Sources/Clones
Biogenesis and Serotec (R1, E4).
Fixation/Preparation
Antibodies to inhibin may be applied to paraffin-embedded tissues fixed in formalin but microwave pretreatment in citrate buffer is essential for optimum immunostaining.
Background
Inhibin is a peptide hormone produced by ovarian granulosa cells, which selectively inhibits the release of follicle-stimulating hormone (FSH) from the pituitary gland (McLachlan et al, 1987), acting as a modulator of folliculogenesis (Findlay 1993). Peak serum level is reached during the follicular phase of the menstrual cycle; being undetectable in the serum of menopausal women (LappØn et al, 1989). It is produced and overexpressed by granulosa cell tumors, thus being an early marker for tumor growth. Hence, its usefulness is as a marker of tumor recurrence before clinical manifestation (LappØn et al, 1989). Several inhibin subunits can be detected by immunostaining in the granulosa cell layers of the human ovary and in neighboring theca cells. Clone R1 was raised against a synthetic peptide corresponding to the 1-32 peptide of thea subunit of 32 kD human inhibin and reacts specifically with this molecule (Isotype: IgG2b) (Groome et al, 1990). Clone E4 was raised against a synthetic peptide corresponding to the 84-114 peptide sequence of theb A subunit of 32 kD human inhibin A and activin A (isotype 2b) (Groome and Lawrence, 1991). E4 reacts with both theb A and b B subunits of human inhibin and activin.
Applications
Using monoclonal antibody to human inhibin 32 kDa subunit, follicle epithelia in 6/6 samples of ovarian tissue (under 40 years), 6/6 adult granulosa cell tumors and three late metastases from granulosa cell tumors in females showed positive immunoreaction (Fleming et al, 1995). No reaction was found in hemangiopericytoma, leiomyosarcoma and malignant melanoma. This antibody would be useful in distinguishing the sarcomatoid growth pattern of granulosa cell tumors from soft tissue tumors. Further, no positive reaction was observed in ten ovarian carcinomas whilst in two of these cases, single cells of the specialized ovarian stroma stained positively with inhibin.
In another study inhibin immunostaining was also detected in stromal hyperthecosis, juvenile granulosa cell tumors and Sertoli-Leydig cell tumors (Stewart et al, 1997), proving that inhibin is a sensitive immunohistochemical marker of a wide range of gonadal stromal tumors. Strong cytoplasmic staining of 17/19 cases of hepatocellular carcinoma, including pleomorphic and glandular variants, has been demonstrated (McCluggage et al, 1997). In this study focal weak luminal staining of glands of adenocarcinoma was also present. Hence, immunostaining with antiinhibin antibody may be of value in the differentiation of hepatocellular carcinoma from adenocarcinoma involving the liver.
Comments
Inhibin antibody is useful in confirming the diagnosis of both adult and juvenile granulosa cell tumors, especially tumors with unusual growth patterns and in metastatic sites. It is also helpful in distinguishing hepatocellular carcinoma from adenocarcinomas in the liver.
References
•Findlay JK 1993. An update on the roles of inhibin, activin and follistatin as local regulators of folliculogenesis. Biology of Reproduction 48:15-23.
•Fleming P, Wellman A, Hansjâg Maschek, Lang H, Georgii A 1995. Monoclonal antibodies against inhibin represent key markers of adult granulosa cell tumors of the ovary even in their metastases. A report of three cases with late metastasis, being previously misinterpreted as haemangiopericytoma. American Journal of Surgical Pathogy 19: 927-933.
•Groome N, Lawrence M. 1991 Preparation of monoclonal antibodies to the beta A subunit of ovarian inhibin using a synthetic peptide immunogen. Hybridoma 10:309-316.
•Groome N, Hancock J, Betteridge A, Lawrence M, Craven R 1990. Monoclonal and polyclonal antibodies reactive with the 1-32 amino terminal sequence of the alpha subunit of human 32K inhibin. Hybridoma 9:31-42.
•Lappn RE, Burger HG, Bouma J, Bangah M, Krans M, De Brujn HWA 1989. Inhibin as a marker for granulosa-cell tumors. New England Journal of Medicine 321: 790-793.
•McCluggage WG, Maxwell P, Patterson A, Sloan JM 1997. Immunohistochemical staining of hepatocellular carcinoma with monoclonal antibody against inhibin. Histopathology 30: 518-522.
•McLachlan RI, Robertson DM, Burger HG, De Kretser DM 1987. Circulating immunoreactive inhibin levels during the normal menstrual cycle. Journal of Clinical Endocrinology and Metabolism 65:954-961.
•Stewart CJR, Deffers MD, Kennedy A 1997. Diagnostic value of inhibin immunoreactivity in ovarian gonadal stromal tumors and their histological mimics. Histopathology 31:67-74.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Biogenesis and Serotec (R1, E4).
Fixation/Preparation
Antibodies to inhibin may be applied to paraffin-embedded tissues fixed in formalin but microwave pretreatment in citrate buffer is essential for optimum immunostaining.
Background
Inhibin is a peptide hormone produced by ovarian granulosa cells, which selectively inhibits the release of follicle-stimulating hormone (FSH) from the pituitary gland (McLachlan et al, 1987), acting as a modulator of folliculogenesis (Findlay 1993). Peak serum level is reached during the follicular phase of the menstrual cycle; being undetectable in the serum of menopausal women (LappØn et al, 1989). It is produced and overexpressed by granulosa cell tumors, thus being an early marker for tumor growth. Hence, its usefulness is as a marker of tumor recurrence before clinical manifestation (LappØn et al, 1989). Several inhibin subunits can be detected by immunostaining in the granulosa cell layers of the human ovary and in neighboring theca cells. Clone R1 was raised against a synthetic peptide corresponding to the 1-32 peptide of thea subunit of 32 kD human inhibin and reacts specifically with this molecule (Isotype: IgG2b) (Groome et al, 1990). Clone E4 was raised against a synthetic peptide corresponding to the 84-114 peptide sequence of theb A subunit of 32 kD human inhibin A and activin A (isotype 2b) (Groome and Lawrence, 1991). E4 reacts with both theb A and b B subunits of human inhibin and activin.
Applications
Using monoclonal antibody to human inhibin 32 kDa subunit, follicle epithelia in 6/6 samples of ovarian tissue (under 40 years), 6/6 adult granulosa cell tumors and three late metastases from granulosa cell tumors in females showed positive immunoreaction (Fleming et al, 1995). No reaction was found in hemangiopericytoma, leiomyosarcoma and malignant melanoma. This antibody would be useful in distinguishing the sarcomatoid growth pattern of granulosa cell tumors from soft tissue tumors. Further, no positive reaction was observed in ten ovarian carcinomas whilst in two of these cases, single cells of the specialized ovarian stroma stained positively with inhibin.
In another study inhibin immunostaining was also detected in stromal hyperthecosis, juvenile granulosa cell tumors and Sertoli-Leydig cell tumors (Stewart et al, 1997), proving that inhibin is a sensitive immunohistochemical marker of a wide range of gonadal stromal tumors. Strong cytoplasmic staining of 17/19 cases of hepatocellular carcinoma, including pleomorphic and glandular variants, has been demonstrated (McCluggage et al, 1997). In this study focal weak luminal staining of glands of adenocarcinoma was also present. Hence, immunostaining with antiinhibin antibody may be of value in the differentiation of hepatocellular carcinoma from adenocarcinoma involving the liver.
Comments
Inhibin antibody is useful in confirming the diagnosis of both adult and juvenile granulosa cell tumors, especially tumors with unusual growth patterns and in metastatic sites. It is also helpful in distinguishing hepatocellular carcinoma from adenocarcinomas in the liver.
References
•Findlay JK 1993. An update on the roles of inhibin, activin and follistatin as local regulators of folliculogenesis. Biology of Reproduction 48:15-23.
•Fleming P, Wellman A, Hansjâg Maschek, Lang H, Georgii A 1995. Monoclonal antibodies against inhibin represent key markers of adult granulosa cell tumors of the ovary even in their metastases. A report of three cases with late metastasis, being previously misinterpreted as haemangiopericytoma. American Journal of Surgical Pathogy 19: 927-933.
•Groome N, Lawrence M. 1991 Preparation of monoclonal antibodies to the beta A subunit of ovarian inhibin using a synthetic peptide immunogen. Hybridoma 10:309-316.
•Groome N, Hancock J, Betteridge A, Lawrence M, Craven R 1990. Monoclonal and polyclonal antibodies reactive with the 1-32 amino terminal sequence of the alpha subunit of human 32K inhibin. Hybridoma 9:31-42.
•Lappn RE, Burger HG, Bouma J, Bangah M, Krans M, De Brujn HWA 1989. Inhibin as a marker for granulosa-cell tumors. New England Journal of Medicine 321: 790-793.
•McCluggage WG, Maxwell P, Patterson A, Sloan JM 1997. Immunohistochemical staining of hepatocellular carcinoma with monoclonal antibody against inhibin. Histopathology 30: 518-522.
•McLachlan RI, Robertson DM, Burger HG, De Kretser DM 1987. Circulating immunoreactive inhibin levels during the normal menstrual cycle. Journal of Clinical Endocrinology and Metabolism 65:954-961.
•Stewart CJR, Deffers MD, Kennedy A 1997. Diagnostic value of inhibin immunoreactivity in ovarian gonadal stromal tumors and their histological mimics. Histopathology 31:67-74.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
