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:
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
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
fights against infection
Neutrophils are packed with hydrolytic enzymes that degrade the ECM to allow quick passage. This can lead to bronchiectasis.
Normal CD4 levels are 1.7-2.8 x 109/L .
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.