On the other hand, molecular analysis is not required for the diagnosis of CVID but might be an option if there are other affected family members. The patient’s response to vaccines based on protein (IgG antibodies to tetanus and diphtheria) and polysaccharide (IgG antibodies to serotypes of the polysaccharides in the pneumococcal vaccine) requires assessment unless the antibody levels are deficient.įlow cytometry can be used to determine levels of circulating memory B cells, and levels of isotype switched memory B cells (as mentioned before). Also, IgM and/or IgA should be below the normal limits.

Serum IgG should be below the normal limits and normally under 400mg/dL. Generally, there are no uncommon findings in routine laboratories. Magnetic resonance, cerebrospinal fluid analysis in case of neurological symptoms, especially infectious ones (on-demand). Different modes of inheritance, such as autosomal dominant with variable penetrance, autosomal recessive, and X-linked forms, have been reported. There is no observable, clear pattern of inheritance.

Other monogenic defects reported include MSH5, CD81, and CD20 deficiencies however, CVID can be present without a known genetic defect. It is known that environmental and genetic factors may be involved: approximately, 20% of CVID patients have a first-degree family member with a selective IgA deficiency while the specific environmental factors are unclear, the genetic influence in CVID is believed to cause an intrinsic B cell defect (CD19-deficiency by mutations in CD19 16p11.2), an intrinsic T cell defect (ICOS-deficiency by mutations in ICOS 2q33), and mutations in TNF receptors (TACI-deficiency or BAFFR- deficiency by mutations in TNFRSF13B and TNFRSF13C respectively 17p11.2 and 22q13.1-q13.31). The main cause of CVID remains unknown despite more than four decades of investigation.

What is the pathology of SCID