A single-center experience of post-transplant lymphoproliferative disorder (PTLD) cases after pediatric liver transplantation: Incidence, outcomes, and association with food allergy.

BACKGROUND/AIMS: We evaluated our 16-year single-center experience of pediatric post-transplant lymphoproliferative disorder (PTLD) cases who underwent liver transplantation between 2001 and 2017. MATERIALS AND METHODS: Of the 236 pediatric patients who underwent liver transplantation between 2001 and 2017, the clinical and laboratory data of eight patients diagnosed with PTLD were reviewed. The pre-transplant Epstein-Barr virus (EBV) status of 172 patients was also recorded. RESULTS: The total incidence of PTLD was 3.4%. The incidence of PTLD was 10% in pre-transplant EBV immunoglobulin G (IgG)-seronegative patients and 0.8% in pre-transplant EBV IgG-seropositive patients. The mean age of the patients at liver transplantation was 2.71±3.21 years, and four patients were aged below 1 year at the time of transplantation. PTLD was diagnosed at 21.81±18.1 months after transplantation. The primary site of involvement was variable among patients: peripheral and mediastinal lymph nodes, stomach and intestine, transplanted graft, bone marrow, and nasopharynx. The eosinophil count varied greatly among patients, with a mean value of 524.62±679/mm3. Three patients had a food allergy and were administered an elimination diet at the time of PTLD diagnosis. Six patients had PTLD of B-cell origin. One patient died due to neutropenic sepsis during chemotherapy, whereas seven patients were followed up in full remission for 7.75±4 years. CONCLUSION: PTLD is a life-threatening complication of solid-organ transplantation with a heterogeneous clinical spectrum. Food allergy had a close association with PTLD. A close follow-up of patients with risk factors and an early diagnosis with appropriate treatment may lead to a better outcome.

Measles virus-derived peptide/food antigen adducts facilitate the establishment of antigen specific oral tolerance.

Allergy is a skewed T helper (Th)2 polarization response in the body; its treatment is not satisfactory currently. Oral tolerance dysfunction plays a critical role in the pathogenesis of allergy. The present study aims to restore the breached intestinal tolerance with an artificial adduct of a measles virus C protein-derived small peptide (MVCP) and a model antigen, ovalbumin (MOA), and to observe the effect of MOA on inhibition of intestinal allergy in a mouse model. The MOA was formed by the MVCP and ovalbumin. The effect of MOA on regulation of the properties of dendritic cells (DC) and CD4(+) T cells was observed with a cell culture model and a mouse model of the gut Th2 pattern inflammation. After treatment with MOA, mouse intestinal DCs showed high levels of aldehyde dehydrogenase (ALDH) activity and expressed transforming growth factor (TGF)-beta; the frequency of Treg in the intestine was also significantly increased. The treatment with MOA efficiently suppressed the antigen-specific Th2 pattern inflammation in the intestine. Administration with the MOA can induce the development of antigen-specific oral tolerance and inhibit the antigen-specific allergic reaction in the intestine. The adduct of MOA has the therapeutic potential for the allergen related immune inflammation.

Role of viruses in the development of atopic disease in pediatric patients.

The prevalence of atopic diseases continues to rise in modernized countries, without a clear explanation for this increase. One potential cause identified from epidemiologic studies of children is respiratory RNA viral infections leading to development of recurrent wheezing, asthma, and allergic sensitization. We review human epidemiologic data that both support and refute the role of viruses in this process. Exploring recent murine models, we document possible immunologic mechanisms that could translate a viral infection into atopic disease. We further discuss evidence for a post-viral "atopic cycle" that could explain the development of multiple allergen sensitization, and we explore available data to suggest a connection between viral infections of the gastrointestinal tract with the development of food allergy. Taken together, this review documents evidence to support the "viral hypothesis", and, in particular, the role of RNA viruses in the development of atopic disease.

HIV: practical implications for the practicing allergist-immunologist.

OBJECTIVES: To review the effects of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) on allergic diseases and discuss the clinical, pathophysiologic, diagnostic, and therapeutic challenges unique to HIV-infected patients receiving highly active antiretroviral therapy (HAART). DATA SOURCES: The MEDLINE and OVID databases were searched to identify pertinent articles using the following keywords: HIV, AIDS, IgE, allergic rhinitis, adverse drug reaction, asthma, chronic obstructive pulmonary disease, food allergy, and immunization. References from the chosen articles were also examined. STUDY SELECTION: Articles were selected based on their relevance to the subject matter and currency. RESULTS: Human immunodeficiency virus infection causes immunologic alterations that ultimately lead to cell-mediated immune deficiency. In addition, the immune dysfunction caused by HIV also increases the likelihood of developing allergic and other immune-mediated diseases in many patients. HAART is associated with reconstitution of immune system function. While offering protection against infection, immune reconstitution also can provoke immunopathologic conditions. Patients infected with HIV show an increased prevalence of allergic rhinitis, adverse drug reactions, and noninfectious pulmonary complications. The pathophysiology of HIV infection is associated with unique clinical, diagnostic, and therapeutic considerations when treating allergic diseases in HIV-infected patients. CONCLUSIONS: With the use of HAART and the subsequent decrease in infectious complications, HIV-infected patients now live longer and experience common chronic diseases. Evaluation of HIV-infected patients with rhinitis, asthma, and adverse drug reactions may become more frequent as HAART continues to extend the life expectancy of patients living with HIV. Understanding the interactions between HIV and these conditions can facilitate a knowledgeable approach to treating an HIV-infected patient.