Upload
laureen-holmes
View
229
Download
1
Tags:
Embed Size (px)
Citation preview
IN THE NAME OF GOD,
THE COMPANIONATE THE MERCIFUL
Mahmoud Najafi
Gonadal SteroidsAnd Their Effect On
Immune Function
Gonadal Steroids
AndrogensEstrogensProgesterone
Woman have:
A more vigorous immune responseA more developed thymusHigher immunoglobulin concentrationStrong primary and secondary responsesMore resistance to the induction of
toleranceGreater ability to reject tumor and allograft
A higher female/male susceptibility ratio:
Systemic Lupus Erytematosus(10:1)Rheumatoid Arthritis(4:1)Multiple SclerosisMyasthenia GravisAutoimmune thyroid disease
Gonadal steroids and SLE
Decreased androgen/estrogen ratio (aggravated)– An increase aromatase activity– Pregnancy– Administration of estrogens containing
contraceptives
Increased androgen/estrogen ratio (ameliorated)– A therapeutic effect
Is aggravated by estrogens
Gonadal steroids and RA
Oral contraceptive and Pregnancy– Mitigate the development of the disease
The age of onset of RA in woman is 40-50 (Menopause)
Is ameliorated by estrogens
Animal Models
Female animal– More rapidly reject allograft transplanted– More vigorous immune response
• Humoral immunity• Cell mediated immunity
Female Rats
Administration of testosterone – Largely prevents the onset of autoimmune
disease– Castrated male demonstrate disease
acceleration
Thymectomy – Ablates beneficial effect of testosterone
Androgen and Estrogen binding site
ThymusBone MarrowPeripheral immune system Gonadectomy
– Hyperplasia of the thymus
The administration of exogenous androgen and estrogen– Thymic involution
Progenitor T & B lymphocytes
Sex steroids have receptor– Positive effect on T-cell lymphopoiesis– Negative effect on B-cell lymphopoiesis
• Ovarietomy Increase number of B-cell
T & B lymphopoiesis is suppressed during pregnancy
Influencing the function of mature T and B cells
Estrogen- Increase activity of CD4+ T cells- Decrease activity of CD8+ T cells- enhances IFN-γ (In vitro study)- Treatment by estrogen
• Increase the number of autoreactive immunoglobulin
Androgen- Have receptor on peripheral T and B cells
GnRH
Synthesis within the hypothalamusGnRH RNA has been detected in spleen & thymus T-cell has GnRH receptor
– May be involved in the maturation and senescence cells within the immune system
Pregnancy
Measure of cell-mediated immunity are suppressed
Humoral immunity is preserved or enhancedLevel of variety of cytokine declineElevated level of Glucorticoids
– Potent inhibitory of IFN-γ• Is a powerful abortifacient
Hypersensitivity and Pregnancy
Systemic Lupus Erytematosus – Type III Hypersensitivity – aggravated during the pregnancy
Rheumatoid Arthritis – Type IV Hypersensitivity – suppressed during the pregnancy
Hypersensitivity and Pregnancy
MS− Progesterone- Attenuate disease severity
• Reduce the inflammatory
response • Reduce demyelination in
the spinal cord
Bone metabolism
Estrogens & androgens– Bone protective effect– Decreased of inflammatory cytokines
• TNF• IL-1, IL-6
Bone loss in post-menopausal– Estrogen replacement therapy
Androgens
Anti-inflammatory- Receptors present on immune tissues- Immunosuppressive on both T & B cells- Decrease thymic mass- Suppress antibody response- Increase TGF-β
Estrogens
Pro or Anti-inflammatory (dependent on the disease)- Receptors present on immune tissues- Decrease thymic mass- Inhibit suppressive T-cells- Facilitate T-helper lymphocyte maturation- Stimulate B-cell mediated antibody response
Progesterone
Anti-inflammatory- Receptors present on some immune tissues