Injecting drug use and hepatitis C virus infection independently increase biomarkers of inflammatory disease risk which are incompletely restored by curative direct-acting antiviral therapy.

Background: Hepatitis C virus (HCV) infections are more prevalent in people who inject drugs (PWID) who often experience additional health risks. HCV induces inflammation and immune alterations that contribute to hepatic and non-hepatic morbidities. It remains unclear whether curative direct acting antiviral (DAA) therapy completely reverses immune alterations in PWID. Methods: Plasma biomarkers of immune activation associated with chronic disease risk were measured in HCV-seronegative (n=24) and HCV RNA+ (n=32) PWID at baseline and longitudinally after DAA therapy. Adjusted generalised estimating equations were used to assess longitudinal changes in biomarker levels. Comparisons between community controls (n=29) and HCV-seronegative PWID were made using adjusted multiple regression modelling. Results: HCV-seronegative PWID exhibited significantly increased levels of inflammatory biomarkers including soluble (s) TNF-RII, IL-6, sCD14 and sCD163 and the diabetes index HbA1c as compared to community controls. CXCL10, sTNF-RII, vascular cell adhesion molecule-1 and lipopolysaccharide binding protein (LBP) were additionally elevated in PWID with viremic HCV infection as compared to HCV- PWID. Whilst curative DAA therapy reversed some biomarkers, others including LBP and sTNF-RII remained elevated 48 weeks after HCV cure. Conclusion: Elevated levels of inflammatory and chronic disease biomarkers in PWID suggest an increased risk of chronic morbidities such as diabetes and cardiovascular disease. HCV infection in PWID poses an additional disease burden, amplified by the incomplete reversal of immune dysfunction following DAA therapy. These findings highlight the need for heightened clinical surveillance of PWID for chronic inflammatory diseases, particularly those with a history of HCV infection.

Isolated positive deamidated gliadin peptide-IgG has limited diagnostic utility in coeliac disease.

AIM: Deamidated gliadin peptide-IgG (DGP-IgG) antibody serology testing is widely utilised in screening for coeliac disease in Australia; however, it is used sparingly in Europe. The aim of this study was to assess the diagnostic value of a positive DGP-IgG in the setting of a negative tissue transglutaminase-IgA (tTG-IgA) for gastrointestinal pathology among paediatric patients. METHODS: We conducted a retrospective cohort study of all children with an elevated DGP-IgG in the setting of a negative tTG-IgA who underwent gastroscopy over a 48-month period (January 2015-December 2018) at a tertiary paediatric centre. They were identified utilising the electronic pathology database and demographic and clinical data were collected from electronic medical records. Patients who had previously been diagnosed with coeliac disease were on a gluten-free diet or over the age of 18 were excluded from the study. RESULTS: Twenty-six patients with an elevated DGP-IgG in the setting of a negative tTG-IgA underwent gastroscopy. Our study yielded a positive predictive value of 1/26 (3.9% CI 95% 0.7%, 18.9%) for the diagnosis of coeliac disease. Overall, there were 25 histopathological diagnoses including 1 diagnosis of coeliac disease among the total 26 patients who were positive DGP-IgG and negative tTG-IgA and underwent gastroscopy. CONCLUSIONS: Our findings suggest that an isolated positive DGP-IgG has a very low diagnostic yield for coeliac disease in children and may be indicative of other gastrointestinal pathology.

Non-diagnostic sonography may reduce negative appendicectomy rate in women when combined with abbreviated Alvarado score.

BACKGROUND: The diagnosis of acute appendicitis (AA) remains a clinical one, with selective use of adjunct imaging. Patients with equivocal clinical presentation often undergo a diagnostic laparoscopy. To help reduce negative appendicectomy rates in women, we aimed to develop a simple scoring system based on the Alvarado score (AS) and ultrasound scan (US), as a diagnostic aid for AA in females. METHODS: All patients who underwent appendicectomy for AA at The Alfred Hospital Melbourne between 1 July 2012 and 30 June 2017 were included for this case-control study. Logistic regression was used to identify pre-operative parameters predictive of AA. Histopathological identification of AA was interpreted as the gold standard. Statistical analysis was performed using IBM SPSS Statistics V26. RESULTS: A total of 1194 patients were included, with 26% negative appendicectomy rate in women. Of the 8 parameters in the AS, logistic regression identified migratory pain, leukocytosis and leukocyte left shift as most significant predictors for AA. These three parameters were used in a 3-point test which carried a sensitivity of 92.1% and specificity of 28.7%. In women, a negative or non-diagnostic US improved the negative predictive value of the 3-point test from 57% to 82%. CONCLUSION: The 3-point abbreviated AS in combination with US may be clinically useful in women to exclude appendicitis without diagnostic laparoscopy. Further large-scale prospective studies are required to validate the utility across different subgroups.