Assay

Pneumococcal antibodies (specific)

Key Words

Pneumococcal specific Ab's (Functional Ab's), APA

Specimen Collection

Serum (brown)

Turnaround time

15 days

This test is referred to another centre:                                                                                                                             Department of Clinical Chemistry and Immunology                                                                                                                   Level 4
Addenbrookes Hospital NHS Trust
Hills Road
Cambridge CB2 2QQ
Tel: 01223 217215
Fax: 01223 217794

Test indications

This test is used in the diagnosis of Primary Immune deficiency where 13 pnuemococcal specific serotypes are measured. This test should be requested for patients who have a clinical history of recurrent infections and/or evidence of bronchiectasis.  11/13 serotypes tested are contained in the childhood conjugated pneumococcal vaccine Prevenar13 (introduced in 2010).  Protective levels of these show satisfactory response to the T cell dependent antibody production pathway. All 13 serotypes are contained in the unconjugated vaccine Pneumovax.  Protective response confers correct function of the T-independent antibody production pathway. Patients should have this test done in the following clinical circumstances:

a) Patients, especially children, with recurrent bacterial sepsis; particularly of the upper and lower respiratory tract.

b) Patients with invasive disease caused by encapsulated organisms.

c) Patients with selective antibody deficiency states and in monitoring immunoglobulin replacement therapy in such patients.

d) Immunological reconstitution following bone marrow transplant.

e) Patients having haemoglobinopathies or who are due to undergo or who have had a splenectomy should have their levels of antibodies to encapsulated bacteria (i.e. pneumoccocal & Hib) monitored.                        

f) Patients with radiographical evidence of bronchiectasis.

<!--[if !supportEmptyParas]-->Knowledge of vaccine history is imperative for correct interpretation.  Specific clinical symptoms are also advantageous. If a poor response if found, patients will be required to be vaccinated and retested 4 week post vaccination.  Specific interpretation is given for each patient result.  Children under the age of 2 years do not normally mount an immune response to either Pneumovax or to natural exposure. In contrast, the conjugate pneumococcal vaccine (Prevenar), is fully immunogenic from birth.

Methodology

Flowcytometric bead array (Luminex)

Interferences

Contact referral centre

Reference Range

Putative protective levels 0.35 µg/mL

Analytical error

Contact referral centre

Reference change value

N/A