Background Gastro-Intestinal (GI) involvement is a well-known complication of Systemic Sclerosis (SSc). Small intestinal bacterial overgrowth (SIBO) is part of such involvement. It can compromise the patient quality of life and lead to severe outcomes (cachexia, high infectious risk). However, the prevalence of SIBO is not established and predictors remain unexplored.
Objectives To estimate the prevalence of SIBO in patients with SSc exhibiting GI symptoms and identify subsets of patients at risk of SIBO regarding clinical and biological presentations and GI symptoms measured by standardised questionnaires.
Methods Between 2011 and 2012, patients with SSc exhibiting GI complaints (pain, diarrhoea, bloating) underwent glucose hydrogen/methane breath tests (BT) and blood assays (CRP, ferritin, vitamins D, B9 and B12, albumin, calcium, phosphate, prothrombin and lipid profile). At the time of the BT, patients were asked to complete two questionnaires: the Short Form-36 (SF-36) and the University of California Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument (UCLA SCTC GTI).1
Results Among 120 consecutive SSc patients, 38 patients (30 women) were included, (median age: 59 years (30-80)). Fourteen patients (37%) had a positive BT and were diagnosed with SIBO giving a point prevalence of 12% (14/120) in SSc and 37% (14/38) in SSc patients with GI symptoms. Among the 38 patients included, 18 (48%) had the diffuse cutaneous subset. Median disease duration was 8.5 years (1-35).
Patients with SIBO showed a longer disease duration (13.5 years (4-29) vs. 6.5 (1-35), p=0.007); a higher frequency of pulmonary arterial hypertension confirmed by right heart catheterization (3/14, 21% vs. 0/24, 0%, p=0.01) and a lower frequency of anti-topoisomerase-I antibodies (1/14, 7% vs. 10/24, 42%, p=0.04). Median age (60.5 vs. 59 years, p=0.5) and cutaneous subset (36% vs. 54% patients with the diffuse form, p=0.5) did not differ between patients with or without SIBO.
Of the most interest, significant weight-loss within the past 6 months (>5% of total body weight) was observed in patients with BT+ (6/14, 43% vs. 2/24, 8%, p=0.03). Despite normal median values, calcium (p=0.04), phosphate (p=0.04) and triglycerid levels (p=0.04) were lower in patients with SIBO. Focusing on GI manifestations, it is of note that the total UCLA SCTC GTI score was higher in patients suffering from SIBO (0.85 (0.24-2.22) vs. 0.30 (0.04-1.24), p=0.02). The SF-36 assessment was comparable between the 2 groups. Two patients died due to intestinal involvement with severe chronic malabsorption.
Conclusions In our series, the prevalence of SIBO was 37% of SSc patients displaying GI symptoms. To our knowledge, this is the first study using the UCLA SCTC GTI to identify patients at risk of SIBO in SSc. Higher UCLA SCTC GTI score and weight-loss appeared to be strongly associated with SIBO. These results support the systematic use of this score, together with a regular weight evaluation in SSc patients. Further studies are needed to confirm these results on a larger scale and to assess the evolution of the UCLA SCTC GTI score after SIBO optimal treatment, which is currently ongoing in our unit.
Khanna D, et al. Reliability and validity of the University of California, Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument. Arthritis Rheum 2009; 61: 1257-63.
Disclosure of Interest None Declared