Influence of estrogens on vascular transudation and mucus production in the rabbit endocervix

The manner in which estrogens mediate cyclical changes in the viscoelastic properties and volume of cervical mucus is unclear. To identify the response to estrogens of each of the major mucus components (mucin[s], soluble proteins, and small electrolytes and water), the authors quantitated their accumulation rates before and during estrogen stimulation in the rabbit. Circulating radiolabeled markers (35S-sulfate and 131I-albumin) were used to monitor the incorporation of small and large molecular weight intravascular substances into the cervical mucus. The accumulation rate of mucins was unaffected by exogenous estrogen administration, despite significant increases in mucus volume. This increase in mucus volume was attributed to a significantly increased transudation of water and small electrolytes increasing mucus hydration as early as the first 2 hours of estrogen administration. Water, small electrolytes, and soluble proteins significantly increased during the third and fourth hours of estrogen administration, not only when compared with the unstimulated basal levels, but also when compared with the levels found during the first 2 hours of estrogen administration. No significant change occurred in mucin production, while significant changes occurred in the accumulation of proteins and small electrolytes, whether estrogen was given initially or terminally in the experiment protocol.

Patterns of increase in serum estradiol in response to ovarian stimulation and their relationship to oocyte fertilization and cleavage in vitro

The in vitro fertilization and cleavage rates of oocytes obtained from patients exhibiting two different patterns of increase in serial serum concentrations of estradiol (E2) in response to ovarian stimulation were compared. Forty-two cycles (from 38 stimulated patients) were evaluated because they fulfilled requirements from two pre-defined patterns of E2 response to ovarian stimulation. In 16 cycles, serial serum E2 concentrations followed a "plateau" pattern (group A), viz., the rate of increase in the serum concentration of E2 decreased prior to the administration of human chorionic gonadotropin (hCG). In 26 cycles, serial serum E2 concentrations followed a "leap" pattern (group B), in which the rate of increase in serum concentrations of E2 increased progressively up to and including the day of hCG administration. There was no significant difference in the fertilization rate of oocytes obtained from patients exhibiting either pattern A or pattern B (78 versus 74%) but the cleavage rate was significantly higher in ova obtained from patients who exhibited pattern A rather than pattern B (72 vs 50%; P less than or equal to 0.01). In addition, embryos resulting from fertilized ova obtained from women in group A were of better quality morphologically than those obtained from women in group B (mean embryo grades, 3.9 vs 3.2; P less than or equal to 0.005). We conclude that cycles in which serial serum concentrations of E2 follow pattern A in response to stimulation give rise to oocytes that, when fertilized, yield higher cleavage rates and better-quality embryos than oocytes obtained from women in whom serial serum E2 concentrations follow pattern B.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of 125I-concanavalin A-labeled plasma membrane from unfertilized mouse eggs

A procedure was developed for isolation of plasma membrane (PM) preparations from unfertilized mouse eggs. Zona-free mouse eggs prepared by the method of Boldt and Wolf (Gamete Res 13:213-222, 1986) were labeled with 125I-concanavalin A (ConA) prior to sonication and fractionation on iso-osmotic self-generated Percoll density gradients. Experiments using the ConA-specific sugar alpha-methylmannoside (alpha MM) indicated that 125I-ConA bound specifically to the egg PM. Greater than 95% of 125I-ConA binding to zona-free eggs was blocked in the presence of 0.1 M alpha MM, and incubation of eggs in alpha MM after 125I-ConA labeling caused release of 85-90% of bound label. Fractionation of 125I-ConA-labeled eggs by Percoll density gradient centrifugation yielded a single radioactive peak at density = 1.025, corresponding to egg PM material. Prolonged incubation of 125I-ConA-labeled eggs or egg sonicates prior to fractionation did not alter the location of the radioactive peak, indicating that 125I-ConA did not label other organelles. As a control, human erythrocytes were labeled with 125I-ConA and fractionated under identical experimental conditions and yielded a single radioactive peak at density (1.020) comparable to that observed for 125I-ConA-labeled eggs. These results indicate that 125I-ConA can be used as a specific marker to support PM isolation from small numbers of zona-free mouse eggs.

Intermediate filament proteins in human sperm heads

Monoclonal antibodies made against human sperm cells have been characterized with regard to binding patterns and molecular coordinates of the recognized antigens. Antibodies T5 and T6 gave uniform binding to the acrosomal cap in an intact cell, and decreased to equatorial segment binding in an 'acrosome-reacted' cell. Monoclonal antibody T15 gave the reverse: equatorial segment binding in intact cells and uniform acrosomal cap binding in reacted cells. From staining patterns on cultured cell lines, determination of molecular coordinates, immunoblots, and partial peptide analysis, we have determined that T15 is directed against the cytoskeletal protein, vimentin, while T5 and T6 recognize a keratin-like protein which may be unique to sperm cells. This is the first immunological and biochemical study to analyse both types of intermediate filament proteins in human sperm cells.

Undetected ovulation in in vitro fertilization-embryo transfer patients

A retrospective evaluation was done of 102 consecutive in in vitro fertilization-embryo transfer (IVF-ET) treatment cycles that culminated in surgical intervention for oocyte pickup. In 35% of these patients, a disparity was noted in the number of mature follicles present on the day of human chorionic gonadotropin administration, compared with the day of surgery. This suggests the occurrence of undetected ovulation. An endogenous luteinizing hormone (LH) surge was detected in 14 of these patients. Another cohort showed evidence of early luteinization without a detected endogenous LH surge. Finally, a group without early luteinization was defined. Possible explanations for these outcomes and the implications for success of IVF-ET are discussed.

Patterns of estradiol response in patients with endogenous gonadotropin surges during follicular recruitment in an in vitro fertilization and embryo transfer program

This report is an analysis of 16 cycles in 15 patients stimulated with human menopausal gonadotropin and clomiphene citrate for the purpose of follicular recruitment in an in vitro fertilization program, all of which resulted in endogenous luteinizing hormone (LH) surges. A study of the pattern of estradiol (E2) response to stimulation revealed two groups of cycles, designated "leap" pattern (9 cycles) and "plateau" pattern (7 cycles), the rate of rise of E2 increasing or decreasing, respectively, as the time of the LH surge was approached. There were no significant differences between these groups of cycles in the peak E2 level attained or the number of follicles greater than or equal to 12 mm on the day of peak E2. In the plateau, but not in the leap pattern cycles, a significant correlation (r = 0.958) was found between the number of follicles greater than or equal to 12 mm and the peak E2. We tentatively conclude that "plateau" pattern cycles reflect relatively synchronous follicular recruitment; the greater the number of follicles recruited, the higher the E2 level attained, increased amounts of inhibin-like substances being available to restrain the LH surge; "leap" pattern cycles reflect asynchronous follicular recruitment.

Acrosomal status in fresh and capacitated human ejaculated sperm

The acrosomal status of human sperm was evaluated by immunofluorescence utilizing a specific monoclonal antibody that recognizes target antigen(s) localized in the acrosomal cap region. Spontaneous acrosomal loss was first examined in sperm preparations used for successful in vitro fertilization of human eggs. In these sperm populations, less than 20% of the sperm underwent degenerative or spontaneous acrosomal loss following 24 h of incubation. The correlation of acrosomal loss with changes in motility and viability suggested that sperm senescence was not necessarily coupled to acrosomal loss. Chemical induction of acrosomal loss by calcium ionophore A23187 and lysophosphatidylcholine (LPC) was characterized. Maximal ionophore induction (10 microM A23187 in media containing calcium) was observed in cells exposed to capacitating conditions in vitro; sperm exposed to noncapacitating conditions did not readily acquire the ability to respond to ionophore. The reaction induced by ionophore was slow (60 min), and at least 30% of the cells were always resistant to induction. In contrast, LPC induced rapid, synchronous acrosomal loss in either freshly ejaculated or capacitated sperm in the presence or absence of extracellular calcium, suggesting that this loss was not a physiologic reaction. These studies may provide a basis for evaluating capacitation and ultimately fertility potential in the human male.

Characteristics of patients with and without gonadotropin surges during follicular recruitment in an in vitro fertilization/embryo transfer program

Fifteen ovulatory patients undergoing ovarian stimulation with clomiphene citrate-human menopausal gonadotropin-human chorionic gonadotropin (hCG) for in vitro fertilization were studied. All 15 attained peak estradiol (E2) levels of greater than 600 pg/ml. Eight patients had an endogenous luteinizing hormone (LH) surge before the administration of hCG. The characteristics of these "surge" patients were compared with those of the remaining seven "nonsurge" patients. There was no significant difference in the peak morning E2 achieved before hCG or the endogenous LH surge, nor in the peak absolute increase in E2 over a 24-hour period in these two groups. The surge group had significantly higher E2 levels per follicle greater than or equal to 15 mm, measured by ultrasound on the morning of the day of administration of hCG or the LH surge (P less than or equal to 0.005). In addition, nonsurge patients had a greater number of follicles greater than or equal to 15 mm, compared with surge patients (P less than or equal to 0.05). It is hypothesized that greater quantities of nonsteroidal hormones, such as inhibin, produced by a greater number of preovulatory follicles in nonsurge patients, may block the pituitary response to hypothalamic gonadotropin-releasing hormone in the face of high and rising E2 levels.

Research frontiers in human in vitro fertilization

The acceptance of IVF-ET as a treatment modality for certain types of infertility in the human has triggered a flurry of activity in providing a patient service, in applied research endeavors designed primarily to improve clinical pregnancy rates and in basic research in reproductive endocrinology and physiology. This paper outlines the state of the art in technologic and research frontiers associated with these endeavors.

Actin in ejaculated human sperm cells

Previous studies have identified an "actin-like" protein in human sperm by indirect immunofluorescence microscopy with various probes, but no real biochemical confirmation of actin was made. In this study, two-dimensional (2-D) gels of Nonidet P-40 (NP-40) extracts of purified human sperm cells revealed a protein with appropriate pI and molecular weight coordinates for actin. When excised from a 2-D gel, cleaved with N-chlorosuccinimide, and separated on a sodium dodecyl sulfate slab gel, this putative actin showed a cleavage pattern identical to those from known actin. Furthermore, when sperm were immediately purified from whole semen and extracted with 0.3% NP-40, actin was detected almost entirely in the soluble fraction, indicative of unpolymerized actin. Conclusions from these experiments support those implied by direct immunofluorescence microscopy: actin is present in human sperm and appears to be mainly unpolymerized.

Acrosomal status evaluation in human ejaculated sperm with monoclonal antibodies

An important question in mammalian gamete physiology concerns how capacitation and the occurrence of acrosome reactions in motile sperm relate to fertility. Evaluation of these relationships has been restricted by practical limitations because rapid, quantitative assays are unavailable. We have developed a rapid, reproducible assay for the evaluation of acrosomal status utilizing monoclonal antibodies specific to antigens localized in the acrosomal cap region of the sperm head. Mice were immunized with human ejaculated sperm preparations and the resultant hybridomas producing antisperm antibody were selected by solid-phase radioimmunoassay and indirect immunofluorescence (IIF). Two monoclonal antibodies (HS-19, HS-21) recognized target antigens restricted to the acrosomal cap by IIF, and 87 +/- 8.5% of the sperm in fresh ejaculates from 10 different sperm donors showed positive cap fluorescence with these reagents. Loss of HS-21 binding as measured by IIF was correlated with disappearance of the acrosomal cap as observed directly by transmission electron microscopy. Acrosomal disappearance, artificially induced in vitro using the calcium ionophore A23187, also resulted in a loss of HS-21 binding. The induction of acrosomal loss by ionophore was dependent upon extracellular calcium. The data presented suggest that specific monoclonal antibodies can be used for the rapid evaluation of acrosomal status in mammalian sperm.

Preliminary experience with a combination of clomiphene and variable dosages of menopausal gonadotropins for enhanced follicular recruitment

A combination of clomiphene citrate and human menopausal gonadotropin was employed for enhanced follicular recruitment in an in vitro fertilization program. All patients received 50 mg of clomiphene and 1 ampule of human menopausal gonadotropin daily from cycle day 5 through cycle day 9. Follicular monitoring was begun on day 10 using a combination of ultrasound measurement of follicular size and number and determination of peripheral estradiol levels. Based on the size and number of follicles, the peripheral levels of estradiol, and the rate of follicular growth and increase in estradiol, human menopausal gonadotropin was continued at a dosage of 1 to 3 ampules/day through the day of human chorionic gonadotropin administration. Human chorionic gonadotropin was administered on the evening of the day the largest follicle reached or exceeded 20 mm in mean diameter if the estradiol levels had been rapidly rising or reaching a plateau and had exceeded a minimal level of 300 pg/ml. Using this protocol, 30 of 33 patients underwent laparoscopy, 29 patients had successful oocyte recovery, and 23 patients underwent embryo replacement, with the establishment of six clinical pregnancies.

Albumin-mediated changes in sperm sterol content during capacitation

The role of albumin in mouse sperm capacitation was studied in relation to its activities as a lipid-solubilizing protein and a sterol acceptor. Two bovine serum albumins (BSA) which supported capacitation, Fraction V and fatty acid-free, both contained cholesterol and phospholipid but were without detectable levels of serum high-density lipoprotein (HDL). The lipid content of BSA could be reduced by trichloroacetic acid (TCA) precipitation; however, removal of all detectable lipids required precipitation with ethanolic acetone and diethyl ether extraction. In medium supplemented with Fraction V, fatty acid-free, or TCA-precipitated BSA, mouse sperm were capacitated as evidenced by their ability to fertilize eggs, concomitant with decreases in total cellular sterol and increases in phospholipid content. Delipidated BSA, fractionated on Sephadex G-100 in guanidine HCl also supported capacitation and mediated a 20% decrease in sperm sterol content, while cellular phospholipid levels remained unchanged. When BSA was modified by cholesterol augmentation, fertilization was inhibited in a cholesterol dose-dependent manner. These findings suggest that modulation of sperm lipid levels comprises an event of capacitation and that albumin mediates this process through its activity as a sterol acceptor.

Sperm concentration and the fertilization of human eggs in vitro

The effect of sperm concentration on the fertilization of preovulatory and immature human eggs was studied in the context of an ongoing in vitro fertilization-embryo transfer (IVF-ET) program. Fertilization success was independent of the follicular recruitment protocol used, and with preovulatory eggs, was inversely related to sperm concentration over the range of 2.5 - 50 X 10(4) motile sperm/ml. Maximum fertilization (80.8%) occurred at a concentration of 2.5 X 10(4) motile sperm/ml. The incidence of polyspermic fertilization was directly related to the sperm concentration, decreasing from 5.5% at 10 X 10(4) to 0% at 1-2.5 X 10(4) motile sperm/ml. Immature eggs cultured in vitro, then inseminated, also demonstrated an inverse relationship between fertilization and sperm concentration with a maximum fertilization rate of 66.6% at 5 X 10(4) motile sperm/ml. The percentage of motile sperm in the inseminating population had no influence on fertilization rates unless the value dropped below 40%. Fertilization success using sperm from oligospermic and polyzoospermic males was also examined. In contrast to males with normal semen parameters, oligospermic males demonstrated highest fertilization success at 50 X 10(4) motile sperm/ml. The IVF of preovulatory eggs using sperm from polyzoospermic males was comparable to that for males with normal semen parameters at equivalent sperm concentrations. The implications of these findings to the application of IVF-ET technology to the infertile couple is discussed.

Enhanced follicular recruitment in an in vitro fertilization program: clomiphene alone versus a clomiphene/human menopausal gonadotropin combination

In an attempt to improve the pregnancy rate following in vitro fertilization and embryo transfer by increasing the numbers of embryos available for transfer to each patient, a prospective, randomized comparison of clomiphene citrate alone (50 mg/day, cycle days 5 to 9) with the combination of clomiphene as above plus human menopausal gonadotropin (2 ampules/day, cycle days 6, 8, and 10) was undertaken from January through April 1983, with 17 patients in each group. The combination produced increased follicular development, compared with clomiphene alone, resulting in the retrieval of more fertilizable oocytes. Two clinical pregnancies resulted in each group. These results show that a fixed combination of clomiphene and human menopausal gonadotropin produces a greater degree of enhanced follicular recruitment, resulting in the recovery of an increased number of fertilizable oocytes. The lack of a statistically significant increase in the number of embryos transferred per patient in the combination group as well as the identical number of clinical pregnancies in both groups suggests that this particular combination of clomiphene and human menopausal gonadotropin offers no advantage over the use of clomiphene alone for enhanced follicular recruitment.

Clomiphene citrate in an in vitro fertilization program: hormonal comparisons between 50- and 150-mg daily dosages

When clomiphene citrate is used for enhanced follicular recruitment in an in vitro fertilization and embryo transfer program, the usual dosage is 150 mg/day, although we recently reported comparable follicular development (size and number) with 50 mg/day. The present report compares circulating hormone levels between groups of patients receiving the two regimens. Gonadotropin levels were higher in the 150-mg group throughout the follicular phase. Serum estradiol (E2) levels, expressed either as total E2 or E2 per follicle greater than or equal to 15 mm, were also higher throughout the follicular phase in the 150-mg group. During the luteal phase, the progesterone levels were similar in both groups. However, there were higher E2 levels in the 150-mg group during the entire luteal phase. Even though there were no significant differences between groups with regard to the degree of enhanced follicular recruitment, there were significant differences in the observed hormone levels.

Human in vitro fertilization and embryo transfer at the University of Texas, Houston

The current clinical and laboratory protocols of the in vitro fertilization program at the University of Texas at Houston are described and detailed. Most patients treated have tubal disease, with a limited number of couples having male factors. Clomiphene citrate (50 mg/day, cycle days 5-9) with or without added menopausal gonadotropins is the principle agent for enhanced follicular recruitment. Follicular development is monitored primarily with daily ultrasonography, and human chorionic gonadotropin (hCG) is given when the largest follicle reaches or exceeds 20-mm mean diameter. The culture media used are modifications of Ham's F-10. Mature oocytes are preincubated for 5 hr before insemination with 50,000 motile sperm per oocyte. Using these protocols, the clinical pregnancy rate is 11.6% per laparoscopy (11/95) and 16.2% per embryo transfer (11/68).

Characterization of human sperm surface antigens with monoclonal antibodies

Monoclonal antibodies (McAb) against human ejaculated sperm were developed from mice immunized with sperm membrane preparations. A solid-phase radioimmunoassay, with dried sperm as antigen, was employed in McAb screening. The tissue and species specificity of monoclonal antibodies HS 2, 4 and 6 were evaluated after absorption of antibody preparations with heterologous sperm, human serum or seminal plasma or cells from other human organs. The sensitivity of HS 2, 4 and 6 antigens to trypsin exposure was determined: HS 4 antigen was highly sensitive while HS 2 and 6 were not. The regional distribution of McAb 4 on intact sperm cells was determined by immunofluorescence staining. HS 4 may be a sperm-coating antigen based on its presence on sperm and in seminal plasma. This possibility led to an investigation of its role in sperm capacitation. HS 4 antibody binding was reduced when capacitated sperm were compared with noncapacitated cells. HS 4 antibody, when present during capacitation and insemination, was without effect on sperm motility or fusion with zona-free hamster eggs. Trypsin removal of as much as 60% of HS 4 antigen from the cell population also did not impact on sperm function. To identify the molecular correlate of HS 4 antigen, membrane components were extracted from washed sperm with Nonidet P-40, concentrated by acetone precipitation and analyzed electrophoretically in SDS-urea on 10% polyacrylamide slab gels. Immunoassays on protein blots with peroxidase-coupled second antibody identified a single reactive species in the molecular weight range of 130,000. Multiple reactive components were detected in blot transfers of seminal plasma.

Comparison of two clomiphene citrate dosage regimens for follicular recruitment in an in vitro fertilization program

Clomiphene citrate (CC) (150 mg/day) is used in most clinical in vitro fertilization and embryo transfer (IVF-ET) programs to induce maturation of several preovulatory follicles rather than the one characteristic of the unstimulated cycle. This study examines whether a reduced dosage of CC will induce the maturation of a similar number of follicles. The advantage of the reduced dosage should be a decrease in the dose-dependent antiestrogenic effects of CC. Normally ovulating women undergoing treatment in an IVF-ET program received CC on cycle days 5 to 9. Thirty-six patients received 150 mg/day, and 60 patients received 50 mg/day. There were no significant differences between the groups in the number or the size of follicles as measured by ultrasonography on the day of human chorionic gonadotropin administration. All seven clinical pregnancies were in the 50 mg group (P less than 0.05). These data suggest that there is no advantage to the 150 mg/day dosage of CC as compared with 50 mg/day with respect to enhanced follicular recruitment, and the higher dosage may have a detrimental effect on pregnancy establishment.

Correlation of human in vitro fertilization with the hamster egg bioassay

We compared fertility potential measurements by the zona-free hamster egg bioassay with the in vitro fertilization of human eggs. Sperm from 24 husbands participating in an in vitro fertilization-embryo transfer program were used in 27 inseminations of the wives' eggs and in simultaneous inseminations of hamster eggs. In seven cases, a positive fertility assessment was obtained in the absence of fertilization of the wives' eggs attributable to egg immaturity or in one case to equipment failure. In the remaining 20 cases, at least one egg was fertilized, for a level of 73%. In 90% of the husbands who fertilized their wives' eggs, a positive fertility assessment was obtained. Two husbands gave false-negative assessments. To account for these, alternative culture conditions were examined; sperm exposure to longer preincubations or at higher concentrations usually improved assessments. These results indicate that fertility assessment with this bioassay is highly correlated with the fertilization of human eggs in vitro.

Absence of an electrical polyspermy block in the mouse

To examine the possibility of an electrical polyspermy block in the mouse, we recorded the electrophysiological properties of zona-free mouse eggs during fertilization. Starting from an unfertilized value of -41 +/- 4 mV (SD), the membrane potential undergoes an oscillation (seen in 8 of 11 records) of 4 +/- 1 mV in amplitude, starting 7 +/- 5 min after insemination, and lasting about 1 min. However, except for this small oscillation, the membrane potential is constant during the 60 min following insemination; the average range (11 +/- 4 mV) is not significantly different from that which is observed in 60-min recordings from unfertilized eggs. These results indicate that the polyspermy block which is established during this period (D. P. Wolf, 1978, Dev. Biol. 64, 1-10) is not electrically mediated. Consistent with this finding, reduction of the sodium or calcium concentration in the external medium does not induce polyspermy. As a consequence of fertilization, the resistance of the egg membrane decreases from 96 +/- 34 to 44 +/- 15 M omega; this change accompanies the voltage oscillation.

Follicular size and number in human in vitro fertilization

In an attempt to maximize the success of in vitro fertilization (IVF) and embryo transfer (ET) as a treatment for human infertility, we have examined the relationship of follicular size and number to the rates of oocyte recovery, fertilization, cleavage, and ET in clomiphene citrate-stimulated cycles. The recovery of oocytes from follicles less than 20 mm in diameter was significantly reduced over that from larger follicles, and those oocytes that were obtained from smaller follicles showed a significantly lower rate of fertilization and cleavage. In addition, the overall chance that a patient would undergo ET was greater in a cycle in which more than one follicle 20 mm or larger was developing than in a cycle in which a single large follicle was developing. This latter observation suggests that attempts at laparoscopic oocyte retrieval should be confined to cycles in which more than one accessible large follicle is developing, thereby maximizing the success rate while minimizing the risk and expense for the patient.

Sperm interaction with the zona-free hamster egg

The interaction of sperm with the zona-free hamster egg was studied. Hamster sperm were capacitated in Tyrodes media, containing 50% heat-inactivated serum and used to inseminate zona-free eggs in BWW containing 10% serum. Capacitated sperm began fusing with eggs within the first hour of insemination and by 3 h penetration had ceased as indicated by the absence of further changes in the mean number of sperm incorporated per egg. Penetration by capacitated hamster sperm was linearly related to the log of the motile sperm concentration at concentrations above 10(4) cells/ml. The viability of sperm and eggs in culture was limited in these studies to approximately 3-5 h. The existence of a block to unlimited sperm penetration of the zona-free egg was sought in reinsemination experiments. A relatively low sperm concentration was used to initiate egg responses, followed, at timed intervals, by reinsemination with a high challenge concentration of sperm. Subsequent polyspermy levels reflected the presence or absence of the egg's block to polyspermy response. In order to circumvent the problems arising from the rapid aging of hamster sperm in culture, mouse sperm were employed, a convenience afforded by the lack of species specificity in this egg. Reinseminated eggs incorporated additional sperm during the challenge; therefore, the hamster egg is not capable of preventing unlimited sperm penetration. The implications of these findings to the use of the zona-free hamster egg test in fertility evaluation is discussed.

Identification of antisperm antibodies on sperm of infertile men

An indirect radiolabeled antiglobulin test for plasma antisperm antibodies was modified so that sperm-associated antibodies could be identified. Ten of 16 (63%) infertile men with plasma IgG antisperm antibodies were found to have an elevated sperm-associated IgG. Two of these men with an elevated sperm-associated IgG also had an elevated sperm-associated IGA; one other man with plasma IgG antisperm antibodies, but no detectable sperm-associated IgG, was noted to have an elevated sperm-associated IgA. Eighteen infertile men with a history that suggested antibody-mediated infertility did not have plasma IgG antisperm antibodies; one (6%) of these men was found to have an elevated sperm-associated IgG; none of these 18 men were found to have an elevated sperm-associated IgA. No patient was found to have sperm-associated IgM.

Antibodies to sperm-associated antigens detected by solid phase assays

Solid phase assays using radiolabeled (RIA) or enzyme-linked (ELISA) antibodies are described for the quantitation of antibodies to sperm-associated antigens. Antibodies were detected in serum from rabbits immunized with human sperm emulsified in Freund's complete adjuvant and in the plasmas or sera of vasectomized males and patients with suspected antibody-mediated infertility. The RIA and ELISA assays are comparable to each other in sensitivity and specificity, rapid in execution, and inexpensive.