Background Scleroderma bowel involvement is a problematic symptoms and cause loss of quality of life. There is no non-invasive and useful tool for diagnosis and clinical parameter of bowel involvements in patients with systemic sclerosis (SSc).
Objectives To determine the quantitative analysis of the severity of gastrointestinal involvements of patients with SSc, we measured serum FGF19 superfamily (FGF19, FGF21) and 13C labeled fatty acid absorption-breath test in patients with systemic sclerosis (SSc). We observed the production of serum FGF19 and intestinal lipid absorption test by 13C-fatty acids breath test. FGF19 produced from ileum has a hormone like function and regulate the bile acid synthesis by entero-hepatic negative feedback loop. FGF21 produced in liver and regulate lipid metabolism and absorption.
Methods 33 patients with SSc were mean age 51.9±13.9 year-old, disease duration 6.3±4.2 years, Diffuse cutaneous SSc21, limited cutaneous SSc12. 13C-fatty acid absorption breath test were examined in 33 patients with SSc and age sex matched 20 normal healthy control. FGF19 and FGF21 were measured in serum from these SSc and normal subjects by enzyme-Linked Immunosorbent assay (ELISA). 13C-fatty acid breath test: 13C-mixed fatty acids 200mg were given orally and exhaled air were collected at appropriate intervals for the analysis of 13CO2 contents by a mass spectrometer. Using breath test data, fatty acid absorption was calculated by cumulative13C excretion for 8 hours.
Results The level of FGF19 in fasting serum of patients with SSc were significantly lower than that of normal healthy subjects (SSc: 140.9±92.6pg/ml, normal: 211.0±78.8pg/ml, p<0.05). There is no difference in FGF21 serum concentration between SSc and normal subjects. These FGF19 serum levels correlated with the scleroderma bowel severity scale. Grade 1 (symptoms appeared): 172.6±93, Grade 2 (antibiotics needed): 140.9±35.3, Grade 3 (pseudo-obstruction): 64.4±35.8pg/ml, Grade 4 (Intravenous hyperalimentation needed): 8.8±13.8pg/ml. 8 hours 13CO2 cumulative recovery ratio indicated fatty acid absorption rate from intestine in 13C-fatty acid absorption breath test. 13C-cumulative excretion for 8 hours in patients with SSc was significantly lower than that of normal subjects (33 SSc patients: 12±6%, normal: 21±4%). 13C-cumulative excretion rate was correlated with a disease severity scale. Level of serum FGF19 was correlated with 8 hours 13C-cumulative excretion rate in 13C-fatty acids absorption breath test. Both serum level of FGF19 and 8 hours 13C-cumulative excretion rate increased after treatment by antibiotics and prokinetic drugs.
Conclusions These data suggested serum level of enteric hormone FGF19 and13C-fatty acid absorption breath test were non-invasive and useful new tools and clinical new parameters of severe bowel involvements in patients with SSc.
Disclosure of Interest None Declared