Absolutely! Besides HIV infection which should be excluded in all patients with recurrent bouts of bacterial pneumonia irrespective of age, “selective polysaccharide antibody deficiency” which may account for 8% of adults with recurrent CAP, should also be excluded (1). These patients (median age 48 years) often present with recurrent bouts of bacterial pneumonia despite having normal serum total immunoglobulin (IgG, IgA, and IgM) levels (1,2). They have a normal response to tetanus toxoid (a protein) but cannot mount adequate antibody response against polysaccharide antigens of pathogens such as pneumococcus. IVIG may reduce the risk of future bouts of pneumonia in this condition (2).
1. Cohn JA, Skorpinski E, Cohn JR. Prevention of pneumococcal infection in a patient with normal immunoglobulin levels but impaired polysaccharide antibody production. Ann Allergy Asthma Immunol 2006;97:603-5.
2. Cheng YK, Kecker PA, O’Byrne MM, Weiler CR. Clinical and laboratory characteristics of 75 patients with specific polysaccharide antibody deficiency syndrome. Ann Alergy Asthma Immunol 2006;97:306-311.