Soluble CD163 and mannose receptor as markers of liver disease severity and prognosis in patients with primary biliary cholangitis

INTRODUCTION

In primary biliary cholangitis (PBC), macrophages are involved in liver inflammation and fibrosis. The macrophage activation markers, soluble (s)CD163 and mannose receptor (sMR) are associated with liver disease severity and prognosis in other chronic liver diseases. We aimed to investigate sCD163 and sMR in patients with PBC.

METHODS

We investigated PBC patients from the Italian PBC Study Group cohort and measured macrophage activation markers in serum at study enrolment. Patients were followed from enrolment until they experienced an event or were censored at their last visit. Events were defined as follows: (a) death from a liver-related cause; or (b) liver transplantation (LT) for PBC. We used Cox regression to investigate the association between sCD163 and sMR and long-term prognosis.

RESULTS

In total, 202 PBC patients were included. Median age was 62 years (interquartile range (IQR), 53-71) at enrolment and 93% were women. Median sCD163 was 3.43 mg/L (IQR 2.48-5.35) and median sMR was 0.35 mg/L (IQR 0.28-0.45). There was an increase in sCD163 and sMR with increasing alkaline phosphatase. Two hundred and one patients were followed for a median of 8.6 years, and sCD163 and sMR predicted long-term risk of liver-related death or LT in univariate analyses, while sCD163 was also associated with outcome after confounder adjusting (adjusted HR = 1.14, 95% CI 1.00-1.30). Finally, we showed an increase in the prediction accuracy of poor outcome by adding sCD163 to the UK-PBC risk score.

CONCLUSION

The macrophage activation markers sCD163 and sMR represent a non-invasive measure of PBC disease severity that provides useful long-term prognostic information.

The activation pattern of macrophages in giant cell (temporal) arteritis and primary angiitis of the central nervous system

To determine if the pattern of macrophage activation reflects differences in the pathogenesis and clinical presentation of giant cell arteritis and primary angiitis of the central nervous system, specimens of 10 patients with giant cell arteritis and five with primary angiitis of the central nervous system were immunohistochemically studied and the expression of the macrophage activation markers 27E10, MRP14, MRP8 and 25F9 was determined in the vasculitic infiltrates. Thus, a partly different expression pattern of macrophage activation markers in giant cell arteritis and primary angiitis of the central nervous system was observed. The group comparison revealed that giant cell arteritis cases had significantly higher numbers of acute activated MRP14-positive macrophages, whereas primary angiitis of the central nervous system is characterized by a tendency toward more MRP8-positive intermediate/late activated macrophages. Furthermore, in giant cell arteritis comparably fewer CD8-positive lymphocytes were observed. These observations suggest, that despite their histopathological similarities, giant cell arteritis and primary angiitis of the central nervous system appear to represent either distinct entities within the spectrum of granulomatous vasculitides or different stages of similar disease processes. Their discrete clinical presentation is reflected by different activation patterns of macrophages, which may characterize giant cell arteritis as a more acute process and primary angiitis of the central nervous system as a more advanced inflammatory process.