Insulin autoantibodies as markers of potential diabetes mellitus.
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Adult↗
Biomedical subjects
R Zanchetta
Publications and source records attributed to R Zanchetta.
Changes in the organization of the extracellular matrix in ovarian follicles during the preovulatory phase and atresia. An immunofluorescence study.
The distribution of laminin, type IV collagen and fibronectin was studied by immunofluorescence in rat, pig and cow ovarian follicles. The results obtained in the three species investigated were similar. In all the follicles, laminin and type IV collagen were identically localized in the basal lamina (BL) separating the granulosa and the theca layers. In addition, these two proteins were also distributed in the wall of blood vessels of the thecae and ovarian stroma. The staining showed that the BL of primordial and growing follicles was regular and continuous, but underwent striking modifications during ovulation and atresia. In fact, in preovulatory follicles the BL appeared thinner and discontinuous, whereas it was much thickened and ruptured in atretic follicles. Fibronectin was localized mainly in inner granulosa cells of small and medium-sized growing follicles, and as a broad and irregular layer around the cavity of the degenerated follicles. The results show that each stage of follicular growth and involution is associated with a precise and peculiar pattern of distribution of laminin, type IV collagen and fibronectin. The possibility that these proteins play a role in the local control of ovarian follicular dynamics is advanced.
Animals↗
Islet cell and insulin autoantibodies in organ-specific autoimmune patients. Their behaviour and predictive value for the development of type 1 (insulin-dependent) diabetes mellitus. A 10-year follow-up study.
To evaluate the behaviour and predictive value of islet cell and insulin autoantibodies in patients with organ-specific autoimmune diseases, we followed 21 non-diabetic subjects for a mean period of 84 +/- 27 months. Ten patients were persistently seropositive for complement-fixing islet cell antibodies and high titres of immunoglobulin G islet cell antibodies (greater than or equal to 1:8). The prevalence of persistent insulin autoantibodies in this group was 67%. Seven patients (70%) developed Type 1 (insulin-dependent) diabetes mellitus after a latency period of 2-60 months. The predictive value of complement-fixing islet cell antibodies was 65%, and in the presence of both complement-fixing islet cell and insulin autoantibodies the predictive value rose to 76%. Eleven patients were seronegative for complement-fixing islet cell antibodies and had low immunoglobulin G islet cell antibodies titres (less than 1:8) that were either persistent or transient, or that fluctuated during follow-up. The prevalence of persistent insulin autoantibodies in this group was 45%; only one subject developed Type 1 diabetes. The predictive value of persistent islet cell antibodies (complement-fixing positive/negative) was 54%, and it rose to 70% when both islet cell and insulin autoantibodies were present. Individuals with only insulin autoantibodies or immunoglobulin G islet cell antibodies did not develop diabetes mellitus. A high frequency of HLA-DR3 and/or DR4 was found in patients who developed diabetes mellitus. Thus, the presence of both islet cell and insulin autoantibodies in patients with organ-specific autoimmune disease appears to confer the highest risk of progression toward Type 1 diabetes.
Adolescent↗
A new ELISA method for the detection of serum bindable anti-platelet antibodies (SPBIG).
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Autoantibodies↗
Sperm antibodies and infertility in patients with testicular cancer.
The level of antisperm antibodies using the enzyme-linked immunosorbent assay (ELISA) in the serum of 48 patients with testicular cancer before and after therapy is reviewed. This is not a linear study of each patient, but some conclusions can be drawn: In a high percentage of testicular cancer patients serum antisperm antibodies can be detected: 73.3 per cent before orchiectomy and 43.7 per cent overall. The percentage of patients with antibodies decreases with adequate therapy. In patients with advanced disease there is a higher percentage of positivity (50%) for serum antisperm antibodies than in patients with low-stage disease (30%). The higher percentage of antibodies-positive patients among those with infertility patterns could be an important argument that supports the hypothesis that autoimmune pathology can play a role in oligo/azoospermia in testicular cancer patients.
Adolescent↗
The effect of Mycoplasma hominis and Ureaplasma urealyticum on hamster egg in vitro penetration by human spermatozoa.
The effects of some genital mycoplasmas on the in vitro penetration of human spermatozoa into the master egg were studied. Ureaplasma urealyticum serotypes 4, 8, and 6 showed high interfering activity: 6.3% (P less than 0.01), 12.3%, and 14.5%, respectively, against the 55.6% penetration rate of untreated sperm. Neither a cytotoxic effect of mycoplasmas on gametes nor a masking of the binding sites on the egg surface were demonstrated. In experiments carried out with U. urealyticum serotype 4, the production of diffusible relatively heat-labile factor(s) responsible for the inhibition of sperm penetration was postulated.
Animals↗
Elevated antisperm antibodies in patients with testicular cancer: is there a relationship with infertility?
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Adolescent↗
Mycoplasmic localization patterns on spermatozoa from infertile men.
Two mycoplasmas have been observed with increasing frequency in patients with genitourinary disorders: Mycoplasma hominis and Ureaplasma urealyticum. Mycoplasma cells of both these species have been demonstrated to be capable of attaching to human spermatozoa of infertile patients. The mechanisms for the association of infertility and mycoplasma infection have not been established. The main objective of this article was to explain the significance of some morphologic features of spermatozoa of patients with unexplained infertility using light and electron microscopy. These studies and quantitative analysis of ureaplasmas in the semen indicate that at least two patterns can be seen. Frequently, sphere-shaped particles adhering mainly to the midpiece of spermatozoa were detected. In a second, more complex pattern ureaplasmas were seen inside a swollen zone on the midpiece, which suggests that the infection does not occur in the urethra, but at another unknown site. Furthermore, the sphere-shaped particles cannot be associated with ureaplasmas because their titers in the semen of infertile patients were much lower than those expected.
Adult↗
A simplified method using enzyme-linked immunosorbent assay for titration of antisperm antibodies.
We selected sera from 44 patients (36 males and 8 females) that were positive for antisperm antibodies using ELISA (titer ranged from 1:32 to 1:512) for the evaluation of a simplified method for determination of antisperm antibodies. This method uses a correlation between a single absorbant value and the endpoint titer of the same serum. This simplified procedure increases the number of the sera that can be tested on each plate, resulting in considerable saving of time, reagent costs, and materials. A standard curve allows the direct determination of endpoint titer using the absorbance value found at a single dilution. This modification improves the utility of the assay for the epidemiological screening of antisperm antibodies in patients who may have an immunological cause of infertility.
Adult↗
A microplate enzyme-linked immunospecific assay (ELISA) detecting unbound anti-platelet antibodies.
A microplate immune-enzymatic method was developed for detecting serum antiplatelet antibodies. The method involves the use of antigen-coated platelets and alkaline phosphatase-labeled antihuman immunoglobulin. Linear correlation was obtained between the titer of platelet antibodies and substrate conversion. Twenty-four patients with immune thrombocytopenia and 40 normal controls were studied. Eighteen patients and one control were positive. Therefore, sensitivity and specificity were 75% and 97% respectively. ELISA also was found to be more sensitive than the indirect antiglobulin consumption assay (ACA) and appears to be a practical and easy method for routine evaluation of antiplatelet antibodies.
Binding Sites, Antibody↗
Autoantibodies against Leydig cells in patients after spermatic cord torsion.
This study is aimed at searching for the presence of circulating antibodies against frozen sections of human testis, ovary and trophoblast in patients that had spermatic cord torsion. Sixty-eight sera samples were studied. Nine patients (13.2%) were positive for organ specific anti-testis autoantibodies. Six patients were positive for antibodies against Leydig cells: five were positive only with the indirect immunofluorescence technique of complement fixing (ITT/CF), the sixth patient was positive only with the indirect immunofluorescence technique (ITT). The other three patients were positive for antibodies against germ line cells: two patients were positive with both techniques, the third was positive only with indirect immunofluorescence technique. Eight of these patients were negative for antibodies against adrenal cortex while only one case was positive with indirect immunofluorescence technique both on adrenal cortex and Leydig cells. Human lyophilized testis absorbed the reactive antibodies against Leydig cells and germ line cells, while adrenal cortex and lyophilized testosterone were ineffective. This study shows the identification of a specific antibody against Leydig cells and germ line cells in patients after spermatic cord torsion.
Adolescent↗
Do mycoplasmas inhibit the human sperm fertilizing ability in vitro?
Although clinical observations have suggested that Ureaplasma urealyticum may be associated with reproductive failure, the role of ureaplasmas in human infertility remains controversial. However, the mechanism whereby ureaplasmas can interfere with the fertilization process is not known. To study possible mechanisms, we used the human sperm-hamster egg fertilization test. Eggs were exposed to the spermatozoa preincubated with Mycoplasma hominis or U. urealyticum (serotype 1-8). U. urealyticum serotype 4 showed greater interference activity on the penetration rate (6.6%) than did the other mycoplasmas, as compared with the control (55%). Furthermore, our data suggest that the inhibition of penetration was not related to a masking of sperm membrane sites, since the mean of adsorbed spermatozoa/egg after preincubation of spermatozoa with mycoplasmas was not significantly different from that of the control. In addition, eggs preincubated with U. urealyticum serotype 4 gave a reduction of the penetration rate by untreated spermatozoa.
Adsorption↗
Complement-fixing adrenal autoantibodies as a marker for predicting onset of idiopathic Addison's disease.
In a prospective investigation of the role of adrenal autoantibodies (AA) in predicting the onset of idiopathic Addison's disease, 9 initially non-addisonian AA-positive autoimmune subjects were followed for 42 months. In 4 of these subjects Addison's disease developed within 1-31 months. A fifth had reduced adrenocortical reserve at the start and at the end of the investigation. An AA capable of fixing the membrane attack complex of complement [(C5-C9) F-AA] was detected before onset of the disease in the sera of the 4 patients in whom Addison's disease developed. (C5-C9) F-AA may be involved in the pathogenesis of idiopathic Addison's disease and may be regarded as a marker for individuals in whom idiopathic adrenal insufficiency is likely to develop.
Addison Disease↗
Pathogenesis of persistent infertility in men after varicocelectomy.
With a view to investigating the cause of persistent infertility, the authors studied a group of 27 patients who had, previously, undergone surgical ligation of the spermatic vein for varicocele and infertility. Of these subjects, who failed to father after surgery, 12 presented persisting varicocele at the clinical examination. In 6 cases, the seminal fluid was positive for U. Urealyticum. One patient had orchiepididymitis; in one spermioagglutinating antibodies were found, in one the female partner was found to be infertile. Even preoperatively, three subjects had pathologically high gonadotropin levels, an important sign of testicular parenchyma alteration. In three subjects only there were no pathological findings to explain persistent infertility.
Adult↗
The enzyme-linked immunosorbent assay for detection of the antispermatozoal antibodies.
An immune-enzymatic method was developed for the determination of antispermatozoal antibodies. Sera of 94 infertile patients were studied with the enzyme-linked immunosorbent assay (ELISA). Twelve patients were positive for antispermatozoal antibodies. Forty-six of these patients were studied also with the gelatin agglutination test (GAT). Eight sera were positive in the ELISA and nine in the GAT. With ELISA, immunoglobulin classes can be demonstrated; in fact, nine of our patients were positive for IgG and three for IgM. In all patients the IgA titer was less than 1:16. In addition, 61 seminal fluid specimens were studied by ELISA, and 7 were positive. The serum and seminal fluid of 12 patients were simultaneously studied. Seminal fluid was positive in only three patients, serum was positive in four, whereas serum and seminal fluid were both negative in five. This study illustrates that ELISA is apparently less sensitive than GAT; however, it is certainly more practical and an easier method for antibody research in sera and in seminal fluid.
Agglutination Tests↗
Assessment of adrenocortical function and autoantibodies in a baby born to a mother with autoimmune polyglandular syndrome Type 2.
We describe the case of a baby born to a mother with Addison's disease in the context of Autoimmune Polyendocrine Syndrome Type 2. Adrenal cortex autoantibodies and steroid 21-hydroxylase autoantibodies were detectable in the sera of both mother and baby, suggesting the transplacental passage of these autoantibodies. Adrenal autoantibodies were present in the baby's serum at delivery, at 3, 6 and till 34 months of age but no signs of clinical or subclinical adrenal insufficiency were found in the baby during the observation period. These data suggest that the presence of adrenal autoantibodies in serum alone is not a sufficient cause for the development of autoimmune adrenalitis.
Addison Disease↗
Immunological and clinical study of patients after spermatic cord torsion.
We studied 25 patients with spermatic cord torsion occurring after puberty. The elapsed time between the onset of symptoms and observation varied from 6 months to 7 years. We evaluated the semen of these patients and found that the number of spermatozoa was lower in patients with an atrophic testis (13 patients) than in those with a normal testis or, in those with torsion treated by orchidectomy. Moreover, the number of spermatozoa was lower in patients who had torsion for more than 2 years before being checked (12 patients) than in patients who had a more recent torsion (13 patients). Agglutinating antibodies were present in 20% of the patients but, they are not correlated fertility or sterility. Immunofluorescent antibodies also were not correlated with the changes found by semen analysis. They are not present in patients with a normal testis at the time of observation. On the other hand, immobilizing antibodies were significantly correlated with sterility and, particularly with changes of motility. These data suggest that sterility after spermatic cord torsion is correlated with an autoimmune mechanism. It may occur particularly in those patients with atrophic testes and has a slow onset taking more than 2 years to evolve completely.
Adolescent↗
Histological study of the removed testes of patients after acute monolateral spermatic cord torsion.
Infertility is frequent in patients after spermatic cord torsion usually when the twisted testis is not removed and becomes atrophic. The mechanism seems to be autoimmune. To see if the atrophic testis may be the source of antigens we carefully examined the histology of atrophic testis of 6 patients. The two patients that had spermatic cord torsion more than 3 years before surgical removal did not show recognizable testicular structures while the other patients that had spermatic cord torsion less than 1 year still showed some spermatogonia in the tubules and some spermatozoa in the epididymis. We think that the surgical removal of the atrophic testis after more than 1 year from the acute episode is of doubtful utility for preventing or blocking the autoimmune phenomenon because testicular antigens are absent and the autoimmune mechanism is able to maintain itself.
Acute Disease↗