From the Guidelines
For patients with low secretory IgA, I recommend monitoring over time for the occurrence of complications, as most affected patients are asymptomatic, but some do have problems over time, including respiratory and gastrointestinal tract infections, atopy, autoimmune diseases, celiac disease, and malignancy 1.
Key Considerations
- Patients with serum IgA levels of less than 7 mg/dL and normal serum IgG and IgM levels should be given a diagnosis of Selective IgA Deficiency (SIGAD) 1.
- The general principles of management are focused on preventing and treating infections, as well as monitoring for autoimmune diseases and other complications.
- Rare patients with SIGAD might benefit from IVIG replacement therapy, particularly those with recurrent infections that negatively affect quality of life and in whom aggressive antibiotic therapy and prophylaxis fail or who have intolerable side effects or hypersensitivity to antibiotics 1.
Management Approach
- Monitor patients with SIGAD over time for the occurrence of complications, as clinical manifestations can include respiratory and gastrointestinal tract infections, atopy, autoimmune diseases, celiac disease, and malignancy 1.
- Consider IVIG replacement therapy in rare cases, taking into account the potential benefits and risks, including the presence of anti-IgA antibodies 1.
- Emphasize the importance of preventive measures, such as vaccinations and aggressive treatment of infections, to reduce the risk of complications.
- Focus on supporting the patient's overall health and well-being, rather than solely on treating the low secretory IgA levels, to improve quality of life and reduce morbidity and mortality.
From the Research
Low Secretory IgA Treatment
- Low Secretory IgA is associated with increased susceptibility to infections, particularly those caused by Streptococcus pneumoniae and Haemophilus influenzae 2, 3.
- Treatment options for low Secretory IgA are limited, but immunoglobulin replacement therapy may be beneficial in some cases 4.
- Azithromycin has been shown to be effective in treating community-acquired pneumonia, including cases caused by macrolide-resistant S. pneumoniae 5.
- Secretory-IgA antibodies play a crucial role in immunity to S. pneumoniae, and inducing these antibodies through vaccination may be an effective way to prevent colonization and infection 6.
- The importance of Secretory IgA in maintaining intestinal homeostasis and preventing disease manifestations is highlighted, and its role in immune exclusion of pathogenic microorganisms is emphasized 2.
Treatment Considerations
- Patients with low Secretory IgA may benefit from regular administration of human gamma globulin (IgG) preparations, which can provide protective antibodies against S. pneumoniae serotypes 4.
- Monitoring of S. pneumoniae infections in patients treated with IgG and tracing information about IgG lots used to treat these patients is recommended 4.
- The effectiveness of antibodies in vivo may not be fully captured by in vitro testing, and caution should be used when interpreting currently available assays that measure pneumococcal antibody levels 4.