Abstract
Background: Immunofluorescence (IF) labelling of ciliary proteins shows if they are present and where they are localised in patients with PCD. It is increasingly used as a diagnostic tool but data regarding use for diagnostics is limited.
Aim: To describe our experience introducing IF labelling of ciliary proteins to aid PCD diagnosis in our service.
Methods: We performed IF on samples from 35 patients with a clinical history fitting PCD and abnormal or equivocal ciliary function. Cells from nasal brushings were air dried onto slides, and incubated with antibodies to DNAH5, DNALI1 and RSPH4A. We compared IF results to 'gold standard' analysis of axonemal structure by TEM.
Results: IF was easy to adopt, used equipment likely to be available in diagnostic histology labs and provided results within 48 hours, substantially faster than TEM.
IF proved to be 57% sensitive and 100% specific compared to 'gold standard' TEM analysis. Four PCD patients were correctly identified by IF, 2 with absence of DNAH5 labelling and outer dynein arm deficiency (OAD) by TEM, one with absence of DNAH5 and DNALI1 labelling and outer and inner arm deficiency (O&IAD) by TEM, and one with absence of RSPH4A and microtubule (MT) disarrangement by TEM. Sensitivity was reduced due to 3 false negative results; 2 had DNAH5 and DNALI1 labelling despite O&IAD, 1 had labelling of all 3 antibodies and MT disarrangement by TEM.
Conclusions: IF easily and rapidly identified the presence of ciliary proteins. Using these antibodies alone 3/7 PCD cases identified by TEM would be missed. This was despite appropriate controls and may reflect our inexperience of IF. IF can provide an excellent aid to diagnostics but requires training before adoption.
- Copyright ©the authors 2016
