Chronic Cholangiopathy Associated with Primary Immune Deficiencies Can Be Resolved by Effective Hematopoietic Stem Cell Transplantation

The multidisciplinary approach to diagnosing inborn errors of immunity: a comprehensive review of discipline-based manifestations

INTRODUCTION

Congenital immunodeficiency is named primary immunodeficiency (PID), and more recently inborn errors of immunity (IEI). There are more than 485 conditions classified as IEI, with a wide spectrum of clinical and laboratory manifestations.

AREAS COVERED

Regardless of the developing knowledge of IEI, many physicians do not think of IEI when approaching the patient's complaint, which leads to delayed diagnosis, misdiagnosis, serious infectious and noninfectious complications, permanent end-organ damage, and even death. Due to the various manifestations of IEI and the wide spectrum of associated conditions, patients refer to specialists in different disciplines of medicine and undergo - mainly symptomatic - treatments, and because IEI are not included in physicians' differential diagnosis, the main disease remains undiagnosed.

EXPERT OPINION

A multidisciplinary approach may be a proper solution. Manifestations and the importance of a multidisciplinary approach in the diagnosis of main groups of IEI are discussed in this article.

Development of hepatic fibrosis in common variable immunodeficiency-related porto-sinusoidal vascular disorder

BACKGROUND AND AIMS

Liver involvement is an increasingly recognised complication of common variable immunodeficiency (CVID). Nodular regenerative hyperplasia (NRH), a subgroup of porto-sinusoidal vascular disorder, and manifestations of portal hypertension (PH) unrelated to cirrhosis are the most common findings. Nonetheless, the evolution of liver disease over time remains unknown.

METHODS

Retrospective review of patients followed at the National Institutes of Health with CVID-related liver disease and liver biopsy from 1990 to 2020. Clinical, imaging and histological follow-up were recorded as part of clinical research protocols.

RESULTS

Forty patients were included, with a median age of 37.5 years at initial biopsy, 73% presenting with clear evidence of NRH, and a median fibrosis stage of 1. At biopsy, median platelet count was 100 × 109/L, spleen size 19.5 cm, hepatic venous pressure gradient 9.5 mmHg and 37.5% of patients had signs of PH. Cumulative incidence of PH was 65% at 5 years. In a subgroup of 16 patients, a follow-up liver biopsy, performed at a median time of 3 years after the index biopsy, revealed an increase in fibrosis by ≥2 stages in 31% of cases and an increase to an overall stage of 2.2 (p = 0.001). No clinical or histological factors were associated with progression of fibrosis.

CONCLUSIONS

In this CVID cohort, NRH is the most common initial histological finding; however, unexpectedly fibrosis progresses over time in a subgroup of patients. A better understanding of the underlying causal process of liver disease CVID might lead to improved outcomes.

Mesenchymal stem cells: A novel treatment option for primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a progressive liver disease for which there is no effective therapy. Hepatocytes and cholangiocytes from a PSC patient were cocultured with mesenchymal stem cells (MSCs) to assess in vitro change. A single patient with progressive PSC was treated with 150 million MSCs via direct injection into the common bile duct. Coculture of MSCs with cholangiocytes and hepatocytes showed in vitro improvement. Local delivery of MSCs into a single patient with progressive PSC was safe. Radiographic and endoscopic evaluation showed stable distribution of multifocal structuring in the early postoperative period. MSCs may be effective for the treatment of PSC.

Tip of the iceberg: A comprehensive review of liver disease in Inborn errors of immunity

Inborn errors of immunity (IEIs) consist of numerous rare, inherited defects of the immune system that affect about 500,000 people in the United States. As advancements in diagnosis through genetic testing and treatment with targeted immunotherapy and bone marrow transplant emerge, increasing numbers of patients survive into adulthood posing fresh clinical challenges. A large spectrum of hepatobiliary diseases now present in those with immunodeficiency diseases, leading to morbidity and mortality in this population. Awareness of these hepatobiliary diseases has lagged the improved management of the underlying disorders, leading to missed opportunities to improve clinical outcomes. This review article provides a detailed description of specific liver diseases occurring in various inborn errors of immunity. A generalized approach to diagnosis and management of hepatic complications is provided, and collaboration with hepatologists, immunologists, and pathologists is emphasized as a requirement for optimizing management and outcomes.

A genetic screen identifies a protective type III interferon response to Cryptosporidium that requires TLR3 dependent recognition

Cryptosporidium is a leading cause of severe diarrhea and diarrheal-related death in children worldwide. As an obligate intracellular parasite, Cryptosporidium relies on intestinal epithelial cells to provide a niche for its growth and survival, but little is known about the contributions that the infected cell makes to this relationship. Here we conducted a genome wide CRISPR/Cas9 knockout screen to discover host genes that influence Cryptosporidium parvum infection and/or host cell survival. Gene enrichment analysis indicated that the host interferon response, glycosaminoglycan (GAG) and glycosylphosphatidylinositol (GPI) anchor biosynthesis are important determinants of susceptibility to C. parvum infection and impact on the viability of host cells in the context of parasite infection. Several of these pathways are linked to parasite attachment and invasion and C-type lectins on the surface of the parasite. Evaluation of transcript and protein induction of innate interferons revealed a pronounced type III interferon response to Cryptosporidium in human cells as well as in mice. Treatment of mice with IFNλ reduced infection burden and protected immunocompromised mice from severe outcomes including death, with effects that required STAT1 signaling in the enterocyte. Initiation of this type III interferon response was dependent on sustained intracellular growth and mediated by the pattern recognition receptor TLR3. We conclude that host cell intrinsic recognition of Cryptosporidium results in IFNλ production critical to early protection against this infection.

Cutting edge issues in juvenile sclerosing cholangitis

Sclerosing cholangitis (SC) is a rare chronic disorder characterised by inflammation and progressive obliterative fibrosis of the intrahepatic and/or extrahepatic bile ducts. Diagnosis is based on cholangiogram showing bile duct dilatation, narrowing and obliteration of the biliary tree, and histologically, on the presence of inflammatory bile duct damage leading to periductal fibrosis. In children the most common SC is associated with strong autoimmune features, overlapping with those of autoimmune hepatitis (AIH); this form is known as autoimmune sclerosing cholangitis, ASC. Conversely, primary SC (PSC), a condition in which the term "primary" indicates that aetiology and pathogenesis are unknown, is rare in paediatrics. Secondary SC (SSC) defines a cholangiopathy associated with an identifiable aetiology such as immunodeficiencies, infections or haematological disorders. ASC and PSC are strongly associated with inflammatory bowel disease (IBD). ASC responds biochemically well to immunosuppressive drugs and ursodeoxycholic acid (UDCA). Primary forms are exclusively managed with oral UDCA, while in the secondary forms the medical treatment depends on the underlying aetiology. Despite treatment, SC often progresses to biliary cirrhosis and end-stage liver disease requiring liver transplantation. The disease can recur after transplant. Better understanding of pathogenic mechanisms and better treatment modalities are needed to improve the prognosis of this invalidating hepatic disorder.

Disseminated Cryptosporidium infection in an infant with CD40L deficiency

The protozoan Cryptosporidium affects the digestive tract of humans and animals. Cryptosporidiosis leads to diarrhoea mimicking a cholera-like course with dehydration and may even result in death in immunodeficient patients, as patients with hyper-IgM syndrome. We describe a rare case of disseminated Cryptosporidium infection in a seven- year-old boy with CD40 L deficiency. During the pre-graft phase, the patient presented an intestinal cryptosporidiosis which became complicated few days later during the aplasia period with a cholangitis and pulmonary cryptosporidiosis. Cryptosporidium hominis was identified. After treatment with nitazoxanide and azithromycine the patient was doing well.

Complications of Cryptosporidium infection after pediatric liver transplantation: Diarrhea, rejection, and biliary disease

BACKGROUND

Cryptosporidium enteritis can be devastating in the immunocompromised host. In pediatric liver transplant recipients, infection may be complicated by prolonged carriage of the parasite, rejection, and biliary tree damage and fibrosis. Herein, we report on six patients and their long-term outcomes following cryptosporidiosis.

METHODS

We reviewed all cases of cryptosporidiosis in a pediatric liver transplant population over a 17-year period at a single center. Six patients with infection were identified, and their outcomes were analyzed.

RESULTS

Infection was associated with significant diarrhea and dehydration in all cases, and led to hospitalization in one-half of patients. Four of the six patients developed biopsy-proven rejection following infection, with three of those patients developing rejection that was recalcitrant to intravenous steroid treatment. Additionally, three patients developed biliary tree abnormalities with similarity to sclerosing cholangitis. In one patient, those biliary changes led to repeated need for biliary drain placement and advancing fibrotic liver allograft changes.

CONCLUSIONS

Cryptosporidiosis in pediatric liver transplant recipients may lead to significant complications, including recalcitrant episodes of rejection and detrimental biliary tree changes. We advocate for increased awareness of this cause of diarrheal disease and the allograft injuries that may accompany infection.

Hematopoietic Stem Cell Transplantation for Combined Immunodeficiencies, on Behalf of IEWP-EBMT

Combined immunodeficiencies (CIDs) are a clinically and genetically heterogeneous group of primary immunodeficiencies (PIDs) that affect T-lymphocyte immunity with abnormal development or function. As compared to severe combined immune deficiencies (SCID), these patients are usually diagnosed later. They display a broad infectious susceptibility; immune dysregulation manifestations and chronic lymphoproliferation are also frequent. These complications and their specific treatments can lead to persistent damage to several organs. Prognosis of CIDs is worse as compared to other PIDs. The curative treatment is usually hematopoietic stem cell transplantation (HSCT), but difficult questions remain regarding the definitive indication of HSCT and its timing; the final decision depends on a conjunction of factors such as immunological parameters, severity of clinical manifestations, and natural history of the disease, when molecular diagnosis is known. CD40L deficiency, a CID caused by mutations in CD40LG gene, well illustrates the dilemma between HSCT vs. long-term supportive treatment. This disease leads to higher risk of developing infections from bacterial and intracellular pathogens, especially Pneumocystis and Cryptosporidium spp. While supportive care allows improved survival during childhood, organ damages may develop with increasing age, mainly chronic lung disease and biliary tract disease (secondary to Cryptosporidium spp. infection) that may evolve later to sclerosing cholangitis, a severe complication associated with increased mortality. Early HSCT before organ damage development is associated with best survival and cure rate, while HSCT remains a risky therapeutic option for older patients, for those with organ damage, especially severe liver disease, and/or for those with limited or no donor availability. Prospective studies are needed to analyze risks of HSCT compared to those of life-long supportive therapy, including quality of life measures.