At what levels are CPK levels actually considered pathological?

British and Canadian researchers have sought to establish non-pathogenicity reference ranges for creatine phosphokinase (CPKEnzyme contenue dans les cellules musculaires, qui est libérée dans le sang en cas d’atteinte musculaire.) levels measured in routine clinical practice:

• the clinical and laboratory records of all individuals referred to a neuromuscular referral centre between 2018 and 2022 were retrospectively analysed,
• of the 488 records, 276 related to inflammatory myopathies, 89 to a non-inflammatory myopathy and 123 to another aetiology not necessarily neuromuscular,
• the sensitivity, specificity and predictive value figures obtained by the laboratory were compared with those set out by the European Federation of Neurological Societies,

According to the authors, a CPK threshold of 1,000 IU/l would constitute an acceptable and valid figure for strongly suspecting a primary muscle disorder, whether inflammatory or non-inflammatory.