levels of MAPLA to paternal B cells and paternal T cells by FCXM
during pregnancy, only five of ten had antibodies to HLA Class I and two of ten
had antibodies to HLA Class II paternal antigens by MCX. There was a large
variance in the variety of antibodies to paternal HLA, as some women had
antibodies to only two of the father's HLA,
whereas other women had antibodies to as many as seven.
CONCLUSIONS
At
first glance, there is a large discrepancy between the results of MAPLA as
measured by MCX versus FCXM.
These
results, however, are not surprising in an immunologic sense. Other workers
have shown that the majority of antibodies found in the placenta are of the
asymmetric, non-complement fixing variety. In a model similar to paternal
leukocyte immunization, MacLeod et al. reported the appearance of non-cytotoxic
antibodies in transfused patients that reacted with the Fc receptors of B
lymphocytes.
Based
on this preliminary study, the MCX assay is neither sensitive or reliable
enough to determine the need and/or to monitor the effectiveness of PLI. Flow
cytometry should be the modality of choice when determining the need for
alloimmunotherapy and to monitor the effectiveness of treatment.
About William L.
Matzner, M.D., PhD, FACP
Dr.
William Matzner works in the area of healthcare economics consulting at
Healthcare Analytics, LLC, in California. He graduated Phi Beta Kappa from
Stanford University. He received his M.D. with Honors from Baylor College of
Medicine. In 1988, he was the Solomon Scholar for Resident Research at Cedar
Sinai Medical Center. Dr. Matzner subsequently was awarded a PhD in Neuro
Economics from Claremont Graduate University. He is board certified in Internal
Medicine and Palliative Medicine. He has researched and published extensively
on the issue of reproduction and immunology in medical literature. He has been
in private practice since 1989, specializing in Reproductive Immunology and
Internal medicine.
William Matzner, MD (Simi Valley, California), has been practicing medicine since 1989, Internal Medicine and Reproductive Immunology. M.D. with Honors from Baylor College of Medicine.
