Which of the following does not protect body surfaces

Pattern recognition receptors (PRR) include:

Neutrophil defensins are

The initial complement component that is bound by complement-fixing antibodies is:

HLA-DR2 is a risk factor for:

Which of the following immune cells/molecules are most effective at destroying intracellular pathogens?

A living microbe with reduced virulence that is used for vaccination is considered:

In agglutination reactions, the antigen is a………
in precipitation reactions, the antigen is a……………

Which of the following convey the longest lasting immunity to an infectious agent?

B cells that produce and release large amounts of antibody are called:

Which of the following is used for typing when a patient is being prepared for an organ transplant?

a patient on antidepressant drugs develops hemolytic anemia which resolves shortly after the drug is withdraw . what is the mechanism involved in this situation ?

a one year old boy had several bouts of pneumonia . he is now evaluated for potential immunologic deficiency .depressed serum level of which complement component may predispose to this condition ?

a 34 year old man presents with fever , cough and night sweats .TB was suspected and after injection of PPD , skin reaction showed erythema and induration at the site of injection within 2 days .which type is 1ry responsible for this reaction?