Volume 194 - Issue 4
Chronic suppurative lung disease and bronchiectasis in children and adults in Australia and New Zealand
Authors: David S Gillis and D Sean Riminton
Med J Aust 2011; 194 (4): 213. || doi: 10.5694/j.1326-5377.2011.tb03789.x
Published online: 21 February 2011
Published online: 21 February 2011
To the Editor: We view with concern the listed minimum investigations for chronic suppurative lung disease and bronchiectasis in children and adults recommended in the position statement from the Thoracic Society of Australia and New Zealand and the Australian Lung Foundation, published in the Journal.1 We do not agree with the inclusion of measurement of IgG subclasses in the list.
Interpretation of IgG subclasses is fraught with difficulties.2 It is unclear whether the isolated finding of low levels of one or more IgG subclasses is a risk factor for developing severe recurrent bacterial infections. Individuals with complete absence of IgG subclasses due to gene deletions may remain entirely asymptomatic, and the finding of a low or absent response to specific bacterial protein and/or polysaccharide is more closely associated with propensity to infection. In addition, the lack of reproducibility of IgG subclass assays and lack of well standardised age-specific reference ranges hinder interpretation of results.
Of major concern is the lack of evidence to provide clear guidance on the efficacy of immunoglobulin replacement therapy in IgG subclass deficiency. In general, the finding of isolated IgG subclass deficiency is not sufficient grounds for commencement of immunoglobulin therapy and is not recommended as an indication for intravenous immunoglobulin therapy in the current Australian guidelines.2
We urge the authors to reconsider the inclusion of IgG subclasses in the list of minimum investigations for chronic suppurative lung disease and bronchiectasis.
References
- Chang AB, Bell SC, Byrnes CA, et al. Chronic suppurative lung disease and bronchiectasis in children and adults in Australia and New Zealand. A position statement from the Thoracic Society of Australia and New Zealand and the Australian Lung Foundation. Med J Aust 2010; 193: 356-365. <eMJA full text>
- Asia Pacific Immunoglobulins in Immunology Expert Group. Consensus recommendations for the use of immunoglobulin replacement therapy in immune deficiency. 2nd ed. Melbourne: APIIEG, 2009: 30-31. 0_i1095832