High levels of sperm-associated antibodies impair human spermoolemma interaction after subzonal insemination.
OBJECTIVE
To investigate the impact of sperm-associated antibodies in the fertilization process beyond the zona pellucida in human oocytes.


METHODS
Subzonal insemination (SUZI) was performed with antibody-coated spermatozoa from patients with autoimmune infertility. Sperm parameters and antibody binding were analyzed after Percoll selection and were compared with SUZI outcome.


METHODS
Patients (n = 29) with an immunobead test higher than 60% for immunoglobulin (Ig)G, IgA, or both classes were included in the study (38 attempts). Twenty-six patients had previous IVF failures, and the semen characteristics for three were unsuitable for IVF.


RESULTS
Diploid fertilization occurred in 52.6% of cycles and 16.0% of oocytes (n = 263). The fertilization rate was inversely correlated to the proportion of spermatozoa coated with IgG in the Percoll-selected sperm suspension. Three of the 16 attempts in which > 90% of the spermatozoa were coated with IgG resulted in a low diploid rate of 4.1%. Fertilization was obtained in 18 of the 22 attempts in which < 90% of spermatozoa were IgG coated, with a diploid fertilization rate of 22.8%. Association of both classes of antibodies (IgG and IgA) further impaired the fertilization rate. Twenty ETs gave four pregnancies: one biochemical, one ongoing, and two giving birth to healty babies (1 singleton and 2 twins).


CONCLUSIONS
Subzonal insemination is a potential solution for achieving fertilization in cases of IVF failure because of sperm autoimmunity. However, IgG inhibits in a dose-dependent manner the fusion of gametes' membranes. Though the level of IgA antibodies does not appear as critical as that of IgG antibodies, association of both classes of Igs impairs the probability of fertilization.
University of Paris XI, France.
J P
JP
Wolf
M
M
De Almeida
B
B
Ducot
D
D
Rodrigues
P
P
Jouannet
D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000276:immunology / Q000503:physiopathology*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007248:Infertility, Male / Q000276:immunology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009865:Oocytes / Q000502:physiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000276:immunology* / Q000502:physiology*; D017211:Treatment Failure; D016896:Treatment Outcome; D015044:Zona Pellucida / Q000502:physiology*
D007070:Immunoglobulin A; D007074:Immunoglobulin G