Zusammenfassung
Hintergrund: Umfragen in den USA und in Großbritannien haben Diskrepanzen zwischen der praktischen
Durchführung des Schweißtests und Leitlinien des „National Committee for Clinical
Laboratory Standards” (NCCLS) aufgezeigt, die das Risiko falsch positiver und negativer
Ergebnisse erhöhen. Um die Qualität des Schweißtests in deutschen Ambulanzen für zystische
Fibrose (CF) zu erfassen, wurde eine Umfrage durchgeführt.
Methoden: Ein Fragebogen wurde an alle 123 am Projekt „Qualitätssicherung Mukoviszidose” teilnehmenden
Ambulanzen in Deutschland versandt und die Ergebnisse mit den NCCLS-Leitli-nien verglichen.
Ergebnisse: 88 der 113 antwortenden Ambulanzen führen zwischen 30 und 1100 (Median 200) Schweißtests
pro Jahr mittels Pilocarpin-Iontophorese durch. Die empfohlene Schweißsammelzeit von
20-30 Minuten (NCCLS-Leitlinie: 30 min) wird von 33% der Zentren eingehalten. Die
minimale akzeptierte Schweißsekretionsrate (NCCLS-Leitlinie: ≥1000 mg/m2/min) beträgt 100-7500 (Median 1000) mg/m2/min. In 3% der Zentren wird die Osmolalität, in 24% Natrium und in 53% die Leitfähigkeit
gemessen. Chlorid - nach den NCCLS-Leitlinien der einzige diagnostische Parameter
- wird nur von 58% aller Ambulanzen angewandt. Der empfohlene Referenzbereich für
CF-Patienten >60 mmol/l wird in 78% der Chlorid messenden Zentren angewandt.
Schlussfolgerungen: Es bestehen erhebliche Diskrepanzen zwischen der Durchführung des Schweißtests in
deutschen CF-Ambu-lanzen und den NCCLS-Leitlinien hinsichtlich Schweißsammlung, Analyse
und Referenzwer-ten. Chlorid, der einzige diagnostisch anerkannte Parameter, wird
nur in 58% aller deutschen CF-Ambulanzen gemessen.
Abstract
Background: Surveys in USA and UK have shown inconsistencies between practice of sweat testing
and guidelines of the National Committee for Clinical Laboratory Standards (NCCLS),
which could increase the risk of false-positive and -negative results. To determine
the current practice of sweat testing in German cystic fibrosis (CF)-centres a survey
was performed.
Method: A questionnaire was mailed to all 123 German CF-centres that join the German CF-register.
The results were compared with the NCCLS-guidelines.
Results: 88 out of 113 responding centres perform 30-1100 (median 200) sweat tests by pilocarpine
iontophoresis per year. The recommended sweat sample time of 20-30 min was accepted
by 33% of all centres. Minimum acceptable sweat rates were quoted between 100 and
7500 (median 1000) mg/m2/min differing from the recommended 1000 mg/m2/min. Osmolality was measured in 3%, sodium in 24% and conductivity in 53% of the
centres. Chloride, the only accepted diagnostic measurement by the NCCLS, was investigated
by only 58% of all centres. The recommended chloride CF-reference value of >60 mmol/l
was used in 78% of centres that perform chloride testing.
Conclusions: Major areas of inconsistencies between sweat testing practice in German CF-centres
and NCCLS-guidelines are sweat collection, analyzing method and reference values.
Chloride, the only accepted diagnostic measurement by the NCCLS, was investigated
only by 58% of all centres.
Schlüsselwörter
Chlorid - zystische Fibrose - Diagnose - Schweißtest
Key words
chloride - cystic fibrosis - diagnosis - sweat
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Korrespondenzadresse
L. Naehrlich
Kinder- und Jugendklinik der Universität Erlangen-Nürnberg
Loschgestraße 15
91054 Erlangen
Phone: +49/913/185 33 11 8
Fax: +49/913/186 53 31 13
Email: lutz.naehrlich@kinder.imed.uni-erlangen.de
