Non-invasive diagnosis of alcohol-related steatohepatitis in patients ongoing alcohol withdrawal based on cytokeratin 18 and transient elastography

BACKGROUND AND AIMS

The diagnosis of alcoholic steatohepatitis (ASH) is based on liver biopsy, which is costly and invasive with non-negligible morbidity. The aim of this study was to evaluate the accuracy of circulating cytokeratin 18 M65 fragment (K18-M65) alone or in association with other markers for the non-invasive diagnosis of ASH in patients ongoing alcohol withdrawal.

METHODS

This study examined the serum level of K18-M65 in a test cohort of 196 patients. All patients underwent liver biopsy, transient elastography (TE) and serum collection. The diagnostic accuracy of K18-M65 alone or combined with clinico-biological data was assessed and the best defined cut-offs were validated in an independent validation cohort of 58 patients.

RESULTS

K18-M65 had an area under the curve (AUC) of 0.82 (test cohort) and 0.90 (validation cohort). Using two cut-off decision points, K18-M65 was able to classify 46.9% (test cohort) and 34.5% (validation cohort) of patients with 95% sensitivity or specificity. Combining K18-M65, alpha-2-macroglobulin, TE, body mass index, and age, we created a score allowing accurate diagnosis of ASH with an AUC of 0.93 (test cohort) and 0.94 (validation cohort). This new score was able to rule out or rule in the diagnosis of steatohepatitis for probability ≤0.135 or ≥0.667 respectively in more than two-thirds of patients.

CONCLUSIONS

We propose a new validated non-invasive score for the diagnosis of ASH in patients ongoing alcohol withdrawal. This score can help to identify patients that may benefit from potential therapeutics or motivate them to reduce alcohol consumption.

Evaluation of a new rapid immunochromatographic assay for the detection of GES-producing Gram-negative bacteria

BACKGROUND

As carbapenemase-producing Enterobacterales are increasingly reported worldwide, their rapid detection is crucial to reduce their spread and prevent infections and outbreaks. Lateral flow immunoassays (LFIAs) have become major tools for the detection of carbapenemases. However, as for most commercially available assays, only the five main carbapenemases are targeted.

OBJECTIVES

Here, we have developed and evaluated an LFIA prototype for the rapid and reliable detection of the increasingly identified GES-type β-lactamases.

METHODS

The GES LFIA was validated on 103 well-characterized Gram-negative isolates expressing various β-lactamases grown on Mueller-Hinton (MH) agar, chromogenic, and chromogenic/selective media.

RESULTS

The limit of detection of the assay was 106 cfu per test with bacteria grown on MH agar plates. GES LFIA accurately detected GES-type β-lactamases irrespective of the culture media and the bacterial host. The GES LFIA was not able to distinguish between GES-ESBLs and GES-carbapenemases. Because GES enzymes are still rare, their detection as an ESBL or a carbapenemase remains important, especially because extensive use of carbapenems to treat ESBL infections may select for GES variants capable of hydrolysing carbapenems.

CONCLUSIONS

The GES LFIA is efficient, rapid and easy to implement in the routine workflow of a clinical microbiology laboratory for the confirmation of GES-type β-lactamases. Combining it with immunochromatographic assays targeting the five main carbapenemases (KPC, NDM, VIM, IMP and OXA-48) would improve the overall sensitivity for the most frequently encountered carbapenemases and ESBLs, especially in non-fermenters.

The anti-fibrotic role of mast cells in the liver is mediated by HLA-G and interaction with hepatic stellate cells

BACKGROUND & AIMS

We have reported a significant association between HLA-G expression or the number of hepatic mast cells and liver fibrosis. Here, we investigated the role of HLA-G and mast cells in liver fibrosis, focusing, in particular, on interactions between human mast and stellate cells.

METHODS

Human mast cells (HMC cell line, CD34-derived mast cells, or tissue-derived mast cells) were co-cultured with purified human hepatic stellate cells (HSCs), and collagen I production by HSCs was evaluated. Mast cells and HSCs were characterized by immunocytochemistry. Various conditions were tested: different times in direct or indirect contact, presence or absence of cytokines, addition or not of HLA-G, and presence or absence of specific protease inhibitors.

RESULTS

The reciprocal interaction between HSCs and mast cells led to the attraction of mast cells to HSCs in vivo and in vitro, and to a significant decrease in collagen production, at all times of co-culture, following the direct or indirect contact of mast cells with HSCs alone or in the presence of TGF-β, IFN-α or IL-10. We identified the diffusible factors involved in collagen I degradation as mast cell proteases. Moreover, HLA-G expression increased during the co-culture of HSCs and mast cells, with HLA-G acting on both mast cells and HSCs, to enhance collagen I degradation.

CONCLUSIONS

Mast cells play a beneficial, anti-fibrotic role in liver fibrosis, via the HLA-G-mediated decrease of collagen I. These findings are consistent with high levels of cross-communication between mast cells and hepatic stellate cells and the role of HLA-G.