Which of the following statement about 'interferon' is not true:
|A||It is a glycoprotein|
|B||Produced by vertebrate host cells as a defence mechanism|
|C||Produced only in response to viral infection|
|D||Acts by preventing translation of viral RNA|
|E||It is species specific|
a. Interferons are glycoproteins. There are three types of interferons; alpha, beta and gamma. Alpha, beta and gamma interferons are produced by leukocytes, fibroblasts and T lymphocytes respectively.
b. Alpha and beta interferons have antiviral activity. These are produced with in hours of viral infection and act on surrounding uninfected cells.
c. Within these cells, they cause the synthesis of certain proteins, which inhibit translation of viral mRNA. Interferons are not virus specific, however they are species specific.
Classification of primary immunodeficiency syndrome.
A. Disorders of specific immunity
I. Humoral immunodeficiencies (B cell defects)
a. X *-linked agammaglobulinemia b. Cell Defer
b. Transient hypogammaglobulinemia of infancy
c. common variable immunodeficiency (Late onset hypogammaglobulinemia)
d. Selective immunoglobulin deficiency (IgA, IgM or IgG subclasses)
e. Immunodeficiencies with hyper-IgM
f. Transcobalamin II deficiency
II. Cellular immunodeficiencies ( T cell defects)
a. Thymic hypoplasia (Digeorge’s syndrome)
b. Chronic mucocutaneous candidiasis
c. Purine nucleoside phosphorylase (PNP) deficiency.
III. Combined immunodeficiencies (B and T cell defects)
a. Cellular immunodeficiency with abnormal immunoglobulin synthesis (Nezelof syndrome)
b. Ataxia telangiectasia
c. Wiskott-aldrich syndrome
d. Immunodeficiency with thymoma
e. Immunodeficiency with short – limbed dwarfism
f. Episodic lymphopenia with lymphocytotoxin
g. Severe combined immunodeficiencies
i. ‘Swiss type’ agammaglobulinemia
ii. Reticular dysgenesis of de Vaal
iii. Adenosine deaminase (ADA) deficiency
* B= Bruton’s B = B cell defect B= Boys B = Bacterial infection.
B. Disorder of complement
a. Complement component deficiencies
b. Complement inhibitor deficiencies
C. Disorder of phagocytosis
b. granulomatous disease
c. Myeloperaoxidase deficiency
d. Chediak-Higashi syndrome
e. Leucocyte G6PD deficiency
f. Job’s syndrome
g. Tuftsin deficiency
h. Lazy leucocyte syndrome
i. Hyper-IgE syndrome
j. Actin binding protein deficiency
k. Shwachman’s disease