Comparison of the results of immunoglobulin (IgA,IgG,IgM), IgG subclasses and specific antibodies of patients with frequent sinopulmonary problems.

Elo Saue1,*

1Diagnostic Clinic Central Laboratory, East-Tallinn Central Hospital, Tallinn, Estonia

Introduction: The most common indication of antibody deficiency and other immunodeficient disorders is an increased susceptibility to infections.The potential warning signs of primary immunodeficiency are recurrent, unusual infections which need frequent courses of antibacterial treatment. Pyogenic sinopulmonary infections often caused by encapsulated bacteria (S.pneumoniaePCP and H.influenzaeB) are common in antibody deficient patients.

Objectives: The aim was to estimate the immunoglobulins, the IgG subclasses and the values of specific antibodies for the detection of primary immunodeficiency.

Methods: Immunoglobulins (IgA,IgG,IgM) were measured using the turbidimetry  assay (Cobas 6000, Roche Diagnostics). IgG subclasses were measured using the nephelometry assay (Minineph™ Plus, BindingSite). S.pneumoniaePCP  IgG and H.influenzaeB  IgG were measured using the Elisa assay (VaccZyme™, BindingSite).

Results: Within 4 months in 2013, we measured the immunoglobulin levels in 59 patients with frequent sinopulmonary problems treated by clinical immunologists.

62% (10/16) of patients aged 0-5 years showed a decrease in specific antibody values (S.pneumoniaePCP  IgG and/or H.influenzaeB IgG), normal immunoglobulin values and values of IgG subclasses.

66% (8/12) of patients aged  5-18 years showed a decrease in specific antibody values, normal immunoglobulin values and values of IgG subclasses. Two patients had selective IgA deficiency.

70% (19/27) of patients aged 18 and over, showed normal immunoglobulin values but decreased levels of IgG subclasses and/or specific antibody values. 1 patient had selective IgA deficiency and 1 patient had agammaglobulinaemia.

Conclusion: Early suspicion of primary immunodeficiency is important, especially in the presence of recurrent sinopulmonary infections. We recommend using IgG subclasses and specific antibodies (S.pneumoniaePCP IgG and/or H.influenzaeB IgG) for diagnostic purposes.

Keywords: Biochemistry, Inflammation