Immunologic Conditions and Disorders








  • autoimmune conditions
  • immunodeficiencies
  • immunosuppression


Serious primary immune deficiency diseases are not rare as a group, and there are over 140 known genetic causes.

An approach to recurrent infections is important.


Causes of immunodeficiency include:

  • hypogammaglobulinemia
  • B cell deficiency
  • IgA deficiency
  • CD-4 deficiency
  • common variable immunodefiency

IgA deficiency


chronic infections at mucosal surfaces

clinical variability: may be based on function of IgM at mucosal surface

most people do not require treatment beyond antibiotics

no known cause


common variable immunodeficiency

can develop at any age; perhaps genetics

apparent defect in T cell/B cell communication

normal number of B cells, but no antibody response

also problems with viral clearance and occasionally autoimmunity


Immune system deregulation

fights against infection

tumour surveillance

autoimmune disease


Neutrophils are packed with hydrolytic enzymes that degrade the ECM to allow quick passage. This can lead to bronchiectasis.


B Cell Deficiency


CD4 Deficiency

Normal CD4 levels are 1.7-2.8 x 109/L .

With T cell deficiency, one sees viral, parasitic, and fungal infections that become serious.

T cells also respond to intracellular bacterial infections, and T cell deficiencies can lead to increased susceptibility to bacteria including salmonella and mycobacteria.

There is also an effect on the humoral response, leading to increased susceptibility to bacterial infections.