[Findings and significance of spermatozoa agglomeration in the semen]

Agglomeration of spermatozoa (pseudo-autagglutination, clumping of spermatozoa) is distinguished from agglutination in immunological processes by the coarse meshwork of the spermatozoa clumps and the central inclusion of epithelia, leukocytes, residual bodies, spermatozoa with persisting cytoplasmatic droplets, as well as parts of viscous seminal plasma. In 658 semen samples of out-patients with barried marriage, spermatozoa agglomerations were seen in 13.4% of the samples immediately after liquefaction while in additional 6.7%, they were found up to three hours later. The agglomeration phenomenon is typical but not specific of the so-called vegetative congestion syndrome, appearing concomitant with high spermatozoa counts, normal rate of spermatozoa motility and morphology, as well as an increase in residual bodies and spermatozoa with persisting cytoplasmatic droplets. Next to congestion syndrome, spermatozoa agglomerations may also result from post-inflammatory disturbances of epididymal or accessory gland function whereas in florid stages of inflammation, they are rarely observed. As the congestion syndrome may give rise to male infertility in some cases, andrologists should be acquainted with its clinical and spermatological symptoms with special regard to therapy.

Disc-electrophoretic protein pattern of cervical mucus in cases of humoral sensitization against spermatozoa

Midcycle cerevical mucus samples from 20 fertile women with negative, and from 6 infertile women with positive serum-sperm agglutinating activity were subjected to a qualitative protein analysis by the Ouchterlony-technique, to polyacrylamide (PAA) discelectrophoresis and after purification on spermatozoa they were also run against rabbit antihuman serum in the Laurell immuno-electrophoretic technique. By the Ouchterlony method the main serum protein fractions were shown to occur also in cervical mucus. No significant differences could be found in the protein pattern of samples from fertile and infertile females as detected by polyacrylamide (PAA) electrophoresis. In all samples a split protein fraction corresponding to serum albumin and a band preceding the protein fraction corresponding to serum preablumin were observed. In 2 samples from infertile females it could be demonstrated that immunoglobulins occurring in the cervical mucus were directed towards antigenic sperm components.

[Significance of proteolytic sperm enzymes for the fertility]

Proteolytic enzymes of the male genital tract have important functions in the reproduction process. The sperm enzyme acrosin is of particular significance for the penetration of the zona pellucida. Proteinases are involved in coagulation and liquefaction of human semen. The kallikrein-kinin system has an important role in stimulation and regulation of sperm motility. In addition, semen proteinases seem to be involved in the penetration and migration of spermatozoa through the cervix uteri. Disturbances of the proteolytic potential of human semen may be the cause of subfertility or infertility. Specific inhibition of proteinases participating in the fertilization process could be an approach for an effective antienzymatic contraception.

Difficulty of obtaining reproducibility in the Franklin and Dukes test for the detection of sperm-agglutinating antibodies in human sera

The Franklin and Dukes (FD) test is used as a screening test for the determination of sperm-agglutinating antibodies and as a proof of therapeutic effects in cases of infertility, but various parameters of the FD test remain unclear and the application of different techniques has revealed highly different results. To test the statistical evidence for the FD technique, conditions regarded as optimal prerequisites were applied: a sperm concentration of 20 times 10(6)/ml was produced with Baker's buffer and serum dilutions were made with Baker's buffer, starting at 1:4. Only the standard deviation of parallel tests with one serum sample and one semen sample on the same day was found to be within an acceptable range. Using ejaculates of the same donor and the same serum sample on different days gave results that were not reproducible. The FD test should not, therefore, be used for quantification of sperm-agglutination antibodies except for a comparison in one test with one semen sample on the same day. Although the FD test only allowed a qualitative evaluation of sperm-agglutinating antibodies the % sperm agglutination was more informative than agglutination titres. For quantification of sperm-agglutinating antibodies, the FD test should be replaced by other techniques.

Solubilization of human spermatozoa and antigen isolation responsable for agglutination

Spermatozoa were solubilized by cleaving the disulphide bonds with dithioerythrol and protecting the weak antigen responsable for spermagglutination with Na-dodecylsulphate. The fact that spermagglutinating activity could still be absorbed from female sera by solubilized spermatozoa indicates that the antigen has not been destroyed by the applied procedure. By gelelectrophoresis four fractions could be separated. Antibody fraction from four sera and three cervical mucus samples of women with humoral spermagglutinating antibody--activity were used as indicator antbodies in crossed immunoelectrophoresis of solubilized spermatozoa. As negative controls served four sera and two cervical mucus samples. A precipitation line could only be detected in positive cases. The second spermfraction of gel-electrophoresis was found to contain the antigen reacting with the known antibodies from the applied FD-positive sera and cervical mucus samples.

Autoimmunity to sperm antigens in vasectomized men

Sera from vasectomized men were tested for the presence of antibodies directed against sperm antigens. A high percentage (about 55%) of the vasectomized men developed agglutinating antibodies. A lower percentage (22%) also developed low titres of antibodies to human protamine, as detected in the indirect IFT on swollen sperm heads and 22% developed cytotoxic antibodies. A correlation was found between the presence of anti-protamine antibodies and the presence of agglutinating and of cytotoxic antibodies. This correlation, and also the fact that they developed after vasectomy, indicates that the formation of antibodies against human protamine is a result of an autoimmune response to spermatozoa. The indirect IFT was also performed on 'normal' unswollen spermatozoa. All the sera were positive at least on one of the sperm antigens located in the acrosome, equator, or post-nuclear region, but no increase nor decrease in titre was found after vasectomy.

Evaluation of human sera for antibodies against sperm by immunofluorescence

Newborn cord sera and sera from pregnant women and from couples with unexplained infertility were observed by indirect immunofluorescence for reactions against human sperm. The sera from the infertile couples had been tested for macro-agglutination and complement-dependent immobilizing antibodies as well. Nonspecific fluorescence was noted only on the quatorial segment. Acrosomes and tail end-pieces were strongly immunofluorescent (positive at a serum dilution of 1:16) with 60 to 70% and 30 to 50%, respectively, of the sera from each main group, with the exception of the nonreactive cord blood. End-piece fluorescence was primarily due to the IgM globulin fraction. It is suggested that cord serum anti-sperm antibodies, directed mainly against the tail main piece, are due to IgG passively acquired from the mother. There was no apparent difference in immunofluorescence between infertile patients and control groups (except for the acrosome and end-piece, with cord sera). However, when the sera from infertile patients were subdivided into groups containing only agglutinating antibody, only immobilizing antibody, and both types of antibody, a higher percentage of the sera from the group having only agglutinating antibody reacted with all sperm areas. This reaction seemed more uniform over the sperm and included the usually negative posnuclear cap and midpiece. The other subgroups showed no obvious trends.

[Autoantibody formation following voluntary vasectomy (author's transl)]

Serum autoantibodies were determined in 33 of 60 patients 3 to 24 months following a voluntary vasectomy. The macroscopic spermagglutination test according to the method of Kibrick and the immobilization test according the method of Isojima were used. Agglutination antibodies (titer greater than or equal to 1:2) were found in 55% of the patients with a maximal titer of 1:128. Titers from 1:32 were found in 6% of the cases. Immobilization antibodies (titer greater than or equal to 1:2) were found in 24% of the cases with titer values up to 1:16. There is no correlation between the antibody titers and the time of the vasectomy. There were no clinical indications of autoimmunological disease.

Antibodies to spermatozoa. V. Antibody activity in human cervical mucus

Efforts were made to seek sperm antibody activity in human cervical mucus (C.M.). A procedure of extraction was developed, as well as methods for measurement of total protein and of immunoglubulin level. The antibody testing was done by the Kibrick (K-B-M) and F-D methods. In clear contrast with negative control serum and negative C.M. samples, positive activity could be found in the C.M. extracts from several infertile women. Some of these manifestations were seen as positive K-B-M agglutination, whereas some were seen either as agglutination or immobilization in the F-D test; hence, three kinds of observation can be indicative of sperm antibody in extracts of cervical mucus.

Autoimmune human sperm antibodies and age in males

The incidence of autoimmunization to spermatozoa, investigated by means of the Kibrick technique, increased with age in 913 males unselected with regard to fertility. By contrast, the incidence of sperm agglutinin-postive sera decreased with age in 1600 male partners in sterile couples. The increasing incidence of autoimmunization to spermatozoa offers one explanation of the lowering of fertility with increasing age, but sperm antibodies seem to be more important as a cause of sterility at younger ages. The presence of spermatozoa may not be necessary for immunization since sperm agglutinins were found in a 9-year-old boy.

[Autoagglutinating sperm. One form of immunological male sterility]

The autoagglutination of sperm is an uncommon form of male sterility that must not, however, go unrecognized. Diagnosis of this condition is not always easy and in none of the 10 cases studied was the presence of agglutinins reported at the time of the first examination of the sperm. However, the inconsistency between a poor or negative post-coital test in a clear fluid and an apparently normal sperm count must be investigated. The idea of there being some connexion with allergic conditions in the patient or a close relative have often been discussed. By means of immunological techniques - which have not yet been thoroughly perfected in this field - it is usually possible to detect antibodies in the serum and sometimes also in the seminal plasma. In such cases the prognosis is not good as there is no effective therapy except in certain fortunate cases. One such case is reported.