Liver disease in children with primary immunodeficiencies

Clinical, immunological, and genetic description of a Mexican cohort of patients with DOCK8 deficiency

PURPOSE

We aimed to describe the clinical, immunological, and genetic features of patients with DOCK8 deficiency (DOCK8-Def) in a tertiary care center for children.

METHODS

Retrospective chart review of patients' clinical, immunological, and genetic characteristics with DOCK8-Def. Genetic analysis was performed with targeted- or whole-exome sequencing; we also assessed DOCK8 protein expression and a lymphoproliferation assay and analyzed survival by the Kaplan-Meier method.

RESULTS

We described 11 patients from 8 unrelated kindreds. The median age at symptoms' onset was 10 months (range 1-54 months). The median follow-up time was 53.4 months (4.8-118.8). All patients presented eczema and recurrent sinopulmonary and cutaneous infections. Besides those symptoms, the most frequent manifestations were bronchiectases (8/11), food allergies (6/11), and severe infections (6/11). Infrequent characteristics were detection of CMV in bronchial lavage, C. parvum-driven sclerosing cholangitis, Takayasu vasculitis, neurological syndromes, pulmonary tuberculosis, and lymphomatoid granulomatosis.

CONCLUSION

DOCK8-Def has a broad spectrum of manifestations, including allergy, autoimmunity, inflammation, infection, and cancer. The hallmark of this inborn error of immunity is IEI-associated eczema with eosinophilia and increased IgE. Here, we report six new mutations causing human DOCK8 deficiency and symptoms previously unrecognized to occur in DOCK8-Def. Therefore, an early diagnosis of DOCK8-Def is essential to facilitate an adequate treatment such as HSCT.

Primary Immunodeficiencies in Children Initially Admitted with Gastrointestinal/Liver Manifestations

Purpose

The gastrointestinal system is the most commonly affected organ, followed by the lungs, in patients with primary immunodeficiency disease (PID). Hence, it is common for children with PIDs to present with gastrointestinal symptoms. We aimed to analyze the clinical and histopathological findings of patients who were initially admitted to pediatric gastroenterology/hepatology clinics and subsequently diagnosed with PIDs to identify the clinical clues for PIDs.

Methods

The demographic, laboratory, and histopathological findings, treatment modality, and outcomes of patients initially admitted to the pediatric gastroenterology/hepatology unit and subsequently diagnosed with PIDs were recorded.

Results

The study included 24 patients (58.3% male; median age [range]: 29 [0.5-204] months). Common clinical presentations included chronic diarrhea (n=8), colitis (n=6), acute hepatitis (n=4), and acute liver failure (n=2). The association of autoimmune diseases, development of malignant diseases, and severe progression of viral diseases was observed in 20.8%, 8.3%, and 16.6% of the patients, respectively. Antibody deficiency was predominantly diagnosed in 29.2% of patients, combined immunodeficiency in 20.8%, immune dysregulation in 12.5%, defects in intrinsic and innate immunity in 4.2%, autoinflammatory disorders in 8.3%, and congenital defects of phagocytes in 4.2%. Five patients remained unclassified (20.8%).

Conclusion

Patients with PIDs may initially experience gastrointestinal or liver problems. It is recommended that the association of autoimmune or malignant diseases or severe progression of viral diseases provide pediatric gastroenterologists some suspicion of PIDs. After screening using basic laboratory tests, genetic analysis is mandatory for a definitive diagnosis.

A case of septic shock due to delayed diagnosis of Cryptosporidium infection after liver transplantation

BACKGROUND

Cryptosporidium is recognized as a significant pathogen of diarrhea disease in immunocompromised hosts, and studies have shown that Cryptosporidium infection is high in solid organ transplantation (SOT) patients and often has serious consequences. Because of the lack of specificity of diarrheasymptoms cased by Cryptosporidium infection, it is rarely reported in patients undergoing liver transplantation (LT). It frequently delays diagnosis, coming with severe consequences. In clinical work, diagnosing Cryptosporidium infection in LT patients is also complex but single, and the corresponding anti-infective treatment regimen has not yet been standardized. A rare case of septic shock due to a delayed diagnosis of Cryptosporidium infection after LT and relevant literature are discussed in the passage.

CASE PRESENTATION

A patient who had received LT for two years was admitted to the hospital with diarrhea more than 20 days after eating an unclean diet. After failing treatment at a local hospital, he was admitted to Intensive Care Unit after going into septic shock. The patient presented hypovolemia due to diarrhea, which progressed to septic shock. The patient's sepsis shock was controlled after receiving multiple antibiotic combinations and fluid resuscitation. However, the persistent diarrhea, as the culprit of the patient's electrolyte disturbance, hypovolemia, and malnutrition, was unsolved. The causative agent of diarrhea, Cryptosporidium infection, was identified by colonoscopy, faecal antacid staining, and blood high-throughput sequencing (NGS). The patient was treated by reducing immunosuppression and Nitazoxanide (NTZ), which proved effective in this case.

CONCLUSION

When LT patients present with diarrhea, clinicians should consider the possibility of Cryptosporidium infection, in addition to screening for conventional pathogens. Tests such as colonoscopy, stool antacid staining and blood NGS sequencing can help diagnose and treat of Cryptosporidium infection early and avoid serious consequences of delayed diagnosis. In treating Cryptosporidium infection in LT patients, the focus should be on the patient's immunosuppressive therapy, striking a balance between anti-immunorejection and anti-infection should be sought. Based on practical experience, NTZ therapy in combination with controlled CD4 + T cells at 100-300/mm³ was highly effective against Cryptosporidium without inducing immunorejection.

[Hyper-IgM syndrome with early liver involvement]

INTRODUCTION

Hyper-IgM syndrome is an innate error of immunity in which there is a defect in change of isotype of immunoglobulins, with decreased values of IgG, IgA, and IgE, but normal or increased level of IgM. This predisposes to infectious processes at the respiratory and gastrointestinal levels, as well as autoimmune diseases and neoplasm.

CASE REPORT

A 5 year 7-month-old boy with a history of 2 pneumonias, one of them severe, and chronic diarrhea since he was 2 years old. Persistent moderate neutropenia decreased IgG and elevated IgM. Cytometry flow confirmed absence of CD40L. Clinical evolution with early hepatic involvement.

DISCUSSION

Hyper-IgM syndrome predisposes to liver damage, so a complete evaluation is required as well as early diagnosis. Active anti-infective treatment and control of the inflammatory response are key to the treatment of liver damage.

[Combined immunodeficiency due to DOCK8 deficiency. State of the art]

Combinedimmunodeficiency (CID) due to DOCK8 deficiency is an inborn error of immunity (IBD) characterized by dysfunctional T and B lymphocytes; The spectrum of manifestations includes allergy, autoimmunity, inflammation, predisposition to cancer, and recurrent infections. DOCK8 deficiency can be distinguished from other CIDs or within the spectrum of hyper-IgE syndromes by exhibiting profound susceptibility to viral skin infections, associated skin cancers, and severe food allergies. The 9p24.3 subtelomeric locus where DOCK8 is located includes numerous repetitive sequence elements that predispose to the generation of large germline deletions and recombination-mediated somatic DNA repair. Residual production DOCK8 protein contributes to the variable phenotype of the disease. Severe viral skin infections and varicella-zoster virus (VZV)-associated vasculopathy, reflect an essential role of the DOCK8 protein, which is required to maintain lymphocyte integrity as cells migrate through the tissues. Loss of DOCK8 causes immune deficiencies through other mechanisms, including a cell survival defect. In addition, there are alterations in the response of dendritic cells, which explains susceptibility to virus infection and regulatory T lymphocytes that could help explain autoimmunity in patients. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment; it improves eczema, allergies, and susceptibility to infections.

Gut inflammation in CVID: causes and consequences

INTRODUCTION

There is a wide spectrum of noninfectious gastrointestinal pathology, causing considerable morbidity and mortality in CVID, where both etiology and effective therapy are under debate.

AREAS COVERED

This review will focus on the noninfectious inflammation in the GI tract in CVID patients, covering the both the upper and lower GI tract inflammation, including the liver. The controversy of the CVID enteropathy definition and that of gluten-free diet for celiac-like disease in CVID will be discussed. Furthermore, the review will cover the link between GI inflammation and GI cancer. Finally, the role of gut microbiota, IgA, and genetics and its relationship with CVID enteropathy is scrutinized. The authors reviewed literature from PubMed.

EXPERT OPINION

The heterogeneity and the unknown mechanism behind CVID enteropathy, and thereby the lack of effective treatment, is one of the key challenges in the field of CVID. Celiac-like disease in CVID is due to immune dysregulation, and a gluten-free diet is therefore not indicated. Gut microbial dysbiosis and mucosal IgA can initiate systemic and local inflammation and is involved in the immune dysregulation in CVID. Considering the heterogeneity of CVID enteropathy, personalized medicine is probably the future for these patients.

Case Report: Hypomorphic Function and Somatic Reversion in DOCK8 Deficiency in One Patient With Two Novel Variants and Sclerosing Cholangitis

DOCK8 deficiency is a combined immunodeficiency due to biallelic variants in dedicator of cytokinesis 8 (DOCK8) gene. The disease has a wide clinical spectrum encompassing recurrent infections (candidiasis, viral and bacterial infections), virally driven malignancies and immune dysregulatory features, including autoimmune (cytopenia and vasculitis) as well as allergic disorders (eczema, asthma, and food allergy). Hypomorphic function and somatic reversion of DOCK8 has been reported to result in incomplete phenotype without IgE overproduction. Here we describe a case of DOCK8 deficiency in a 8-year-old Caucasian girl. The patient's disease was initially classified as autoimmune thrombocytopenia, which then evolved toward a combined immunodeficiency phenotype with recurrent infections, persistent EBV infection and lymphoproliferation. Two novel variants (one deletion and one premature stop codon) were characterized, resulting in markedly reduced, but not absent, DOCK8 expression. Somatic reversion of the DOCK8 deletion was identified in T cells. Hypomorphic function and somatic reversion were associated with restricted T cell repertoire, decreased STAT5 phosphorylation and impaired immune synapse functioning in T cells. Although the patient presented with incomplete phenotype (absence of markedly increase IgE and eosinophil count), sclerosing cholangitis was incidentally detected, thus indicating that hypomorphic function and somatic reversion of DOCK8 may delay disease progression but do not necessarily prevent from severe complications.

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.

Gastrointestinal Disorders Associated with Primary Immunodeficiency Diseases

There are now 354 inborn errors of immunity (primary immunodeficiency diseases (PIDDs)) with 344 distinct molecular etiologies reported according to the International Union of Immunological Sciences (IUIS) (Clin Gastroenterol Hepatol 11: p. 1050-63, 2013, Semin Gastrointest Dis 8: p. 22-32, 1997, J Clin Immunol 38: p. 96-128, 2018). Using the IUIS document as a reference and cross-checking PubMed ( www.ncbi.nlm.nih.pubmed.gov ), we found that approximately one third of the 354 diseases of impaired immunity have a gastrointestinal component [J Clin Immunol 38: p. 96-128, 2018]. Often, the gastrointestinal symptomatology and pathology is the heralding sign of a PIDD; therefore, it is important to recognize patterns of disease which may manifest along the gastrointestinal tract as a more global derangement of immune function. As such, holistic consideration of immunity is warranted in patients with clinically significant gastrointestinal disease. Here, we discuss the manifold presentations and GI-specific complications of PIDDs which could lead patients to seek advice from a variety of clinician specialists. Often, patients with these medical problems will engage general pediatricians, surgeons, gastroenterologists, rheumatologists, and clinical immunologists among others. Following delineation of the presenting concern, accurate and often molecular diagnosis is imperative and a multi-disciplinary approach warranted for optimal management. In this review, we will summarize the current state of understanding of PIDD gastrointestinal disease involvement. We will do so by focusing upon gastrointestinal disease categories (i.e., inflammatory, diarrhea, nodular lymphoid hyperplasia, liver/biliary tract, structural disease, and oncologic disease) with an intent to aid the healthcare provider who may encounter a patient with an as-yet undiagnosed PIDD who presents initially with a gastrointestinal symptom, sign, or problem.

Tandem Orthotopic Living Donor Liver Transplantation Followed by Same Donor Haploidentical Hematopoietic Stem Cell Transplantation for DOCK8 Deficiency

BACKGROUND

An 11-year-old girl with dedicator of cytokinesis 8 (DOCK8) deficiency was proposed for potentially curative hematopoietic stem cell transplantation (HSCT), the donor being her haploidentical mother. However, end-stage liver disease caused by chronic Cryptosporidium infection required liver transplantation before HSCT.

METHODS

Consequently, a staged approach of a sequential liver transplant followed by a HSCT was planned with her mother as the donor for both liver and HSCT.

RESULTS

The patient successfully underwent a left-lobe orthotopic liver transplant; however, she developed a biliary leak delaying the HSCT. Notably, the recipient demonstrated 3% donor lymphocyte chimerism in her peripheral blood immediately before HSCT. Haploidentical-related donor HSCT performed 2 months after liver transplantation was complicated by the development of acyclovir-resistant herpes simplex virus viremia, primary graft failure, and sinusoidal obstruction syndrome. The patient died from sinusoidal obstruction syndrome-associated multiorgan failure with Candida sepsis on day +40 following HSCT.

CONCLUSIONS

We discuss the many considerations inherent to planning for HSCT preceded by liver transplant in patients with primary immunodeficiencies, including the role of prolonged immunosuppression and the risk of infection before immune reconstitution. We also discuss the implications of potential recipient sensitization against donor stem cells precipitated by exposure of the recipient to the donor lymphocytes from the transplanted organ.

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

OBJECTIVES

To investigate effects and outcome of hematopoietic stem cell transplantation (HSCT) on sclerosing cholangitis, in pediatric patients with different primary immunodeficiencies (PIDs).

STUDY DESIGN

From databases in 2 tertiary centers for immunodeficiencies and liver disease, we have identified children with PIDs and sclerosing cholangitis, who have paired clinical, radiologic, and histologic information before and after HSCT and studied their clinical progress and outcome.

RESULTS

Seven of 13 children (53.8%) died at a median interval of 4 months (range, 3 months-5 years) after HSCT. However, 6 surviving children (46.2%) with different PIDs and less severe cholangiopathies showed an improvement in markers of liver injury within months of successful unrelated reduced intensity conditioning HSCT. The repeated native liver biopsy, performed in 4 patients at a median of 96 (range, 4-144) months post-HSCT, showed a considerable improvement. Biochemical markers of liver function in the survivors completely normalized after a median of 13 months (range, 2-48). All patients continue to have a mildly dilated extrahepatic biliary system on ultrasonography with no intrahepatic ductal changes on magnetic resonance cholangiography after a follow-up of median 18 years (range, 2-20).

CONCLUSIONS

Effective HSCT has the potential to improve biochemical and histologic features of cholangiopathy in children with PIDs, presumably by clearance of chronic infection following establishment of immune competence. However, careful patient selection is critical as advanced liver injury is often associated with serious complications and mortality.

Primary Immunodeficiency and the Gut

This article presents the most common gastrointestinal, hepatic, and pancreatic manifestations of the primary immunodeficiency diseases, including the appropriate laboratory testing, endoscopic evaluation, and recommendations for further management.

Successful Sequential Liver and Hematopoietic Stem Cell Transplantation in a Child With CD40 Ligand Deficiency and Cryptosporidium-Induced Liver Cirrhosis

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is curative in patients with primary immunodeficiencies. However, pre-HSCT conditioning entails unacceptably high risks if the liver is compromised. The presence of a recurrent opportunistic infection affecting the biliary tree and determining liver cirrhosis with portal hypertension posed particular decisional difficulties in a 7-year-old child with X-linked CD40-ligand deficiency. We aim at adding to the scanty experience available on such rare cases, as successful management with sequential liver transplantation (LT) and HSCT has been reported in detail only in 1 young adult to date.

METHODS

A closely sequential strategy, with a surgical complication-free LT, followed by reduced-intensity conditioning, allowed HSCT to be performed only one month after LT, preventing Cryptosporidium parvum recolonization of the liver graft.

RESULTS

Combined sequential LT and HSCT resolved the cirrhotic evolution and corrected the immunodeficiency so that the infection responsible for the progressive sclerosing cholangitis did not recur.

CONCLUSIONS

Hopefully, this report of the successful resolution of a potentially fatal combination of immunodeficiency and chronic opportunistic infection with end-stage organ damage in a child will encourage others to adapt a sequential transplant approach to this highly complex pathology. However, caution is to be exercised to carefully balance the risks intrinsic to transplant surgery and immunosuppression in primary immunodeficiencies.

The hyper IgM syndromes: Epidemiology, pathogenesis, clinical manifestations, diagnosis and management

Hyper Immunoglobulin M syndrome (HIGM) is a rare primary immunodeficiency disorder characterized by low or absent levels of serum IgG, IgA, IgE and normal or increased levels of serum IgM. Various X-linked and autosomal recessive/dominant mutations have been reported as the underlying cause of the disease. Based on the underlying genetic defect, the affected patients present a variety of clinical manifestations including pulmonary and gastrointestinal complications, autoimmune disorders, hematologic abnormalities, lymphoproliferation and malignancies which could be controlled by multiple relevant therapeutic approaches. Herein, the epidemiology, pathogenesis, clinical manifestations, diagnosis, management, prognosis and treatment in patients with HIGM syndrome have been reviewed.

Liver transplantation in adults with liver disease due to common variable immunodeficiency leads to early recurrent disease and poor outcome

Common variable immunodeficiency (CVID) is the most common form of primary immunodeficiency characterized by antibody deficiency, recurrent bacterial infections, and autoimmunity. Advanced chronic liver disease occurs in a subset of patients with CVID and manifests with various histological features, such as nodular regenerative hyperplasia, inflammation, fibrosis, and cholangiopathy. We present a case series characterizing the outcomes in adult patients transplanted for primary CVID-related liver disease. We discuss the unique transplantation challenges faced in this primary immunodeficiency group including susceptibility to infections and early disease recurrence. There is a statistically significant decrease in 3-year and 5-year survival after liver transplantation in those with CVID-related liver disease (55% at 3 and 5 years) compared with all-comers (89% at 3 years, 81% at 5 years), prompting a need for discussion of suitability of transplantation in this group of patients as well as methods for reducing posttransplantation risk such as scrupulous search for infectious agents and reduction of immunosuppression. Liver Transplantation 24 171-181 2018 AASLD.

Failing to Make Ends Meet: The Broad Clinical Spectrum of DNA Ligase IV Deficiency. Case Series and Review of the Literature

DNA repair defects are inborn errors of immunity that result in increased apoptosis and oncogenesis. DNA Ligase 4-deficient patients suffer from a wide range of clinical manifestations since early in life, including: microcephaly, dysmorphic facial features, growth failure, developmental delay, mental retardation; hip dysplasia, and other skeletal malformations; as well as a severe combined immunodeficiency, radiosensitivity, and progressive bone marrow failure; or, they may present later in life with hematological neoplasias that respond catastrophically to chemo- and radiotherapy; or, they could be asymptomatic. We describe the clinical, laboratory, and genetic features of five Mexican patients with LIG4 deficiency, together with a review of 36 other patients available in PubMed Medline. Four out of five of our patients are dead from lymphoma or bone marrow failure, with severe infection and massive bleeding; the fifth patient is asymptomatic despite a persistent CD4+ lymphopenia. Most patients reported in the literature are microcephalic females with growth failure, sinopulmonary infections, hypogammaglobulinemia, very low B-cells, and radiosensitivity; while bone marrow failure and malignancy may develop at a later age. Dysmorphic facial features, congenital hip dysplasia, chronic liver disease, gradual pancytopenia, lymphoma or leukemia, thrombocytopenia, and gastrointestinal bleeding have been reported as well. Most mutations are compound heterozygous, and all of them are hypomorphic, with two common truncating mutations accounting for the majority of patients. Stem-cell transplantation after reduced intensity conditioning regimes may be curative.

Early-onset inflammatory bowel disease and common variable immunodeficiency-like disease caused by IL-21 deficiency

BACKGROUND

Alterations of immune homeostasis in the gut can result in development of inflammatory bowel disease (IBD). Recently, Mendelian forms of IBD have been discovered, as exemplified by deficiency of IL-10 or its receptor subunits. In addition, other types of primary immunodeficiency disorders might be associated with intestinal inflammation as one of their leading clinical presentations.

OBJECTIVE

We investigated a large consanguineous family with 3 children who presented with early-onset IBD within the first year of life, leading to death in infancy in 2 of them.

METHODS

Homozygosity mapping combined with exome sequencing was performed to identify the molecular cause of the disorder. Functional experiments were performed to assess the effect of IL-21 on the immune system.

RESULTS

A homozygous mutation in IL21 was discovered that showed perfect segregation with the disease. Deficiency of IL-21 resulted in reduced numbers of circulating CD19(+) B cells, including IgM(+) naive and class-switched IgG memory B cells, with a concomitant increase in transitional B-cell numbers. In vitro assays demonstrated that mutant IL-21(Leu49Pro) did not induce signal transducer and activator of transcription 3 phosphorylation and immunoglobulin class-switch recombination.

CONCLUSION

Our study uncovers IL-21 deficiency as a novel cause of early-onset IBD in human subjects accompanied by defects in B-cell development similar to those found in patients with common variable immunodeficiency. IBD might mask an underlying primary immunodeficiency, as illustrated here with IL-21 deficiency.

Specificities of sclerosing cholangitis in childhood

Sclerosing cholangitis (SC) is a chronic cholestatic disease characterized by inflammation and obliterative fibrosis of the bile ducts, leading to biliary cirrhosis and ultimately to liver failure. Four main clinical forms can be distinguished in children: i) neonatal SC, most probably a genetic disease transmitted by autosomal recessive inheritance; ii) SC associated with strong features of autoimmunity (referred as autoimmune sclerosing cholangitis) with quite good response to immuno-suppression iii) primary SC of unknown etiology (i.e. without features of autoimmunity) and iv) SC secondary to various diseases, including Langerhans cell histiocytosis and immunodeficiencies. Ursodesoxycholic acid is considered the treatment of choice for all forms of SC but without proof of its effectiveness in preventing progression to secondary biliary cirrhosis. In patients with immunodeficiencies, early bone marrow transplantation is the only way to prevent secondary SC. Liver transplantation remains the only validated treatment in children with biliary cirrhosis. Recurrence of SC after liver transplantation has not been clearly demonstrated in children; however, recurrence of Langerhans cell histiocytosis with bile duct injury has been reported. For patients with severe immunodeficiency, a two-step liver then bone marrow transplantation protocol may be proposed.

Liver transplantation for severe hepatitis in patients with common variable immunodeficiency

CVID is a heterogeneous group of primary immunodeficiency diseases characterized by hypogammaglobulinemia, recurrent bacterial infections, and frequent autoimmune manifestations. The post-transplant course of liver transplant recipients with CVID is rarely described. We report two patients with CVID complicated by severe enteropathy who underwent living donor liver transplantation for liver failure because of severe hepatitis. The post-transplant course was complicated by recurrent acute rejection, leading to ductopenic rejection in one and recurrent hepatitis in the other. We reviewed the tissue samples histologically and immunohistochemically. Native livers showed submassive hepatocyte necrosis in one and cirrhotic liver with active hepatitis in the other, both with infiltration of CD8+ T cells accompanied by endothelialitis and bile duct damage; the intestine contained increased numbers of intraepithelial CD8+ T cells with apoptosis of epithelial cells. The liver allograft exhibited acute rejection, with prominent CD8+ T cells infiltrating the bile duct or endothelium. In the allograft following the diagnosis of post-transplant recurrent hepatitis, CD8+ T cells comprised the majority of infiltrating cells in portal areas spilling over into hepatic parenchyma. Our cases suggest that T cells contribute to the pathogenesis of CVID in native organs as well as allografts and may constitute evidence of T-cell deregulation in the pathogenesis of CVID.

Klatskin-like lesions

Hilar cholangiocarcinoma, also known as Klatskin tumour, is the commonest type of cholangiocarcinoma. It poses unique problems in the diagnosis and management because of its anatomical location. Curative surgery in the form of major hepatic resection entails significant morbidity. About 5-15% of specimens resected for presumed Klatskin tumour prove not to be cholangiocarcinomas. There are a number of inflammatory, infective, vascular, and other pathologies, which have overlapping clinical and radiological features with a Klatskin tumour, leading to misinterpretation. This paper aims to summarise the features of such Klatskin-like lesions that have been reported in surgical literature.

Somatic mosaicism caused by monoallelic reversion of a mutation in T cells of a patient with ADA-SCID and the effects of enzyme replacement therapy on the revertant phenotype

Patients with adenosine deaminase (ADA) deficiency exhibit spontaneous and partial clinical remission associated with somatic reversion of inherited mutations. We report a child with severe combined immunodeficiency (T-B- SCID) due to ADA deficiency diagnosed at the age of 1 month, whose lymphocyte counts including CD4+ and CD8+ T and NK cells began to improve after several months with normalization of ADA activity in Peripheral blood lymphocytes (PBL), as a result of somatic mosaicism caused by monoallelic reversion of the causative mutation in the ADA gene. He was not eligible for haematopoietic stem cell transplantation (HSCT) or gene therapy (GT); therefore he was placed on enzyme replacement therapy (ERT) with bovine PEG-ADA. The follow-up of metabolic and immunologic responses to ERT included gradual improvement in ADA activity in erythrocytes and transient expansion of most lymphocyte subsets, followed by gradual stabilization of CD4+ and CD8+ T (with naïve phenotype) and NK cells, and sustained expansion of TCRγδ+ T cells. This was accompanied by the disappearance of the revertant T cells as shown by DNA sequencing from PBL. Although the patient's clinical condition improved marginally, he later developed a germinal cell tumour and eventually died at the age of 67 months from sepsis. This case adds to our current knowledge of spontaneous reversion of mutations in ADA deficiency and shows that the effects of the ERT may vary among these patients, suggesting that it could depend on the cell and type in which the somatic mosaicism is established upon reversion.

Inflammatory disease of the bile ducts-cholangiopathies: liver biopsy challenge and clinicopathological correlation

Liver biopsy challenge and clinicopathological correlation Liver biopsy interpretation in inflammatory diseases of the bile ducts or chronic cholangiopathies may be challenging, especially for pathologists working outside referral centres, where there is a limited exposure to relatively uncommon conditions. In view of the importance of sampling errors resulting from the patchy distribution of pathognomonic bile duct injuries and the misleading absence of cholestasis in the early stages, there is a need to recognize surrogate markers and subtle changes, in particular the early periportal deposition of copper and mild biliary interface activity. Such findings may either constitute the first indication of a primarily biliary disorder or be supportive of a clinically suspected diagnosis. Histological changes common to chronic cholangiopathies are reviewed at the variable stages of development that patients may first present to clinicians. As awareness of the protean clinical manifestations is essential for histological interpretation, the major and distinctive anatomoclinical features of primary biliary cirrhosis and primary and acquired sclerosing cholangitis are revisited, together with so-called overlapping syndromes and less common variants and associations, including more recently documented conditions, such as IgG4-related disease and the rarer multidrug resistance 3 deficiency. The review stresses the importance of evaluating histological changes in conjunction with clinical information.

Current management of primary sclerosing cholangitis in pediatric patients

Primary sclerosing cholangitis (PSC) is a chronic cholestatic condition affecting the extrahepatic and intrahepatic biliary tree. The incidence is seemingly increasing in children as a result of increased use of cholangiographic screening techniques in children with inflammatory bowel disease. The clinical presentation of PSC in childhood is variable and frequently without obvious cholestatic features, and cholangiography is essential for the diagnosis of this disorder. Histologic findings may help to exclude autoimmune sclerosing cholangitis. The underlying pathogenesis remains poorly understood and, as a result, therapeutic agents that halt disease progression and improve prognosis are lacking. PSC treatment is mainly supportive and directed at controlling cholestatic symptoms and preventing complications. Ursodeoxycholic acid is helpful in inducing biochemical improvement; long-term pediatric studies to determine a benefit of this agent in young patients are lacking, although results from adult studies have not been promising. Some agents such as antibiotics are under investigation with some promising results. Liver transplantation is required for children who progress to end-stage liver disease. Prospective multicenter trials in children with PSC are needed.

Update on the hyper immunoglobulin M syndromes

The Hyper-immunoglobulin M syndromes (HIGM) are a heterogeneous group of genetic disorders resulting in defects of immunoglobulin class switch recombination (CSR), with or without defects of somatic hypermutation (SHM). They can be classified as defects of signalling through CD40 causing both a humoral immunodeficiency and a susceptibility to opportunistic infections, or intrinsic defects in B cells of the mechanism of CSR resulting in a pure humoral immunodeficiency. A HIGM picture can also be seen as part of generalized defects of DNA repair and in antibody deficiency syndromes, such as common variable immunodeficiency. CD40 signalling defects may require corrective therapy with bone marrow transplantation. Gene therapy, a potential curative approach in the future, currently remains a distant prospect. Those with a defective CSR mechanism generally do well on immunologoblulin replacement therapy. Complications may include autoimmunity, lymphoid hyperplasia and, in some cases, a predisposition to lymphoid malignancy.

Pathogenesis, diagnosis, and management of primary antibody deficiencies and infections

Primary antibody deficiencies are the most common primary immunodeficiency diseases. They are a heterogeneous group of disorders with various degrees of dysfunctional antibody production resulting from a disruption of B-cell differentiation at different stages. While there has been tremendous recent progress in the understanding of some of these disorders, the etiology remains unknown for the majority of patients. As there is a large spectrum of underlying defects, the age at presentation varies widely, and the clinical manifestations range from an almost complete absence of B cells and serum immunoglobulins to selectively impaired antibody responses to specific antigens with normal total serum immunoglobulin concentrations. However, all of these disorders share an increased susceptibility to infections, affecting predominantly the respiratory tract. A delay of appropriate treatment for some diseases can result in serious complications related to infections, while timely diagnosis and adequate therapy can significantly decrease morbidity and increase life expectancy and quality of life.

Abnormal liver function in common variable immunodeficiency disorders due to nodular regenerative hyperplasia

Patients with common variable immunodeficiency disorders are monitored for liver function test abnormalities. A proportion of patients develop deranged liver function and some also develop hepatomegaly. We investigated the prevalence of abnormalities and types of liver disease, aiming to identify those at risk and determine outcomes. The local primary immunodeficiency database was searched for patients with a common variable immunodeficiency disorder and abnormal liver function and/or a liver biopsy. Patterns of liver dysfunction were determined and biopsies reviewed. A total of 47 of 108 patients had deranged liver function, most commonly raised alkaline phosphatase levels. Twenty-three patients had liver biopsies. Nodular regenerative hyperplasia was found in 13 of 16 with unexplained pathology. These patients were more likely to have other disease-related complications of common variable immunodeficiency disorders, in particular non-coeliac (gluten insensitive) lymphocytic enteropathy. However, five had no symptoms of liver disease and only one died of liver complications. Nodular regenerative hyperplasia is a common complication of common variable immunodeficiency disorders but was rarely complicated by portal hypertension.

Clinical immunology review series: an approach to the patient with recurrent infections in childhood

Recurrent or persistent infection is the major manifestation of primary immunodeficiency, which also results in atypical infection with opportunistic organisms. Young children are also vulnerable to infection and recurrent infection is common. While most children with recurrent infection have a normal immunity, it is important to recognize the child with an underlying primary immunodeficiency and investigate and treat appropriately and yet not over investigate normal children. Prompt, accurate diagnosis directs the most appropriate treatment, and early and judicious use of prophylactic antibiotics and replacement immunoglobulin can prevent significant end organ damage and improve long-term outlook and quality of life. This paper describes important presenting features of primary immunodeficiency and indicates when further investigation is warranted.

Cryptosporidium infection in patients with primary immunodeficiencies

BACKGROUND

Cryptosporidium species infection is usually self-limited in immunocompetent populations, but can be severe and life-threatening among immunocompromised individuals, particularly in patients with AIDS and in these patients with primary immunodeficiencies (PIDs).

PATIENTS AND METHODS

A group of 5 patients with genetically confirmed hyper-IgM syndrome type 1 (XHIM) and one patient with primary CD4 lymphopenia were enrolled in the study. At least 2 stool samples and a bile sample in one patient were examined for Cryptosporidium oocysts by a modified Ziehl-Neelsen technique, by immunofluorescence assay using a commercial kit, as well as by molecular analysis followed by genotyping. Immunological status at the time of PID diagnosis and the complex picture of disease are presented.

RESULTS

Chronic cryptosporidiosis was confirmed in 3 patients with XHIM and in one patient with primary CD4 lymphopenia. Molecular diagnosis showed the presence of C parvum, C hominis, and C meleagridis in analyzed specimens.

CONCLUSIONS

Cryptosporidium infection with serious clinical symptoms observed in patients with hyper-IgM syndrome calls for regular, repeated screening in this group of patients.

Recognition, clinical diagnosis and management of patients with primary antibody deficiencies: a systematic review

The primary purpose of this systematic review was to produce an evidence-based review of the literature as a means of informing current clinical practice in the recognition, diagnosis and management of patients with suspected primary antibody deficiency. Randomized controlled trials (RCTs) were identified from a search of MEDLINE, EMBASE, The Cochrane Library, DARE (CRD website) and CINAHL by combining the search strategies with The Cochrane Collaboration's validated RCT filter. In addition, other types of studies were identified in a separate search of MEDLINE and EMBASE. Patients at any age with recurrent infections, especially in the upper and lower respiratory tracts, should be investigated for possible antibody deficiency. Replacement therapy with immunoglobulin in primary antibody deficiencies increases life expectancy and reduces infection frequency and severity. Higher doses of immunoglobulin are associated with reduced infection frequency. Late diagnosis and delayed institution of immunoglobulin replacement therapy results in increased morbidity and mortality. A wide variety of organ-specific complications can occur in primary antibody deficiency syndromes, including respiratory, gastroenterological, hepatic, haematological, neurological, rheumatological and cutaneous. There is an increased risk of malignancy. Some of these complications appear to be related to diagnostic delay and inadequate therapy. High-quality controlled trial data on the therapy of these complications is generally lacking. The present study has identified a number of key areas for further research, but RCT data, while desirable, is not always obtained easily for rare conditions. Few data from registries or large case-series have been published in the past 5 years and a greater focus on international collaboration and pooling of data is needed.

Zoonoses in Solid-Organ and Hematopoietic Stem Cell Transplant Recipients

Numerous reports exist of the transmission of zoonoses to humans during and after solid-organ and hematopoietic stem cell transplantation. Donor-derived infections of numerous etiologies, including West Nile virus infection, Chagas disease, toxoplasmosis, rabies, lymphocytic choriomeningitis virus infection, and infection due to Brucella species have been reported. Most zoonoses occur as a primary infection after transplantation, and immunocompromised patients are more likely to experience significant morbidity and mortality from these infections. Risks of zoonotic infection in the posttransplantation period could be reduced by patient education. Increased recognition of the risks of zoonoses, as well as the advent of molecular biology-based testing, will potentially augment diagnostic aptitude. Documented zoonotic infection as it affects transplantation will be the primary focus of this review.

Sclerosing cholangitis: a focus on secondary causes

Secondary sclerosing cholangitis (SSC) is a disease that is morphologically similar to primary sclerosing cholangitis (PSC) but that originates from a known pathological process. Its clinical and cholangiographic features may mimic PSC, yet its natural history may be more favorable if recognition is prompt and appropriate therapy is introduced. Thus, the diagnosis of PSC requires the exclusion of secondary causes of sclerosing cholangitis and recognition of associated conditions that may potentially imitate its classic cholangiographic features. Well-described causes of SSC include intraductal stone disease, surgical or blunt abdominal trauma, intra-arterial chemotherapy, and recurrent pancreatitis. However, a wide variety of other associations have been reported recently, including autoimmune pancreatitis, portal biliopathy, eosinophillic and/or mast cell cholangitis, hepatic inflammatory pseudotumor, recurrent pyogenic cholangitis, primary immune deficiency, and AIDS-related cholangiopathy. This article offers a comprehensive review of SSC.

Primary sclerosing cholangitis: summary of a workshop

Primary sclerosing cholangitis (PSC) is a rare but important liver disease that leads to cirrhosis and need for liver transplantation in a high proportion of cases. The disease occurs in approximately 1 per 100,000 population per year, usually presents in adulthood, and affects men more often than women. Typical serum biochemical results, autoantibodies and liver biopsy are suggestive but not diagnostic of PSC, the diagnosis requiring cholangiographic demonstration of stricturing and dilatation of the intra- and/or extra-hepatic bile ducts. The natural history of PSC is variable, the average survival being 12 to 17 years. The cause of PSC is still unknown. Although considered an autoimmune disease, PSC has several atypical features and a strong genetic component. The therapy of PSC is unsatisfactory. Standard doses of ursodeoxycholic acid (UDCA) lead to improvements in biochemical abnormalities but not in histology, cholangiographic appearance or survival. Several innovative therapies have been tried in PSC, but with scant evidence of benefit. For patients with high grade strictures, endoscopic dilatation is beneficial. Liver transplantation is successful for end-stage liver disease due to PSC and improves survival. PSC may recur after transplantation but is rarely progressive. The most dreaded complication of PSC is cholangiocarcinoma. Diagnosis of this highly malignant tumor is difficult, and there are no biomarkers for its early detection. Liver transplantation for cholangiocarcinoma has an exceedingly poor outcome, although transplantation with neoadjuvant chemoirradiation holds promise in selected patients. Thus, significant opportunities remain for basic and clinical research into the cause, natural history, and therapy of PSC.

Sclerosing cholangitis

PURPOSE OF REVIEW

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by strictures of the biliary tree. It is immune mediated, although the precise cause remains unknown. Recent reports have shown a higher prevalence and burden of disease than was previously suspected.

RECENT FINDINGS

The research into the etiopathogenesis, epidemiology, diagnosis of cholangiocarcinoma, medical and surgical therapy, and timing and outcome of liver transplantation is discussed.

SUMMARY

Genetic heterogeneity among patients with primary sclerosing cholangitis is supported, and further gene polymorphisms associated with protection against primary sclerosing cholangitis have been elucidated. Bile duct injury seems to be a multistep process. Magnetic resonance cholangiopancreatography is a cost-effective and accurate way of diagnosing primary sclerosing cholangitis in comparison with endoscopic retrograde cholangiopancreatography. Ursodeoxycholic acid may have a role as a colorectal and hepatobiliary cancer chemopreventive agent. Liver transplantation remains the only treatment in end-stage disease. The 5-year and 10-year patient and graft survival rates are comparable with those in patients without primary sclerosing cholangitis, but there is a higher rate of retransplantation for primary sclerosing cholangitis in most centers. Hepatobiliary malignancy is found in a minority of patients at transplantation, although 5-year survival rates for these patients are still promising.