A prognostic index as diagnostic strategy in children suspected of mitochondriocytopathy
M E Rubio-Gozalbo1, R C Sengers, J M Trijbels
1Department of Metabolic Diseases, University Hospital Nijmegen, The Netherlands. E.Rubio@ckskg.azn.nl
Insights
This study developed a prognostic index to optimize screening for pediatric mitochondriocytopathy, reducing unnecessary muscle biopsies. The index uses five key parameters to predict the likelihood of a normal biopsy result.
Area of Science:
- Biochemistry
- Pediatric Neurology
- Genetics
Background:
- Mitochondriocytopathy diagnosis in children often requires invasive muscle biopsy.
- Accurate pre-biopsy screening is crucial to avoid unnecessary procedures and associated risks.
Purpose of the Study:
- To develop and validate an optimal screening tool for pediatric patients suspected of mitochondriocytopathy.
- To determine if a muscle biopsy is justified based on specific clinical and biochemical parameters.
Main Methods:
- A cohort of 45 pediatric patients with suspected mitochondriocytopathy was studied.
- Comprehensive investigations included medical history, physical exams, cardiac/ophthalmologic evaluations, biochemical tests, neuroimaging, and muscle biopsy.
- Statistical analysis identified parameters correlated with muscle biopsy results to construct a prognostic index.
Main Results:
- Five parameters were selected: age <4 years, elevated fasting lactate to pyruvate ratio, elevated thrombocyte count, elevated lactate, and elevated alanine.
- A prognostic index was created, assigning a score based on the presence or absence of these parameters.
- The index demonstrated a clear correlation between the score and the probability of a normal muscle biopsy, with higher scores indicating a lower probability of normality.
Conclusions:
- The developed prognostic index is a valuable tool for clinicians.
- It aids in deciding whether the suspicion of mitochondriocytopathy warrants a muscle biopsy in pediatric patients.
- This screening approach can help optimize diagnostic pathways and resource allocation.
Abstract:
The aim of this study was to assess an optimal screening for paediatric patients suspected of mitochondriocytopathy to justify a muscle biopsy. Forty-five patients were included. Medical history, physical examination, cardiac and ophthalmologic evaluation, clinical chemical investigations, in vivo function tests, neuroimaging and a skeletal muscle biopsy were performed in all patients. The results of the biochemical muscle studies were compared with the results of the other investigations. First, parameters with a statistical relationship with the result in muscle, normal or deficient, were selected. Secondly, a prognostic index was constructed using these parameters. Five parameters were selected: age <4 years, elevated fasting lactate to pyruvate ratio, elevated thrombocyte count, elevated lactate, and elevated alanine. Each parameter was scored 0 (not present) or 1 (present). The chance of a normal biopsy with a given value of this index (sum of the scores) was calculated: logit (Pr) = alpha + beta x index; alpha: -0.8167 and beta: 0.8331. (Pr: probability of normal biopsy.) The chance of a normal biopsy with an index value of 5 is 0.03, 4 is 0.07, 3 is 0.16, 2 is 0.30, 1 is 0.50 and 0 is 0.69. This prognostic index is a valuable instrument in deciding whether the suspicion of mitochondriocytopathy is strong enough to merit a muscle biopsy.
