Tubal abortions but not viable tubal pregnancies are characterized by an increased number of CD8+ T cells.
OBJECTIVE
To examine immune cell phenotypes in viable tubal pregnancies (VTP) and in tubal abortions (TA).


METHODS
Paraffin-embedded specimens of VTP (n=7) and ongoing TA (n=6) were double-stained for cytokeratin for trophoblast as well as for CD45, CD3, CD8, CD68 and CD20 for immune cell phenotypes. In all cases, the amniotic sac was detected by ultrasound. Histological examination showed no evidence of necrosis within the tissues included in this study. Quantification of the subpopulations was performed in each slide by two independent examiners in five areas (0.085 mm2 each) of the invasion zone as marked by cytokeratin-positive stromal extravillous trophoblast (EVT) cells. For statistical analysis, the non-parametric two-tailed t-test was used (p<0.05).


RESULTS
The differences in the number of CD45(+), CD68(+) and CD20(+) cells was significant (p=0.0423, p=0.0469 and p=0.0494, respectively); however, the number of CD3(+), and among those the number of CD8(+) cells, was approximately eight-fold higher in TA than in VTP (p<0.0001 and p=0.0012, respectively).


CONCLUSIONS
The unequal distribution of CD8(+) cells in VTP and TA suggests a significant role of this immune cell phenotype in the further outcome of a tubal pregnancy either to an abortive or a viable, potentially life-threatening, entity.
Kemp
Birgit
B
Department of Obstetrics and Gynecology, Medical School, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany. Electronic address: bkemp@ukaachen.de.
Rimbach
Stefan
S
Department of Obstetrics and Gynecology, Medical School, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany.
Kämmerer
Ulrike
U
Department of Obstetrics and Gynecology, Medical School, University of Würzburg, Josef-Schneider-Str. 4, 97080 Würzburg, Germany.
Rath
Werner
W
Department of Obstetrics and Gynecology, Medical School, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany.
Beier
Henning M
HM
Institute of Anatomy and Reproductive Biology, Medical School, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany.
von Rango
Ulrike
U
Institute of Anatomy and Reproductive Biology, Medical School, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany.
D000022:Abortion, Spontaneous / Q000276:immunology* / Q000473:pathology; D000328:Adult; D000650:Amnion / Q000276:immunology* / Q000648:ultrastructure; D015703:Antigens, CD / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007633:Keratins / Q000276:immunology; D011247:Pregnancy; D014327:Trophoblasts / Q000276:immunology* / Q000648:ultrastructure
D015703:Antigens, CD; D007633:Keratins