Plasma chitotriosidase activity versus CCL18 level for assessing type I Gaucher disease severity: protocol for a systematic review with meta-analysis of individual participant data

Table 2 Pre-specified surrogate outcomes reflecting Gaucher disease activity

Outcomes	Definition^a
Primary outcome	The primary outcome is a composite of one or more individual components among the following:
	- Liver volume >1.25 MN
	- Spleen volume >5 MN
	- Hemoglobin concentration <11.0 g/dL (<10.0 g/dL for patients 6 to 59 months of age)
	- Platelet count <100 × 10⁹/mL
Secondary outcomes	1. Composite of one or more individual components among the following:
	- Liver volume >2.5 MN
	- Spleen volume >15 MN
	- Hemoglobin concentration <8.0 g/dL (<7.0 g/dL for patients 6 to 59 months of age)
	- Platelet count <50 × 10⁹/mL
	2. Symptomatic bone manifestations with imaging confirmation including the following:
	- Osteonecrosis
	- Fracture

Abbreviation: MN multiple of normal
^aOrgan volumes will be expressed as multiples of normal (MN) adjusted for body weight. The normal spleen volume will be computed as 2 mL/kg multiplied by weight in kilograms in patient who did not undergo any splenectomy procedure. The normal liver volume will be computed as 25 mL/kg multiplied by weight in kilograms (see the “Methods” section)