Excerpt of Article on A Comparison of Flow Cytometry and Microcytotoxicity for the Evaluation of Alloimmune Therapy in Patients With Recurrent Spontaneous Abortions


Dr. William Matzner, Simi Valley, California
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. 

News: https://medicogazette.com/dr-william-matzner

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.

Featured Blog Article

QUALITY ADJUSTED LIFE YEARS (QALY)—THE FORGOTTEN DENOMINATOR

Dr. William Matzner, Simi Valley, California Author’s NOTE: The health promotion and wellness industry has often been asked to illustr...