Primary hepatocellular carcinoma, one of the most common tumors in the world today, is occurring with increasing frequency in the United States, as shown in the study by El-Serag and Mason in this issue of the Journal. ¹ The most likely reason for this rising incidence is the spread of hepatitis virus infection in the population. Indeed, there is no better example of a tumor that is associated with persistent viral infection than hepatocellular carcinoma. Two viruses cause almost all these tumors: hepatitis B virus (HBV) and hepatitis C virus (HCV).The global distribution of hepatocellular carcinoma correlates with the geographic . . .

Helminth exposure appears to protect hosts from inappropriate inflammatory responses, such as those causing inflammatory bowel disease. A recently identified, strongly proinflammatory limb of the immune response is characterized by T cell IL-17 production. Many autoimmune type inflammatory diseases are associated with IL-17 release. Because helminths protect from these diseases, we examined IL-17 production in helminth-colonized mice. We colonized mice with Heligmosomoides polygyrus, an intestinal helminth, and analyzed IL-17 production by lamina propria mononuclear cells (LPMC) and mesenteric lymph node (MLN) cells. Colonization with H. polygyrus reduces IL-17A mRNA by MLN cells and inhibits IL-17 production by cultured LPMC and MLN cells. Helminth exposure augments IL-4 and IL-10 production. Blocking both IL-4 and IL-10, but not IL-10 alone, restores IL-17 production in vitro. Colonization of colitic IL-10-deficient mice with H. polygyrus suppresses LPMC IL-17 production and improves colitis. Ab-mediated blockade of IL-17 improves colitis in IL-10-deficient mice. Thus, helminth-associated inhibition of IL-17 production is most likely an important mechanism mediating protection from inappropriate intestinal inflammation.

Helminths down-regulate inflammation and may prevent development of several autoimmune illnesses, such as inflammatory bowel disease. We determined if exposure to the duodenal helminthHeligmosomoides polygyrusestablishes cytokine pathways in the distal intestine that may protect from intestinal inflammation. Mice received 200H. polygyruslarvae and were studied 2 weeks later. Lamina propria mononuclear cells (LPMC) were isolated from the terminal ileum for analysis and in vitro experiments. Mice withH. polygyruswere resistant to trinitrobenzenesulfonic acid (TNBS)-induced colitis, a Th1 cytokine-dependent inflammation.Heligmosomoides polygyrusdid not change the normal microscopic appearance of the terminal ileum and colon and minimally affected LPMC composition. However, colonization altered LPMC cytokine profiles, blocking gamma interferon (IFN-γ) and interleukin 12 (IL-12) p40 release but promoting IL-4, IL-5, IL-13, and IL-10 secretion. IL-10 blockade in vitro with anti-IL-10 receptor (IL-10R) monoclonal antibody restored LPMC IFN-γ and IL-12 p40 secretion. IL-10 blockade in vivo worsened TNBS colitis inH. polygyrus-colonized mice. Lamina propria CD4⁺T cells isolated from colonized mice inhibited IFN-γ production by splenic T cells from worm-free mice. This inhibition did not require cell contact and was dependent on IL-10.Heligmosomoides polygyruscolonization inhibits Th1 and promotes Th2 and regulatory cytokine production in distant intestinal regions without changing histology or LPMC composition. IL-10 is particularly important for limiting the Th1 response. The T-cell origin of these cytokines demonstrates mucosal regulatory T-cell induction.

Background Graft-versus-host-disease (GVHD) after liver transplantation (LT) is a deadly complication with very limited data on risk factors, diagnosis and management. We report a case series and a comprehensive review of the literature. Methods Data were systematically extracted from reports of GVHD after LT, and from the United Network for Organ Sharing database. Group comparisons were performed. Results One hundred fifty-six adult patients with GVHD after LT have been reported. Median time to GVHD onset was 28 days. Clinical features were skin rash (92%), pancytopenia (78%), and diarrhea (65%). Six-month mortality with GVHD after LT was 73%. Sepsis was the most common cause of death (60%). Enterobacter bacteremia, invasive aspergillosis, and disseminated Candida infections were frequently reported. Recipient age over 50 years is a risk factor for GVHD after LT. Hepatocellular carcinoma was overrepresented, whereas chronic hepatitis C was underrepresented, in reported United States GVHD cases relative to all United Network for Organ Sharing database LT cases. Mortality rate with treatment of GVHD after LT was 84% with high-dose steroids alone, 75% to 100% with regimens using dose increases of calcineurin inhibitors, and 55% with IL-2 antagonists. Mortality was 25% in small case series using the CD2-blocker alefacept or TNF-α antagonists. Conclusions Age older than 50 years and hepatocellular carcinoma appear to be risk factors for GVHD. Hepatitis C may be protective. High-dose steroids and calcineurin inhibitors are ineffective in the treatment of GVHD after LT. CD2-blockers and TNF-α antagonists appear promising. We propose a diagnostic algorithm to assist clinicians in managing adults with GVHD after LT.

Colonization with helminthic parasites induces mucosal regulatory cytokines, like IL‐10 or TGF‐β, that are important in suppressing colitis. Helminths induce mucosal T cell IL‐10 secretion and regulate lamina propria mononuclear cell (LPMC) Th1 cytokine generation in an IL‐10‐dependent manner in WT mice. Helminths also stimulate mucosal TGF‐β release. As TGF‐β exerts major regulatory effects on T lymphocytes, we investigated the role of T lymphocyte TGF‐β signaling in helminthic modulation of intestinal immunity. T cell TGF‐β signaling is interrupted in TGF‐β receptor II dominant negative (TGF‐βRII DN) mice by T‐cell‐specific over‐expression of a TGF‐βRII DN. We studied LPMC responses in WT and TGF‐βRII DN mice that were uninfected or colonized with the nematode, Heligmosomoides polygyrus. Our results indicate an essential role of T cell TGF‐β signaling in limiting mucosal Th1 and Th2 responses. Furthermore, we demonstrate that helminthic induction of intestinal T cell IL‐10 secretion requires intact T cell TGF‐β‐signaling pathway. Helminths fail to curtail robust, dysregulated intestinal Th1 cytokine production and chronic colitis in TGF‐βRII DN mice. Thus, T cell TGF‐β signaling is essential for helminthic stimulation of mucosal IL‐10 production, helminthic modulation of intestinal IFN‐γ generation and H. polygyrus‐mediated suppression of chronic colitis.