Extremely high serum level of IgE during immunosuppressive therapy: paradoxical effect of cyclosporine A and tacrolimus

Topical therapy and skin care for transplant-associated atopic dermatitis in children and adolescents

BACKGROUND

New-onset allergic diseases, such as food allergy or atopic dermatitis, can develop after allogeneic transplantation. There are limited reports of new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation in children and adolescents, and its treatment is yet to be established. The pathogenesis may differ from typical atopic dermatitis in terms of alloimmunity including graft-versus-host disease.

METHODS

We present five children and adolescents with new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation. The characteristics and clinical profiles of skin treatment after hematopoietic stem cell transplantation are summarized.

RESULTS

Graft-versus-host disease prophylaxis included systemic tacrolimus for all patients. After hematopoietic stem cell transplantation, all patients achieved complete donor chimerism of the bone marrow and had acute graft-versus-host disease of the skin. After engraftment, all patients had skin lesions that met the international consensus diagnostic criteria for atopic dermatitis. None of the patients met the diagnostic criteria for chronic graft-versus-host disease. Topical therapy and skin care based on atopic dermatitis guidelines improved skin condition and atopic dermatitis severity scores in all patients. In addition, type 2 inflammatory markers improved accordingly.

CONCLUSION

Topical therapy and skin care may be effective for transplant-related atopic dermatitis after hematopoietic stem cell transplantation. When extensive dermatitis is observed after hematopoietic stem cell transplantation, this treatment may avoid excessive immunosuppressive therapy if it meets the diagnostic criteria for atopic dermatitis.

Chronic calcium signaling in IgE+ B cells limits plasma cell differentiation and survival

In contrast to other antibody isotypes, B cells switched to IgE respond transiently and do not give rise to long-lived plasma cells (PCs) or memory B cells. To better understand IgE-BCR-mediated control of IgE responses, we developed whole-genome CRISPR screening that enabled comparison of IgE⁺ and IgG1⁺ B cell requirements for proliferation, survival, and differentiation into PCs. IgE⁺ PCs exhibited dependency on the PI3K-mTOR axis that increased protein amounts of the transcription factor IRF4. In contrast, loss of components of the calcium-calcineurin-NFAT pathway promoted IgE⁺ PC differentiation. Mice bearing a B cell-specific deletion of calcineurin B1 exhibited increased production of IgE⁺ PCs. Mechanistically, sustained elevation of intracellular calcium in IgE⁺ PCs downstream of the IgE-BCR promoted BCL2L11-dependent apoptosis. Thus, chronic calcium signaling downstream of the IgE-BCR controls the self-limiting character of IgE responses and may be relevant to the accumulation of IgE-producing cells in allergic disease.

Development of New White Fish Allergy after Bone Marrow Transplantation from a Non-atopic Donor

Background: Transplant-acquired food allergy has become increasingly recognized in solid organ and bone marrow transplantation. As food allergy has no cure and causes considerable impact on the lives of patients who require strict avoidance of foods to avoid potentially severe or fatal reactions, it is crucial for physicians to better understand the risk factors and mechanisms driving development of food allergy post-transplant. We report a case of new food allergy to whitefish in an elderly patient post-bone marrow transplant in which neither donor nor recipient had a history of atopy. Methods: A 70-year-old man experienced an anaphylactic reaction to Swai whitefish (Pangasius hypophthalmus) 6 months post-transplant that he had previously tolerated on multiple occasions both pre-transplant and in the preceding months post-transplant. This allergy was investigated by commercial serum specific IgE testing and fresh prick-to-prick skin test to Swai whitefish. Results: Fresh prick-to-prick demonstrated large positive reaction to the Swai whitefish with wheal of 10 mm and flare of 22 mm compared to positive histamine control with a wheal/flare of 5x8mm. Serum specific IgE testing to commercial whitefish was negative (specific IgE <0.10kU/L). The patient continues to strictly avoid Swai whitefish but tolerates all other fish and shellfish. Conclusions: The unique development of specific Swai whitefish allergy in an elderly man after bone marrow transplant where both donor and recipient had no prior history of atopy strongly supports transplant-related immunomodulation as a major mechanism for transplant-acquired allergy and suggests that that absence of atopy or advanced age may not necessarily be protective.

Calcineurin inhibitors dampen humoral immunity by acting directly on naive B cells

Calcineurin inhibitors (CNI), used frequently in solid organ transplant patients, are known to inhibit T cell proliferation, but their effect on humoral immunity is far less studied. Total and naive B cells from healthy adult donors were cultured in immunoglobulin (Ig)A- or IgG/IgE-promoting conditions with increasing doses of cyclosporin, tacrolimus, rapamycin or methylprednisolone. The effect on cell number, cell division, plasmablast differentiation and class-switching was tested. To examine the effect on T follicular helper (Tfh) cell differentiation, naive CD4(+) T cells were cultured with interleukin (IL)-12 and titrated immunosuppressive drug (IS) concentrations. Total B cell function was not affected by CNI. However, naive B cell proliferation was inhibited by cyclosporin and both CNI decreased plasmablast differentiation. Both CNI suppressed IgA, whereas only cyclosporin inhibited IgE class-switching. Rapamycin had a strong inhibitory effect on B cell function. Strikingly, methylprednisolone, increased plasmablast differentiation and IgE class-switching from naive B cells. Differentiation of Tfh cells decreased with increasing IS doses. CNI affected humoral immunity directly by suppressing naive B cells. CNI, as well as rapamycin and methylprednisolone, inhibited the in-vitro differentiation of Tfh from naive CD4(+) T cells. In view of its potent suppressive effect on B cell function and Tfh cell differentiation, rapamycin might be an interesting candidate in the management of B cell mediated complications post solid organ transplantation.

New developments in transplant-acquired allergies

Transplant-acquired allergy (TAA) was firstly described as transplant-acquired food allergy (TAFA) after bone marrow transplantations and mostly observed in a transient form. The picture is complicated by numerous case reports of TAFA after the receipt of liver grafts from donors with no documented history of food allergy. The estimated prevalence of TAFA among young children in the literature has been documented in various studies ranging from 6% to 57%. Although TAA is mostly found to be associated with liver transplantation; it has been recently reported to be related with heart, intestinal, lung and even renal transplantations in adults. Previous reviews of published cases of liver TAA misleadingly emphasized the predominance of children and the absence of TAA in cardiac, pulmonary, and renal transplant recipients. In different studies, the male/female ratio is equal. Literature data suggest that children with TAFA typically present within the first year after surgery and are typically allergic to multiple foods. The pathogenesis of TAA is not still completely understood. Most of the studies support the concept that the functioning liver itself, and not only tacrolimus immunosuppression, is one of the main contributors to TAA in these patients. In the light of recent findings, other possible mechanisms can be summarized as following: (1) the recovery of delayed type hypersensitivity; (2) late manifestation of food allergy; (3) intestinal injury as well as inhibition of cellular energy production by tacrolimus; and (4) transfer of food-specific IgE or lymphocytes. Thus, interplay between hematopoietic cells from the transplanted organ and recipient specific factors (e.g., younger age and atopic background) seem to underlie the development of TAA. Most patients will have symptomatic improvement following reduced immunosuppression and an appropriately restricted diet. Nevertheless, some studies suggest that atopic diseases occur in some of pediatric liver transplant recipients, with manifestations including food allergy, eczema, allergic rhinitis, and asthma. More studies would be needed including greater number of patients to determine whether TAA is transient or not in pediatric/adult solid organ recipients.

Presentation of atopic disease in a large cohort of pediatric liver transplant recipients

Atopic disease occurs in solid organ transplant recipients with an increasingly recognized frequency. The time course for the development of these atopic diseases in liver transplantation has not been described. The objective was to characterize the atopic manifestations of children receiving chronic immunosuppression after orthotopic liver transplantation (OLT). Chart review and follow-up questionnaire were utilized for 176 OLT pediatric recipients at a single institution for manifestations of allergic disease. Atopic disease was present in 25 (14.2%) patients. Median age at transplant was 16 months with a median follow-up of 63 months. Food allergy and non-food related atopic symptoms presented at a median of 11.5 (IQR, 6-28) and 19 (IQR, 5-41) months post-transplantation, respectively. The median age at transplant of the non-atopic children was 72 months, higher than patients with atopy (p < 0.001). Food allergy and atopic skin disease symptoms were present in 40% and 56% of cases, respectively. Asthma, allergic rhinitis, or both were found in 66% of cases. The onset of symptoms of food allergy and eczema (median, 12 months post-transplantation) preceded symptoms of allergic rhinitis and asthma. (median of 27 and 30 months post-transplantation, respectively). Atopy occurs in ∼14% of pediatric liver transplant recipients, with manifestations including food allergy, eczema, allergic rhinitis, and asthma.

Transfer of peanut allergy following lung transplantation: a case report

This case study describes a patient who developed peanut allergy following lung transplantation. A 54-year-old woman underwent bilateral lung transplantation on June 2009 owing to severe chronic obstructive pulmonary disease. She had no history of food allergy before transplantation. The donor, however, was a 20-year-old man who was fatally injured during an automobile accident; he was allergic to peanuts. At 3 months after transplantation, the lung recipient presented with acute dyspnea and urticaria 15 minutes after consuming food containing peanut derivatives. Pre- and posttransplantation recipient blood samples analyzed for the presence of IgE antibodies specific for peanut allergens confirmed that the allergy had been passively transfered as a consequence of transplantation. Food allergy following solid organ transplantation is thought to be rare, mostly occurring in children. Two mechanisms may explain the observations described for the patient reported in this study: de novo development of peanut allergies after transplantation, or passive transfer of peanut allergies from a peanut-sensitized organ donor. This case report documenting pre- and posttransplantation IgE status in a lung transplantation case suggested that the allergic status of organ donors should be thoroughly assessed before transplantation, and potential allergy transfer risks must be discussed with the transplant team and the patient.

Topical application of Rehmannia glutinosa extract inhibits mite allergen-induced atopic dermatitis in NC/Nga mice

AIM OF THE STUDY

Rehmannia glutinosa is known in Asia as a traditional herbal medicine with anti-inflammatory properties. Atopic dermatitis (AD) is an inflammatory skin disease associated with enhanced T-helper 2 (Th2) lymphocyte responses to allergens that results in elevated serum IgE levels and leukocyte infiltration. Although some studies have shown that Rehmannia glutinosa extract (RGE) has anti-inflammatory and anti-allergic activities, these properties have not been demonstrated in AD. This study investigated the effectiveness of RGE as a therapeutic candidate in an AD model as well as its underlying mechanism of action.

MATERIALS AND METHODS

The effects of RGE on mite allergen (Dermatophagoides farinae)-treated NC/Nga mice were evaluated by skin symptom severity, ear thickness, production of serum IgE and histamine, and expression of cytokines, chemokines, and adhesion molecules in the ear lesions. In addition, the levels of thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC), and regulated on activation, normal T cell expressed and secreted (RANTES) produced in both TNF-α- and IFN-γ-stimulated human keratinocytes were investigated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

RGE treatment of NC/Nga mice significantly reduced dermatitis scores, ear thicknesses, and serum histamine levels. Histological analyses demonstrated decreased thickening of the epidermis/dermis as well as dermal infiltration by inflammatory cells. In the ear lesions, mRNA expression levels of IL-4, TNF-α, VCAM-1, and ICAM-1 were inhibited by RGE treatment. RGE also suppressed the production of TARC, MDC, and RANTES in both the ear lesions and keratinocytes.

CONCLUSIONS

RGE inhibits the development of AD in NC/Nga mice by suppressing the expression of cytokines, chemokines, and adhesion molecules.

Impact of systemic immuno-suppression after solid organ transplantation on allergen-specific responses

INTRODUCTION

  The immunosuppressive therapy in solid organ transplantation targets mainly the T- and B-cell-mediated immune response. However, there is evidence that it neither suppresses sensitization nor clinical manifestation of allergic diseases in organ-transplanted patients.

OBJECTIVE

  This study addresses the question whether allergen-specific responses are altered by systemic immunosuppression via negative effects on the T-regulatory cell compartment and a more pronounced suppression on Th1-type T-cell responses.

MATERIAL AND METHODS

  Peripheral blood mononuclear cells from 65 solid organ-transplanted (kidney, liver, lung) children, adolescents, and young adults and 18 healthy, matched controls were included, and their clinical and sensitization status assessed. Allergen-specific proliferation, intracellular cytokine production, frequency of forkhead box P3 (FOXP3)+ CD3+ CD4+ CD25(high) cells, mRNA expression of IL-10, transforming growth factor (TGF)-β and FOXP3 (real-time RT-PCR) of peripheral blood mononuclear cells or bronchoalveolar lavage fluid (BAL)-derived cells, and the inhibitory capacity of T-reg cells were investigated.

RESULTS

  Immunosuppression led to a significantly altered regulatory marker profile expressed by enhanced TGF-β mRNA production and a reduced frequency of FOXP3+ CD4+ CD3+ cells in solid organ transplanted individuals. FOXP3 expression in BAL cells of lung-transplanted patients was significantly decreased. Allergen-specific proliferation was not significantly altered despite long-term immunosuppression. However, suppression of allergen-specific responses via the T-regulatory cell fraction was deficient in immunosuppressed individuals.

CONCLUSION

  The results suggest an insufficient control of allergen-specific responses via the Treg-cell compartment under systemic immunosuppression.

Food allergy after liver transplantation in children: a prospective study

Food allergy has been increasingly reported in children who had orthotopic liver transplantation (OLT). We aimed to conduct a prospective study to investigate the prevalence of sensitizations and food allergy in pediatric OLT recipients. We also aimed to identify potential risk factors. The study group consisted of 28 children (14 male, 14 female, mean age 4.96 +/- 0.76 yrs) who had OLT. Total eosinophil count (TEC), total IgE, and specific IgEs were studied before and 3, 6, 12 months after OLT. Six patients (21%) developed multiple food allergies. Mean age of six patients at OLT who developed food allergy was younger compared to the non-food allergy group (10.2 months vs. 68.9 months, p < 0.05). Food allergy has been developed within 1 yr in 5, and in 20 months in one patient after OLT. All six patients had cow's milk and egg allergy after OLT. Five children developed wheat, one children developed lentil and another one developed peach allergy in addition to cow's milk and egg allergy. Out of six food-allergic patients after OLT, four children developed Epstein-Barr virus (EBV) infection prior to food allergy. Before OLT, TECs and total IgE levels were not differed among food allergic and non-food allergic patients (p > 0.05). Mean of TECs were significantly higher in food allergic group compared to non-food allergic group at each time point after OLT (p < 0.05). Though statistically insignificant, mean of total IgE levels were also higher in the food allergic group (p > 0.05). These findings suggest that food allergy should be considered after OLT in patients who are younger than 1 yr of age, who developed hypereosinophilia, high total IgE levels or EBV viremia.

New-onset post-transplantation food allergy in children--is it attributable only to the immunosuppressive protocol?

New-onset post-transplantation food allergy has been described mainly after liver transplantation, and its pathogenesis was attributed to the immunomodulatory effects of tacrolimus therapy. The aim of the present study was to evaluate the association of food allergy with solid organ transplantation in our center. The medical records of children who underwent kidney transplantation and children who underwent liver or liver and kidney transplantation from 1986 to 2005 were reviewed. A total of 189 children (124 after kidney transplantation, 65 after liver or liver and kidney transplantation) received tacrolimus as part of the immunosuppressive regimen. New-onset post-transplantation food allergy was documented in four of them: two with liver transplants and two with combined kidney and liver transplants. The absence of new-onset food allergy in the children with isolated kidney transplants is compatible with other reports in the literature. This study supports the concept that the functioning liver itself, and not only tacrolimus immunosuppression, is a main contributor to food allergy in this patient population.

Cyclosporin A Treatment Is Associated with Increased Serum Immunoglobulin E Levels in a Subgroup of Atopic Dermatitis Patients

Cyclosporin A is increasingly used in the treatment of severe refractory atopic dermatitis. Although cyclosporin A treatment is highly efficacious and relatively safe, we report four adult atopic dermatitis (AD) patients who deteriorated during long-term cyclosporin A treatment, with clinical signs and symptoms more severe than at the onset of treatment. Interestingly, these patients showed large increases of total serum immunoglobulin E (IgE) levels, paralleled by increasing disease severity and serum levels of thymus and activation-regulated chemokine. This implies that cyclosporin A may induce a shift to Th2, resulting in increased IgE synthesis, in a subpopulation of AD patients. We therefore suggest that in this subpopulation, treatment with anti-B cell or combined anti-B and T-cell treatment may be favorable.

The development of eosinophilic colitis after liver transplantation in children

Tacrolimus-based immunosuppression in pediatric liver transplant recipients is known to be associated with EGID. Our goal was to determine the incidence, risk factors, and characteristics of EGID in our pediatric liver transplantation program. This study was a retrospective analysis of 38 pediatric liver transplant recipients. Rectal mucosal biopsy was performed to evaluate for gastrointestinal PTLD and eosinophilic colitis. There were 14 patients (37%) who were diagnosed with eosinophilic colitis. The mean age at transplantation was 10.8 +/- 1.8 months. Those with eosinophilic colitis had a higher incidence of peripheral eosinophilia (p = 0.003) during the first two months following transplantation and had a higher EBV infection rate. Symptoms, such as diarrhea, hematochezia, and abdominal pain, became apparent after an average of three months; diagnoses were made at 6.9 +/- 2.0 months after transplantation. There were eight patients (57%) with elevated food-specific IgE levels. With food restriction treatment, the symptoms of patients improved. EGID should be considered when clinical symptoms are present, because symptoms of this disorder are similar to those of gastrointestinal PTLD. It should also be considered when peripheral eosinophila is detected or when EBV seroconversion develops during the first two months following transplantation.

Efficacy and safety of long-term treatment with cyclosporin A for atopic dermatitis

BACKGROUND

Cyclosporin A (CsA) is being increasingly used in the treatment of severe refractory atopic dermatitis. Clinical efficacy and safety of short-term cyclosporin A treatment in atopic dermatitis patients has been proven, however, data on long-term treatment are limited.

OBJECTIVE

The aim of this study was to investigate the efficacy, safety and the effect of discontinuation of cyclosporin A treatment in atopic dermatitis patients, with a particular focus on patients treated with cyclosporin A for more than 6 months.

METHODS

We performed a retrospective study of clinical and adverse effects of cyclosporin A treatment in 73 atopic dermatitis patients, with an average duration of cyclosporin A treatment of 1.3 years.

RESULTS

We included 73 patients (31 women and 42 men, with a mean age of 33.8 years) with severe atopic dermatitis refractory to conventional therapy that was treated with cyclosporin A. Treatment was successful in 56/73 patients. Increases in serum creatinine levels > 30% compared to baseline were reported in 7/73 patients. Arterial hypertension appeared in 11/73 patients during treatment. After discontinuation of treatment, 40/73 patients experienced a relapse and 33/73 patients experienced clinical remission for at least 3 months. No correlation between treatment duration and nephrotoxicity or hypertension was found. Strikingly, 6/73 patients experienced a rebound phenomenon.

CONCLUSIONS

We conclude that CsA is an effective and safe treatment for patients with severe AD refractory to conventional treatment, provided that the recommended guidelines for its administration are strictly observed. However, in contrast to previous reports, we found that 8% (6/73) of patients experienced a rebound phenomenon after discontinuation of treatment.

Tacrolimus-associated eosinophilic gastroenterocolitis in pediatric liver transplant recipients: role of potential food allergies in pathogenesis

Tacrolimus is a macrolide agent that is now the primary immunosuppressant used in prevention of graft rejection in transplant recipients. It has been found to be superior to cyclosporine (CSA) for rescue therapy as well as for earlier weaning of steroids. Both tacrolimus and CSA share similar toxicity profiles; however, their gastrointestinal side effects have received little attention. We report three cases of eosinophilic colitis in liver transplant recipients, maintained on tacrolimus as immunosuppressive medication post-liver transplantation. These patients also had high serum immunoglobulin (Ig)E levels, eosinophilia and IgE-positive radioallergosorbent test for milk proteins. The colitis appeared to be mediated by food allergies. Each patient had symptomatic improvement following reduced immunosuppression and an appropriately restricted diet. We conclude that tacrolimus may play a role in the initiation of food allergies, leading to eosinophilic colitis. More studies are needed in a controlled setting to identify the prevalence of similar findings among other pediatric liver transplant recipients.

Immunosuppressive therapy does not prevent the occurrence of immunoglobulin E-mediated allergies in children and adolescents with organ transplants

BACKGROUND

Allogeneic organ transplantation has become a common procedure in acute and chronic organ failure. The major limitation, rejection of the allograft by the host's immune system, can be limited by various immunosuppressive drugs that target the adaptive T-cell response. Most of these drugs are used in the treatment of allergic diseases as well, suggesting that transplant recipients under long-term immunosuppressive therapy should not develop any sensitizations or at least not show any clinical signs of allergy. Surprisingly, organ-transplanted children and adults do report symptoms of type 1 allergies, such as allergic rhinoconjunctivitis, bronchial asthma, and food allergies. Thus far, mainly case reports and series on the occurrence of allergy after orthotopic liver transplantation exist.

OBJECTIVE

Our purpose with this study was to evaluate in a cross-sectional design the prevalence of immunoglobulin E-mediated sensitizations and type 1 allergies in solid organ-transplanted children and adolescents and to identify risk factors.

METHODS

Seventy-eight organ-transplanted subjects (50 kidney, 9 lung, 19 liver; mean age: 14.06 +/- 5.94 years; range 1.42 to 24.25 years) were studied by standardized interviews (modified International Study of Asthma and Allergies in Childhood [ISAAC] criteria), skin-prick tests, and measurement of specific and total serum immunoglobulin E.

RESULTS

Nineteen patients (24.4%) were found to be sensitized to > or = 1 common inhalant or food allergens, as reflected by elevated specific immunoglobulin E levels and/or positive skin-prick test results, and 8 subjects (10.3%) additionally reported a corresponding present history of atopic diseases. No severe anaphylactic reactions were reported. No statistically significant associations with gender, kind of transplanted organ, distinct immunosuppressive therapies, and age at time of transplantation or age at investigation were found (chi2 test, Fisher's exact test, and Wilcoxon rank-sum test, respectively). Multiple logistic-regression analysis did not identify any independent risk factor either.

CONCLUSION

This study demonstrates that therapeutic immunosuppression does not control sensitizations and clinical manifestation of type 1 allergies in organ-transplanted children and adolescents.

Development of multiple food allergies in children taking tacrolimus after heart and liver transplantation

Angioedema and chronic diarrhea in patients taking immunosuppressants are not always because of side effects and could be a new onset of food allergy. Our aim is to discuss the pathogenesis and treatment of the post-transplant development of food allergies. The first patient was receiving tacrolimus subsequent to heart transplantation and developed angioedema after consumption of dairy products at 12 months after transplantation. He was found to be allergic to multiple foods by both RAST and ImmunoCAP tests. The second patient with argininosuccinic aciduria, post-liver transplant, also received tacrolimus and developed chronic non-mucoid/bloody diarrhea at seven months following transplantation. ImmunoCAP test was positive only for egg white and peanuts. Biopsy showed eosinophilic infiltration of the mucosa from the stomach to the rectum. Elimination diets in both patients resolved the symptoms. These cases suggest a direct relationship between tacrolimus and development of food allergy.

Calcineurin Inhibitors: A Novel Approach to Canine Atopic Dermatitis

The introduction of calcineurin inhibitors represents a major addition to the armamentarium of drugs available to veterinary clinicians for the management of allergic skin diseases. Both cyclosporine and tacrolimus have been proven to be well tolerated and effective for the treatment of atopic dermatitis in dogs. Although broad spectrum in their mechanism of action, they lack the major adverse effects of glucocorticoids and provide an appealing alternative to traditional therapies. The purposes of this article are to review clinically relevant information regarding these agents and to provide tips for maximizing the benefit obtained from these therapies.

Allergic disease after pediatric liver transplantation with systemic tacrolimus and cyclosporine a therapy

Cyclosporine A (CsA) and tacrolimus (Tac), both calcineurin inhibitors, have been used extensively for immunosuppressive therapy in pediatric liver transplant recipients. They share a similar mechanism of action, the inhibition of cytokine gene transcription primarily interleukin-2 (IL-2) in T lymphocytes. Despite the strong immunosuppressive property, there are several reports of food allergy in pediatric transplant recipients under Tac immunosuppression, but not CsA. In this paper we report on 3 of 50 pediatric liver transplant recipients diagnosed with food allergy and asthma while receiving systemic Tac/CsA immunosuppression and the discuss the role of calcineurin inhibitors in this situation.

Investigation on the effects of topical therapy with 0.1% tacrolimus ointment (ProtopicR) on intradermal skin test reactivity in atopic dogs

Tacrolimus ointment (TAC) is an effective treatment for atopic dermatitis in humans and dogs. The purposes of the present study were to evaluate the effect of 4 weeks of TAC on intradermal skin testing (IST), and in case of suppression, to investigate if reactivity returned to baseline by 2 or 4 weeks post treatment. Intradermal skin test was performed using saline, histamine, lipopolysaccharide (LPS, 0.4 mg mL(-1)), house dust (25 PNU mL(-1)) and house dust mite (1 : 40 000 w/v) at weeks 0, 4, 6 and 8 on nine dogs enrolled in a blinded, crossover, clinical trial, using 0.1% TAC or placebo once daily for 4 weeks. Reactions were evaluated at 15 min, and at 4 and 6 h. Ointment was applied after the 15-min evaluation on weeks 0 and 4. Data were analysed using the statistical software SAS System for Windows. At week 4, TAC did not affect 15-min IST, but some reactions in the TAC group were suppressed at 6 h compared to baseline. In the TAC group, 4-h IST reactivity was reduced 2 weeks after discontinuation but returned to baseline by 4 weeks. In conclusion, TAC has no effect on immediate reactions but decreased some late-phase reactions. Therefore, no withdrawal is recommended to evaluate only immediate reactions, but a 4-week withdrawal may be necessary for evaluation of late-phase reactions.

The potential role of allergen-specific sublingual immunotherapy in atopic dermatitis

Atopic dermatitis is a chronic inflammatory skin disease associated with increasing prevalence, morbidity, and cost in developed Western countries. Frequently associated with respiratory allergy during adulthood, atopic dermatitis often represents the first phenotypic appearance of atopy in early childhood when the allergic 'march' starts and progressively moves toward food allergy, asthma, and rhinitis. At present, a consistent body of evidence supports the view that atopic dermatitis may represent the skin compartmentalization of a systemic allergic inflammation. Lymphocytes infiltrating early lesional skin express a T helper (Th) 2 pattern of cytokine secretion (increased levels of interleukin [IL]-4 and/or IL-13 and decreased levels of interferon-gamma) as well as the typical Th2-type chemokine receptor CCR4, specific to the thymus and activation-regulated chemokines. Keratinocytes from patients with atopic dermatitis produce thymic stromal lymphopoietin, a novel cytokine that supports the early lymphocyte development in mouse models, and activates dendritic cells involved in the pathogenesis of allergic diseases in humans. Increased levels of circulating hemopoietic precursor cells have been reported in atopic dermatitis, as in allergic asthma and rhinitis. Furthermore, the recognition of CD34+ hemopoietic precursor cells, and evidence for cellular differentiation/maturational events occurring within atopic dermatitis skin lesion infiltrates, are consistent with the recent reinterpretation of the Th2/Th1 paradigm, where Th2 cells appear to belong to the early stages and Th1 to the ultimate stages of a linear, rather than divergent, pattern of lymphoid differentiation. This more detailed understanding of the immunologic derangements contributing to the atopic dermatitis pathogenesis has led to growing interest in allergen-specific immunotherapy for the disease. Due to the complexity intrinsic to atopic dermatitis and the lack of consensus-based guidelines for standardized outcome measure, only eight studies are available in the literature for a qualitative evaluation of this treatment approach. Two of these studies were double blind and placebo controlled, and six were cohort studies. Immunotherapy was found to be effective in one controlled study and five observational reports. Uncertain results were provided by one low-powered, controlled study, and negative outcomes were raised by a unique study performed with oral immunotherapy, which is not an effective route of mucosal allergen administration. Thus, more efficacy studies are required before immunotherapy could be recommended for the routine treatment of atopic dermatitis. Allergen-specific sublingual immunotherapy, given its excellent safety profile and ability to interfere with the systemic aspects of allergic inflammation, appears a good potential candidate for the pathogenetic treatment of the disease.

Manifestations and linkage analysis in X-linked autoimmunity-immunodeficiency syndrome

The clinical findings of a kindred with an X-linked disorder are characterized by autoimmune polyendocrinopathy, enteropathy with villous atrophy, chronic dermatitis, and variable immunodeficiency. Linkage analysis was performed on 20 members of the affected kindred to determine the location of the responsible locus. Informative recombinations limited the region to an approximate 20 cM interval bordered by DXS1055 and DXS1196/DXS1050. Multipoint analysis generated a lod score >3 for the region contained between DXS8024 and DXS8031. The candidate region includes the Wiskott-Aldrich syndrome (WAS) locus. Evaluation of the Wiskott-Aldrich syndrome protein gene by single strand conformational analysis, heteroduplex analysis, and direct sequencing of the 12 exons in an affected male and two carrier females revealed no abnormalities. We conclude that this kindred has an X-linked disorder, distinct from WAS, that results in autoimmunity and variable immunodeficiency. The responsible locus maps to the pericentromeric region Xp11.23 to Xq21.1.

In Vivo Kinetics of Transduced Cells in Peripheral T Cell-Directed Gene Therapy: Role of CD8+ Cells in Improved Immunological Function in an Adenosine Deaminase (ADA)−SCID Patient

We previously reported successful peripheral T cell-directed gene therapy in a boy with adenosine deaminase (ADA)−SCID. In the present study, to better understand the reconstitutive effect of this gene therapy on his immunological system, we investigated the in vivo kinetics and functional subsets of T cells in PBL. Apparent immunological improvements were obtained after infusion of transduced cells at more than 4 × 108 cells/kg/therapy/3 mo. Frequency of ADAcDNA-integrated cells in PBL, ADA activity in PBL and clinical improvement showed good correlation, even though CD8+ cells gradually became predominant in PBL. On the basis that polyethylene glycol (PEG)-ADA was maintained at the same dosage as before gene therapy, we consider that his immunological improvement resulted from the gene therapy itself. Most CD3+ cells in PBL after gene therapy expressed TCRαβ. Analysis of TCR repertoire based on TCR V region usage revealed no expansion of limited clones in his PBL. The T cell subset cells CD8+CDw60+ and CD8+CD27+CD45RA−, which are reported to provide substantial help to B cells, were maintained throughout the gene therapy. Furthermore, his reconstituted peripheral T cells helped normal B cells to produce substantial IgG in vitro. Expression of both Th1- and Th2-type cytokine genes was induced in his reconstituted T cells at the same comparably high level as in normal subjects. Collectively, these results provide evidence of persistent and distinct functions of transduced cells in this patient’s PBL after gene therapy.

Elevation of serum IgE level and peripheral eosinophil count during T lymphocyte-directed gene therapy for ADA deficiency: implication of Tc2-like cells after gene transduction procedure

We have successfully carried out T-cell-directed gene therapy for a boy with severe combined immunodeficiency due to adenosine deaminase deficiency (ADA SCID) and unexpectedly found an elevation of serum IgE level and peripheral eosinophil count during the course. More than 90% of transduced cells cultured for 7-11 days before infusion into the patient were positive for CD8 and expressed Th2-type cytokine genes such as IL-4, IL-5 and IL-13. Furthermore, CD4(+) T-depleted PBMC (peripheral blood mononuclear cells) from the patient synthesized IgE in vitro by stimulation with IL-4. Collectively, these results suggested that Tc2-like cells in the transduced cells have distinct immunological functions to help IgE synthesis and activate eosinophils.