Multiple doses of secretin in the treatment of autism: a controlled study

Dramatic effects on autistic behaviour after repeated injections of the gastrointestinal hormone secretin have been referred in a number of case reports. In the absence of curative and effective treatments for this disabling condition, this information has created new hope among parents. Although controlled studies on the effect of mainly one single dose have not documented any effect, many children still continue to receive secretin. Six children enrolled in a double-blind, placebo-controlled crossover study in which each child was its own control. Human synthetic secretin, mean dose 3.4 clinical units, and placebo were administered intravenously in randomized order every 4th wk, on three occasions each. The measurement instruments were the visual analogue scale (VAS) and the aberrant behaviour checklist (ABC). Statistically significant differences were found for placebo in 3 out of 6 children and for secretin in one child, using parental ratings only (VAS scores). Differences were small and lacked clinical significance, which was in accordance with the overall impression of the parents and teachers and visual inspection of graphs.

CONCLUSION

In this placebo-controlled study, multiple doses of secretin did not produce any symptomatic improvement.

RG-1068 RepliGen

RG-1068 is a synthetic form of the natural human hormone secretin under development by RepliGen for the potential treatment of autism. RG-1068 received Fast Track designation for the treatment of pediatric autism in September 2001, and in February 2002, it entered phase III clinical trials.

Autism, an extreme challenge to integrative medicine. Part 2: medical management

Autism and allied autistic spectrum disorders (ASD) present myriad behavioral, clinical, and biochemical abnormalities. Parental participation, advanced testing protocols, and eclectic treatment strategies have driven progress toward cure. Behavioral modification and structured education are beneficial but insufficient. Dietary restrictions, including removal of milk and other casein dairy products, wheat and other gluten sources, sugar, chocolate, preservatives, and food coloring are beneficial and prerequisite to benefit from other interventions. Individualized IgG or IgE testing can identify other troublesome foods but not non-immune mediated food sensitivities. Gastrointestinal improvement rests on controlling Candida and other parasites, and using probiotic bacteria and nutrients to correct dysbiosis and decrease gut permeability. Detoxification of mercury and other heavy metals by DMSA/DMPS chelation can have marked benefit. Documented sulfoxidation-sulfation inadequacies call for sulfur-sulfhydryl repletion and other liver p450 support. Many nutrient supplements are beneficial and well tolerated, including dimethylglycine (DMG) and a combination of pyridoxine (vitamin B6) and magnesium, both of which benefit roughly half of ASD cases. Vitamins A, B3, C, and folic acid; the minerals calcium and zinc; cod liver oil; and digestive enzymes, all offer benefit. Secretin, a triggering factor for digestion, is presently under investigation. Immune therapies (pentoxifyllin, intravenous immunoglobulin, transfer factor, and colostrum) benefit selected cases. Long-chain omega-3 fatty acids offer great promise. Current pharmaceuticals fail to benefit the primary symptoms and can have marked adverse effects. Individualized, in-depth clinical and laboratory assessments and integrative parent-physician-scientist cooperation are the keys to successful ASD management.

Lack of benefit of intravenous synthetic human secretin in the treatment of autism

The objective of this study was to determine if an intravenous infusion of synthetic human secretin improves language and behavioral symptoms in children with autism. Forty-two children with the diagnosis of autism were randomized to one of two groups in this double-blind cross-over trial. One group received 2 IU/kg of intravenous synthetic human secretin at the first visit, followed by an equal volume of intravenous saline placebo at week 6. The other group received treatments in the reverse order. All children were evaluated at weeks 1, 3, 6, 9, and 12 with standardized assessments of language, behavior, and autism symptomatology. There were no significant differences in the mean scores on any measure of language, behavior, or autism symptom severity after treatment with secretin compared to treatment with placebo. The results of this study do not support secretin as a treatment for autism.

A randomized, double-blind, placebo-controlled trial of porcine versus synthetic secretin for reducing symptoms of autism

OBJECTIVE

To compare the effects of a single dose of biologic and synthetic porcine secretin to placebo on a variety of autism symptoms.

METHOD

Eighty-five children with autism without other medical conditions and not taking other psychotropic medications participated (ages between 3 and 12 years, mean IQ = 55). Children were grouped into trios matched by age and communication level and then randomly assigned to one of three treatment groups: biologic secretin (2 CU/kg), synthetic secretin (0.4 microg/kg), and placebo. Measures collected 1 week before and 4 weeks after infusion included autism symptoms, language skills, and problem behaviors, gathered from parents, teachers, and investigators, who were all blind to treatment. Two-factor, repeated-measures analyses of variance (3 treatment levels by 2 repeated measures, pre- and postinfusion) were used to examine efficacy.

RESULTS

Direct observation measures did not show change over time related to secretin. Parent reports showed an overall reduction of symptom severity for all treatment groups, including the placebo group. One teacher-report measure showed decreases in autism symptoms in the placebo and synthetic secretin groups.

CONCLUSIONS

No evidence that either biologic or synthetic secretin provided amelioration of symptoms beyond placebo was observed. This held true when children with and without gastrointestinal problems were examined separately.

Facilitation of pancreatic duct cannulation using a new synthetic porcine secretin

OBJECTIVES

Cannulation of the pancreatic duct at ERCP can represent a technical challenge, even to experienced pancreaticobiliary endoscopists. Secretin is a polypeptide hormone that increases the volume and bicarbonate content of pancreatic secretions. We report our single center experience in the use of a new synthetic porcine secretin (sPS) for the facilitation of cannulation of either the major or minor pancreatic orifice during ERCP.

METHODS

Patients presenting for a variety of indications were enrolled. If identification or cannulation of the desired pancreatic duct was difficult, 0.2 microg/kg of sPS was administered i.v. Cannulation success or failure was recorded.

RESULTS

Between March, 1999, and May, 2000, a total of 25 patients (seven men and 18 women) were enrolled. The most frequent indication (15 of 25 cases) was facilitation of dorsal pancreatic duct cannulation in patients with pancreas divisum. The overall rate of successful cannulation secretin administration was 24 of 25 cases (96%). No adverse events directly attributable to secretin were observed.

CONCLUSIONS

The results of this study show that sPS is safe and efficacious in faciliting cannulation of either the major or minor pancreatic orifice at ERCP in the subset of patients who represent cannulation difficulties. Once commercially available, sPS can be added to the armamentarium of techniques to facilitate ERP.

Secretin as a neuropeptide

The role of secretin as a classical hormone in the gastrointestinal system is well-established. The recent debate on the use of secretin as a potential therapeutic treatment for autistic patients urges a better understanding of the neuroactive functions of secretin. Indeed, there is an increasing body of evidence pointing to the direction that, in addition to other peptides in the secretin/glucagon superfamily, secretin is also a neuropeptide. The purpose of this review is to discuss the recent data for supporting the neurocrine roles of secretin in rodents. By in situ hybridization and immunostaining, secretin was found to be expressed in distinct neuronal populations within the cerebellum and cerebral cortex, whereas the receptor transcript was found throughout the brain. In the rat cerebellum, secretin functions as a retrograde messenger to facilitate GABA transmission, indicating that it can modulate motor and other functions. In summary, the recent data support strongly the neuropeptide role of secretin, although the secretin-autism link remains to be clarified in the future.

Secretin treatment for autistic disorder: a critical analysis

We assessed evidence of the effects of secretin on behavior in individuals with autistic disorder. Articles were obtained through a MEDLINE search of the English-language literature from January 1966-November 2001; all investigations and case reports on the topic were included. Press releases obtained from the World Wide Web also were included. Secretin, a gastrointestinal hormone, is suggested to improve autistic symptoms, particularly social function and communication. Two formulations, porcine and synthetic human secretin, were evaluated in humans. A small body of literature and popular belief in autistic disorder communities supported the agent's efficacy. A number of controlled clinical trials did not show improvement in autistic symptoms with secretin compared with placebo, possibly indicating no role for the drug in autistic disorder.

Efficacy of porcine secretin in children with autism and pervasive developmental disorder

Secretin, a gastrointestinal (GI) hormone, was reported in a preliminary study to improve language and behavior in children with autism/pervasive developmental disorder (PDD) and chronic diarrhea. To determine the efficacy of secretin, we completed a double-blind, placebo-controlled, crossover (3 weeks) study in children with autism/PDD and various GI conditions using a single dose of intravenous porcine secretin. Children with chronic, active diarrhea showed a reduction in aberrant behaviors when treated with the secretin but not when treated with the placebo. Children with no GI problems are unaffected by either secretin or placebo. The improvement seen with secretin in children with autism/PDD and chronic diarrhea suggests that there may be a subtype of children with autism/PDD who respond to secretin.

Double-blind placebo-controlled trial of secretin: effects on aberrant behavior in children with autism

Secretin has been proposed as a treatment alternative for autistic spectrum disorders, but empirical support is lacking. A double-blind placebo-controlled study examined the effect of a single dose of synthetic human secretin on aberrant behavior. Parent and teacher data from the Aberrant Behavior Checklist for eight male children were analyzed for reliable change in a clinical replication series. By parent and teacher report, the majority of change occurred either on the placebo trial or reflected deterioration subsequent to secretin infusion. Repeated-measures multivariate analysis of variance results were similar. Results are consistent with other studies, suggesting that secretin may not be an effective treatment option.

Biochemical aspects in autism spectrum disorders: updating the opioid-excess theory and presenting new opportunities for biomedical intervention

Autism is a lifelong condition usually described as affecting social, cognitive and imaginative abilities. For many years, parents and some professionals have observed that in concordance with the behavioural and psychological symptoms of the condition, there are a number of physiological and biochemical correlates which may also be of relevance to the syndrome. One area of interest that encompasses many of these observations is the opioid-excess theory of autism. The main premise of this theory is that autism is the result of a metabolic disorder. Peptides with opioid activity derived from dietary sources, in particular foods that contain gluten and casein, pass through an abnormally permeable intestinal membrane and enter the central nervous system (CNS) to exert an effect on neurotransmission, as well as producing other physiologically-based symptoms. Numerous parents and professionals worldwide have found that removal of these exogenously derived compounds through exclusion diets can produce some amelioration in autistic and related behaviours. There is a surprisingly long history of research accompanying these ideas. The aim of this paper is to review the accompanying evidence in support of this theory and present new directions of intervention as a result of it.

Secretin for the treatment of autism

OBJECTIVE

To evaluate the role of secretin in the treatment of children with autism.

DATA SOURCE

Literature was assessed through MEDLINE, EMBASE, BIOSIS (November 1998-August 2001), and the World Wide Web. Literature included scientific studies, anecdotal reports, and meeting abstracts. Key search terms included autism and secretin.

DATA SYNTHESIS

Autism is a pervasive developmental disorder. Although several treatments exist, no cure has been identified. New information suggests that secretin may be beneficial for this disorder. A critical evaluation of current information about the use of secretin in autism was conducted.

CONCLUSIONS

Currently, several anecdotal reports and a few controlled trials with conflicting results have been published regarding the use of secretin in autism. Further studies should be conducted to determine the safety and efficacy of secretin for autism.

Use of secretin in the treatment of childhood autism

The paper presents current views concerning childhood autism. The authors present the concepts of etiology of this disorder, emphasizing the role of negative psychical stimuli in early childhood and the role of mother's contact with the child. Organic factors, including genetic background, developmental abnormalities of the nervous system, teratogenic factors and perinatal traumas are also taken into consideration. The role of metabolic factors and enterohormones, particularly those belonging to the secretin group and their effect on the function of the gastrointestinal tract and central nervous system is emphasized. We discuss signs which may be indicative of first symptoms of autism in different age groups. A typical symptom of autism is no development of speech, observed from infancy, taking the form of complete mutism at later stages. It has been emphasized that most pathologic symptoms result from altered perception of external stimuli, which arouse fear and anxiety. Autistic patients may suffer from gastrointestinal tract disturbances such as abdominal pains and diarrhea. Methods used hitherto in the therapy of childhood autism, mainly by psychologists and psychiatrists, as well as some attempts of pharmacological treatment, are presented. The structure and function of secretin, as well as its effects on the motor and secretory function of the stomach and the exocrine function of the pancreas are discussed. The role of secretin in diagnostic tests, among others in the diagnosis of gastrinoma, is emphasized. We also present the history of the application of secretin in the therapy of childhood autism.

Secretin and sleep in children with autism

The objectives of this pilot study were 1) to examine possible effects of secretin infusions on sleep-wake state organization in children with autism, and 2) to assess the feasibility of home recordings using time-lapse videosomnography in children with autism. Participants were a subset of subjects from two double blind, placebo-control, multi-center clinical trials. One trial, the UC Irvine study, assessed the effects of porcine secretin vs. saline infusions on children's behavior, language and IQ. The UC Davis trial assessed the effects of synthetic human secretin vs. saline infusions on behavior, language and gastrointestinal function. The sleep study enrolled some of the children from each of the two trials to observe possible secretin effects on sleep. To examine sleep, the UC Irvine trial used the Children's Sleep Habits Questionnaire and daily sleep diaries, whereas the UC Davis study used home-recorded time-lapse videosomnography. Because of the small sample size, the results from both trials are preliminary. They suggest that secretin, porcine or synthetic, does not improve sleep-wake state organization dramatically.

Effects of intravenous secretin on language and behavior of children with autism and gastrointestinal symptoms: a single-blinded, open-label pilot study

BACKGROUND

Autism is a severe developmental disorder with poorly understood etiology. A recently published case series describes 3 autistic children with gastrointestinal symptoms who underwent endoscopy and intravenous administration of secretin and were subsequently noted by their parents to demonstrate improved language skills over a 5-week period. This report sparked tremendous public interest, and investigators at several sites moved quickly to design controlled trials to test the efficacy of secretin as a therapy for autistic children. However, this is the first effort specifically designed to replicate the initial reported findings in terms of patient age, presenting symptoms, and drug administration.

OBJECTIVE

To rigorously apply the scientific method by assessing the reproducibility of the reported effects of intravenous secretin on the language of young children with autism and gastrointestinal symptoms.

METHODS

We performed a single-blinded, prospective, open-label trial by conducting formal language testing and blinded behavioral rating both before and repeatedly after a standardized infusion of secretin. We selected autistic children who were similar in age and profile to those described in the published retrospective case review. Inclusion criteria for study participation included age (3-6 years), confirmed diagnosis of autism, and reported gastrointestinal symptoms (16 had chronic diarrhea, 2 had gastroesophageal reflux, and 2 had chronic constipation). Twenty children (18 male) were admitted to the Pediatric Clinical Research Center at the University of California, San Francisco after administration of the Preschool Language Scale-3 (PLS-3). A 3 CU/kg dose of secretin (Secretin-Ferring) was administered intravenously (upper endoscopy was not performed). Behavioral ratings were derived using the Autism Observation Scale applied to a 30-minute time sample of the child's behavior consisting of a videotape of the PLS-3 (structured setting) and a second free play session with a standard set of developmentally appropriate toys. Participants then returned for follow-up evaluations, with readministrations of the PLS-3 at 1, 2, 3, and 5 weeks' postinfusion, and videotaping of each session for later blinded review by 2 independent observers using the Autism Observation Scale, uninformed about week of posttreatment. We also surveyed parents of our study children about their impressions of the effects of secretin using a 5-point Likert scale for parents to rate changes seen in their child.

RESULTS

With a total study completion rate across all participants of 96%, repeated measures analyses of variance revealed no significant increases in children's language skills from baseline across all 5 study time periods after a single infusion of secretin. Similarly, neither significant decreases in atypical behaviors nor increases in prosocial behaviors and developmentally appropriate play skills emerged. Furthermore, no relationship was found between parental reports of change and observable improvement in the sample. Despite the objective lack of drug effect, 70% of parents in our study reported moderate to high change in their child's language and behavior. Furthermore, 85% of parents reported that they felt that their child would obtain at least some additional benefits from another infusion of secretin.

CONCLUSIONS

The results of our pilot study indicate that intravenous secretin had no effects in a 5-week period on the language and behavior of 20 children with autism and gastrointestinal symptoms. The open-label, prospective design of our study with blinded reviews of patients both before and after secretin administration follows the scientific method by seeking to reproduce an observed phenomenon using validating and reliable outcome measures. Pilot studies remain a mandatory step for the design of future randomized, clinical trials investigating potential treatments for children with autism.

A double-blind, placebo-controlled crossover study investigating the effect of porcine secretin in children with autism

A recent patient series reported the incidental findings of improved social and language skills in 3 children with autistic spectrum disorders after the administration of secretin, a peptide hormone. However, a subsequent study did not find evidence for a drug effect. Parents are seeking treatment with secretin despite the absence of empirical investigations demonstrating amelioration in autism symptomology. In order to more precisely measure the effects of secretin, this study investigated the effect of a single intravenous dose of porcine secretin on 12 autistic children through a randomized, double-blind, placebo-controlled, crossover study. Children were assessed on objective language and on social, neuropsychological, and gastrointestinal measures to evaluate drug effects. The study was conducted over a 16-week trial. The results indicated that significant differences were not observed on the majority of the dependent variables. Statistically significant differences were observed on measures of positive affect and activity level following secretin infusion. In general, the autistic children did not demonstrate the improvements described in the initial retrospective report.

Transdermal secretin for autism - a case report

Secretin hormone given daily in transdermal cream was associated with marked and sustained developmental progress in an aphasic two-and-a-half year old child diagnosed with autism.

A randomized controlled crossover study comparing synthetic porcine and human secretins with biologically derived porcine secretin to diagnose Zollinger-Ellison Syndrome

BACKGROUND

Although biologically-derived porcine secretin is approved for the diagnosis of Zollinger-Ellison Syndrome, it is no longer available in the United States. Pure human and porcine secretins have now been synthesized and new drug applications have been filed with the Federal Drug Administration (FDA).

METHODS

In the current study we compared secretin testing results in six confirmed Zollinger-Ellison Syndrome patients using the biologically-derived product and both synthetic products (human and porcine) in a three-way, randomized, single-blind Latin-squares crossover study.

RESULTS

Using the FDA-approved criterion for positive secretin testing (i.e. a serum gastrin concentration increase of > 110 pg/mL), there was complete agreement between all three agents for all patients. With the more stringent NIH criterion (i.e. a serum gastrin concentration increase of > 200 pg/mL), positive results persisted in five out of six, six out of six and four out of six patients using biologically-derived secretin, synthetic porcine secretin, and synthetic human secretin, respectively (six out of six, six out of six and four out of six if a positive test was defined as a 50% increase in serum gastrin concentration). The time to peak serum gastrin concentration after secretin injection occurred within 15 min in all studies (in 94% by 10 min and in 77% by 5 min). Three-way comparisons of serum gastrin concentrations showed a single statistically significant difference (the change from baseline at 15 min between synthetic human and synthetic porcine secretin, P=0.0274). Statistically significant changes from baseline occurred at 1, 2 and 5 min for biologically-derived porcine secretin and at 2 and 5 min for both synthetic porcine and synthetic human secretin, in keeping with the expected time curve for positive tests. All three agents were well-tolerated.

CONCLUSIONS

These data suggest that either synthetic secretin product, when released onto the United States market, can be used to confirm Zollinger-Ellison Syndrome.