Modelling long-term evolution of chitotriosidase in non-neuronopathic Gaucher disease.
Chitotriosidase, an enzyme secreted by activated macrophages, is widely used as a biomarker for therapeutic monitoring and patient follow-up in Gaucher disease (GD), a lysosomal disorder caused by an inherited deficiency of glucocerebrosidase. We analyzed the long-term evolution of chitotriosidase aiming to establish an accurate model that describes the influence of enzyme replacement therapy (ERT) and the impact of several covariates. A total of 55 patients with non-neuronopathic (type 1) GD were followed for almost 17 years (during a maximum of 7.57 and 8.96 years, before and after the onset of ERT, respectively). Plasma chitotriosidase activity, measured yearly before the onset of ERT and at 6-month intervals after the initiation of ERT, was analyzed as a function of several covariates (age at diagnosis and at ERT initiation, nature of the most frequent genotypes, spleen status and the occurrence of bone complications). The evolution of chitotriosidase was approximated by a sigmoidal function, which allows the calculation of predicted values, based on several parameters inferred from our data. Splenectomy and the occurrence of bone complications significantly delayed the decline in chitotriosidase activity and induced higher mean residual values after long-term (4-9 years) ERT. Likewise, patients who started ERT infusions under 15 years of age had significantly higher mean residual chitotriosidase activities. The influence of other covariates did not reach statistical significance. In conclusion, we propose a novel model describing the evolution of chitotriosidase, allowing more accurate treatment adjustments, according to the variations of this biomarker.
a Department of Medical Biochemistry , "Iuliu Haţieganu" University of Medicine and Pharmacy , Cluj-Napoca , Romania.
Cristina
C
Drugan
b Department of Medical Informatics and Biostatistics , "Iuliu Haţieganu" University of Medicine and Pharmacy , Cluj-Napoca , Romania.
Tudor C
TC
Drugan
c Department of Paediatrics, Paediatric Clinic I , "Iuliu Haţieganu" University of Medicine and Pharmacy , Cluj-Napoca , Romania.
Paula
P
Grigorescu-Sido
c Department of Paediatrics, Paediatric Clinic I , "Iuliu Haţieganu" University of Medicine and Pharmacy , Cluj-Napoca , Romania.
Ioana
I
Naşcu
D000293:Adolescent; D000328:Adult; D005075:Biological Evolution; D015415:Biomarkers / Q000097:blood*; D002648:Child; D005260:Female; D005776:Gaucher Disease / Q000201:enzymology*; D006596:Hexosaminidases / Q000097:blood* / Q000235:genetics; D006801:Humans; D008297:Male; D055815:Young Adult
D015415:Biomarkers; D006596:Hexosaminidases; C086400:chitotriosidase
Biomarkers; enzyme replacement therapy; lysosomal storage diseases; regression analysis; splenectomy