Positve antibodies to Pseudomonas aeruginosa

Question

My son, 14 years old, was diagnosed in August of being positive for antibodies (against Pseudomonas aeruginosa). Sputum has been always negative so far. He was treated with Ciprofloxacin and Colistine. When should we check the antibodies again? I am not sure what to do as I have received very different answers from the CF clinic. Does it make sense to control sputum resp. swabs monthly now? I am looking forward for your answer.

Answer

Hi,

thank you for your request. If I understand you correctly, sputum was negative but Pseudomonas aeruginosa antibodies were positive. Next is a control for Pseudomonas aeruginosa antibodies, to provide evidence of a successful eradiction resp. to show that the antimicrobial treatment led to clearance of P.aeruginosa bacteria from the lungs of your son. (App. 3 weeks after a successful antimicrobial treatment the antibody values should be half of the initial value).
If you follow the British guidelines, eradication is successful, if 3 tests for P.aeruginosa are negative for 6 months. In this regard it seems reasonable to check the antibodies at least every 8 weeks (but not more often than every 4 weeks): Now (resp. 4 weeks after finishing the antimicrobial therapy) once the antibodies. In case they are negative repeat them every 4-8 weeks. Repeat at least after 2 and 4 months. If the antibodies are negative after a 6 month interval, the eradication was successful.
The antibodies were positive in August, did they also check for P.aeruginosa in the nose by swabs? In case the antibodies are still positive, this should be checked. There is the possibility that you can only isolate them from nasal washings, if it is not possible from nasal swabs.

I hope this was helpful for you.

Kind regards,

Sabina Schmitt-Grohé

20.01.2017

20.01.17
There is little data on Pseudomonas antibodies and their meaning in the control of a successful eradication.
There is the German guideline by Mueller et al: "S3 guidelines lung disease in CF - module 1 "diagnostics anbd therapy after the first finding of Pseudomonas aeruginosa"; there it is written about the antibodies:
"Statement 5b: for PA negative patients before the first finding of PA, it is recommended to measure the PA-antibodies yearly. After successful eradication, control of the PA antibodies should be done after 3 months and than again yearly. Grade of recommendation: B ".
In the above case it is even more difficult, as there is no microbiological finding of PA, so that a successful eradication cannot be monitored by the microbiology findings. Therefore the antibodies could play a more important role, however there is no exact data on it how the antibodies behave after eradication and there are centers, that experienced, that the antibodies might stay high for a longer period of time even after successful eradication.
D. d'Alquen