Primary selective IgM deficiency: an ignored immunodeficiency.

Area of Science:

• Immunology
• Primary Immunodeficiencies

Background:

• Selective Immunoglobulin M (IgM) deficiency is an underrecognized primary immunodeficiency.
• It affects both children and adults, presenting with infections, allergies, and autoimmune diseases.

Purpose of the Study:

• To highlight the clinical significance and diverse manifestations of selective IgM deficiency.
• To discuss potential pathogenetic mechanisms and therapeutic approaches.

Main Methods:

• Review of existing literature and case reports on selective IgM deficiency.
• Analysis of clinical presentations, associated conditions, and immunological findings.

Main Results:

• Selective IgM deficiency is linked to increased susceptibility to bacterial, viral, and fungal infections.
• Associated conditions include allergic diatheses, autoimmune diseases, and 22q11.2 deletion syndrome.
• Impaired specific IgG antibody responses to pneumococcal polysaccharides are noted in some patients.

Conclusions:

• Selective IgM deficiency is more prevalent than previously thought and requires greater clinical attention.
• Pathogenesis may involve T helper cell activity, suppressor T cell activity, or intrinsic B cell defects.
• Immunoglobulin therapy shows promise for patients with impaired antibody responses.