Benjamin Gesundheit

Immunological and autoimmune considerations of Autism Spectrum Disorders

Autism Spectrum Disorders (ASD) are a group of heterogeneous neurodevelopmental conditions presenting in early childhood with a prevalence ranging from 0.7% to 2.64%. Social interaction and communication skills are impaired and children often present with unusual repetitive behavior. The condition persists for life with major implications for the individual, the family and the entire health care system. While the etiology of ASD remains unknown, various clues suggest a possible association with altered immune responses and ASD. Inflammation in the brain and CNS has been reported by several groups with notable microglia activation and increased cytokine production in postmortem brain specimens of young and old individuals with ASD. Moreover several laboratories have isolated distinctive brain and CNS reactive antibodies from individuals with ASD. Large population based epidemiological studies have established a correlation between ASD and a family history of autoimmune diseases, associations with MHC complex haplotypes, and abnormal levels of various inflammatory cytokines and immunological markers in the blood. In addition, there is evidence that antibodies that are only present in some mothers of children with ASD bind to fetal brain proteins and may be a marker or risk factor for ASD. Studies involving the injection of these ASD specific maternal serum antibodies into pregnant mice during gestation, or gestational exposure of Rhesus monkeys to IgG subclass of these antibodies, have consistently elicited behavioral changes in offspring that have relevance to ASD. We will summarize the various types of studies associating ASD with the immune system, critically evaluate the quality of these studies, and attempt to integrate them in a way that clarifies the areas of immune and autoimmune phenomena in ASD research that will be important indicators for future research.

Allogeneic stem cell transplantation for severe acquired aplastic anaemia using a fludarabine-based preparative regimen.

We reviewed our experience in the treatment of 13 patients with severe acquired aplastic anaemia, using a newly developed non‐myeloablative regimen consisting of fludarabine (total dose 180 mg/m2), cyclophosphamide (total dose 120 mg/kg), and antithymocyte globulin (total dose 40 mg/kg). All except one patient received multiple transfusions and had failed prior immunosuppressive treatment. Twelve out of 13 patients achieved sustained engraftment. One patient was not evaluable for engraftment because of early death on day +10. None of the patients developed graft failure. Mucositis of mild‐to‐moderate severity was the only observed regimen‐related toxicity. The cumulative incidence of acute graft‐versus‐host disease (GvHD) grade II–IV and III–IV was 8·3% and 0%, respectively. With a median follow‐up period of 45 months, the 5‐year overall survival probability was 84%. Eight out of 11 surviving patients have been followed for more than 1 year and only one developed limited chronic GvHD. All patients enjoy a normal life style, with a Karnofsky score of 100%, and all except three, followed for 3, 5 and 6 months respectively, are free of any immunosuppressive medication. The results of this study look promising, while prospective clinical trials may be required to confirm the benefits of this regimen as an alternative to existing protocols.

Sparing effect by montelukast treatment for chronic graft versus host disease: a pilot study.

Background. Chronic graft versus host disease (GvHD) is a major complication after allogeneic stem cell transplantation (SCT), which is usually progression from acute GvHD. Chronic GvHD is the main cause of severe morbidity and mortality in long-term survivors after SCT. The cysteinyl leukotrienes (cysLTs) and eosinophils play an important role in the pathogenesis of GvHD, which is the rationale for the combined use of montelukast (Mk) in the treatment of this illness. Methods. Mk was administrated to 19 eligible patients with refractory chronic GvHD, in addition to their standard immunosuppressive regimens. Mk was given orally (10 mg once daily) for a mean period of 10 months (range, 2–21 months). Organ-specific response was determined by the new scoring criteria established by the National Institutes of Health consensus project. Results. Based on organ involvements endpoints, overall response to the combined therapy with Mk was observed in 15 of 19 (79%) patients. Significant improvement of skin liver and gastrointestinal was observed in 53%, 62%, and 46%, respectively. Generally, Mk was notably beneficial in milder stages of GvHD, which lead to earlier withdrawal of other immunosuppressive agents. Side effects of Mk administration were not documented, nor were cases of relapse of the basic disease. Conclusions. Our preliminary prospective investigation supports the potential efficacy of Mk as a safe and toxicity-sparing supplement to standard therapy for patients with chronic GvHD. Future clinical studies are necessary to establish the optimal dose of Mk and its role in the symptomatic and prophylactic treatment of acute and chronic GvHD.

Treatment of post-hematopoietic stem cell transplantation hemorrhagic cystitis with intravesicular sodium hyaluronate

Hemorrhagic cystitis (HC) is a well-known complication of HSCT. Its overall incidence has been reported to vary from 7–68%. The spectrum of clinical presentation varies from asymptomatic microhematuria to life-threatening bleeding. Sodium hyaluronate is a glycosaminoglycan present on the bladder mucosa, which serves as an important protective substance against uroepithelial damage. Preparations of this component have been shown to be effective in the treatment of interstitial cystitis. We report our experience in the treatment of post-transplant HC with intravesical instillation of sodium hyaluronate. Five out of the seven patients included in this study achieved complete response, while one patient had only partial response. Sodium hyaluronate administration was not associated with any local or systemic adverse effects. We consider that the results of our study are promising and the efficacy of sodium hyaluronate in the treatment of post-transplant HC should be tested in larger cohorts of patients.

Rapid response to alefacept given to patients with steroid resistant or steroid dependent acute graft-versus-host disease: a preliminary report.

Summary:We evaluated the effect of alefacept (Amevive), a novel dimeric fusion protein, in steroid resistant/dependent acute graft-versus-host-disease (aGVHD). Seven patients were treated in eight aGVHD episodes. GVHD grade at treatment initiation and at peak ranged 2–4 (median 2.5) and 2–4 (median 4), respectively. System involvement at GVHD peak included skin (n=7), gastrointestinal tract (n=5) and liver (n=3). All patients responded. However, one patient with skin GVHD and two with gastrointestinal GVHD featuring an early initial response (IR) exacerbated and CR was not achieved. Skin GVHD responded rapidly with a median of 1 day to IR and 7 days to CR. Intestinal response was slower with median 7.5 days to IR. Of the four patients that achieved IR, CR was achieved in only one (40 days to CR). None of the patients had significant hepatic GVHD before treatment so no hepatic effect of alefacept could be determined. No immediate alefacept-related side effects were observed. Late side effects included infections (aspergillus sinusitis, pneumonia, bacteremia, pharyngeal thrush), pancytopenia and hemorrhagic cystitis. Three patients had CMV reactivation while on alefacept. We conclude that alefacept may have a beneficial effect in controlling aGVHD. Further investigations in larger cohorts of patients and controlled studies are warranted.

A retrospective review of the outcome after second or subsequent allogeneic transplantation.

The failure of allogeneic stem cell transplant (allo-SCT) is cumbersome. We analyzed our experience in a second allo-SCT. Between the years 1981 and 2007, 144 patients underwent 2 or more allo-SCT. The first to second transplant interval ranged from 18 days to 13.25 years (median 98 days). The most frequent indications for the second SCT were activity of the basic disease (78), rejection (37), and engraftment failure (25). Twenty-nine of the 144 (20%) patients transplanted survived more then a year with treatment-related mortality of 45.5% as the leading cause of death. Interestingly, despite the low rate of graft-versus-host disease (GVHD) prophylaxis used, only 51 and 16 of the patients developed acute and chronic GVHD (aGVHD, cGVHD), respectively. Factors indicating higher likelihood for survival were nonmalignant disease, a nonrelapse indication for the second SCT, full HLA-matching, and the use of reduced-intensity conditioning (RIC). Age at transplantation, time interval between transplants, the development of GVHD, conditioning regimen, GVHD prophylaxis, or graft source were not shown to influence the prognosis. With a median follow-up of 4.5 years, 25 patients (17.2%) are alive, and 18 are disease-free. We conclude that although toxic, a second allo-SCT can lead to long-term survival.

Alefacept treatment for refractory chronic extensive GVHD

Alefacept (Amevive) is an immunosuppressive dimeric fusion protein that is used for psoriasis control. We recently showed its effect in acute steroid-resistant/dependent GVHD. In this study, we describe the effect of alefacept treatment on chronic extensive GVHD (cGVHD). Twelve patients were included in this study; of these 8 (9 of 13 episodes) showed response. The median time to initial response was 2.25 weeks and the response was marked (n=3), moderate (n=2) or minimal (n=4). In two responding patients, the response was only temporary. Complications that appeared during treatment included infection, pericarditis and squamous cell carcinoma of the lip. All these events may be related to other drugs given simultaneously. With a 30-month median follow-up, 6 of 12 patients are alive, with all but one with stable or improved cGVHD. Six patients died because of GVHD progression, whereas none of the patients experienced relapse of the disease for which the transplantation was done. As reported earlier in psoriatic patients treated with alefacept, we found a consistent increase in the percentage of naive T cells as a consequence of treatment. In conclusion, alefacept is effective for the treatment of cGVHD, and dose and time intervals of treatment should be explored further.

A prospective, double-blind phase II study evaluating the safety and efficacy of a topical histamine gel for the prophylaxis of oral mucositis in patients post hematopoietic stem cell transplantation.

The aim of this study was to evaluate the safety, tolerability and efficacy of a topical gel containing histamine dihydrochloride (HDC) versus a placebo gel in preventing oral mucositis in hematopoietic stem cell transplantation (HSCT) patients. A total of 45 patients post-HSCT were enrolled in a prospective longitudinal, placebo-controlled, double-blind study. Patients were evaluated twice weekly for oral mucositis (OMAS, NCI score), oral pain (VAS), oral function and salivary flow rate. Compliance was assessed using a patient diary. Oral mucositis developed in 85% of the HDC group and 63% of the placebo group. The mean maximal intensity for NCI score was 1.45±1 in the HDC group and 1.21±1.27 in the placebo group (P=0.37). The mean duration of oral mucositis was 4.7±3.6 and 2.33±2.23 days in the HDC and placebo groups, respectively (P=0.06). The same trends were measured with OMAS. Visual analogue scale for oral pain and oral function was not significantly different between the two groups. Histamine dihydrochloride was found to be safe. In the search for topical agents for the prevention of mucositis, we found that HDC neither improves nor worsens oral mucositis in HSCT patients. The balance between the pro- and anti-inflammatory effects of HDC should be investigated further in order to acquire a clinically effective topical medication based on its anti-inflammatory properties.

Cyclosporin A in the treatment of refractory immune thrombocytopenia purpura in children

Abstract: Patients with refractory autoimmune thrombocytopenia do not respond to standard therapy with high‐dose corticosteroids, intravenous immunoglobulin, and splenectomy. We describe the cases of two patients with refractory autoimmune thrombocytopenia treated with oral cyclosporin A (CsA) to evaluate the efficacy of this alternative therapy. Blood pressure and hepatic and renal function were in the normal range before initiation of treatment. Induction therapy with pulses of high‐dose methylprednisolone was used for 3 consecutive days to improve the initial immune suppression. Gradual dose reduction of CsA, according the platelet count, minimized the long‐term adverse effects of CsA. Oral CsA with pulses of high‐dose methylprednisolone induced remission of the thrombocytopenia. Gradual weaning of CsA over months, according the platelet count, produced no observable adverse effects of the CsA. Rapid dose reduction caused thrombocytopenia, which resolved with higher dosages of CsA. Our cases show the efficacy of CsA for refractory immune thrombocytopenia. This therapeutic option with oral CsA as an additional salvage option may avoid splenectomy and the adverse effects of long‐term corticosteroids. Larger clinical investigations are necessary to establish the indications and therapeutic regimen for CsA in immune thrombocytopenia.

Variation in Gene Expression in Autism Spectrum Disorders: An Extensive Review of Transcriptomic Studies

Autism spectrum disorders (ASDs) are a group of complex neurodevelopmental conditions that present in early childhood and have a current estimated prevalence of about 1 in 68 US children, 1 in 42 boys. ASDs are heterogeneous, and arise from epigenetic, genetic and environmental origins, yet, the exact etiology of ASDs still remains unknown. Individuals with ASDs are characterized by having deficits in social interaction, impaired communication and a range of stereotyped and repetitive behaviors. Currently, a diagnosis of ASD is based solely on behavioral assessments and phenotype. Hundreds of diverse ASD susceptibility genes have been identified, yet none of the mutations found account for more than a small subset of autism cases. Therefore, a genetic diagnosis is not yet possible for the majority of the ASD population. The susceptibility genes that have been identified are involved in a wide and varied range of biological functions. Since the genetics of ASDs is so diverse, information on genome function as provided by transcriptomic data is essential to further our understanding. Gene expression studies have been extremely useful in comparing groups of individuals with ASD and control samples in order to measure which genes (or group of genes) are dysregulated in the ASD group. Transcriptomic studies are essential as a key link between measuring protein levels and analyzing genetic information. This review of recent autism gene expression studies highlights genes that are expressed in the brain, immune system, and processes such as cell metabolism and embryology. Various biological processes have been shown to be implicated with ASD individuals as well as differences in gene expression levels between different types of biological tissues. Some studies use gene expression to attempt to separate autism into different subtypes. An updated list of genes shown to be significantly dysregulated in individuals with autism from all recent ASD expression studies will help further research isolate any patterns useful for diagnosis or understanding the mechanisms involved. The functional relevance of transcriptomic studies as a method of classifying and diagnosing ASD cannot be underestimated despite the possible limitations of transcriptomic studies.