Our ASDproteinpattern test is based on AGEomics – a technique that quantifies low level modifications of proteins. The analysis platform is stable isotopic dilution analysis chromatography-tandem mass spectrometry – a highly sensitive and specific technique preferred by regulatory authorities to measure small molecule modifications – such as the measurements made in AGEomics. We measure 16 types of modification, more than any other research teams in the world. We have done so since developing this technique over 20 years ago. Major types of modification are by sugars – called glycation adducts (early and advanced), oxidations – oxidized compounds formed from amino acids, and nitration – nitrated tyrosine – see figure below
Changes in only 4 modification types were linked to the presence of autism: 3 increasing and one decreasing in autism. The changes are combined and given optimum weighting in a diagnostic algorithm developed by artificial intelligence (AI) machine learning for high accuracy diagnosis.
Discovery phase study
This was a study performed by Professor Naila Rabbani, Professor Paul J Thornalley and team at the University of Warwick, Coventry, UK with collaborators at the University of Bologna, Bologna, Italy and University of Birmingham, Birmingham, UK. Sixty-nine children with ASD or typical development (TD) were recruited for the study.
Publication in peer review journal: Anwar, A., Abruzzo, P.M., Pasha, S., Rajpoot, K., Bolotta, A., Ghezzo, A., Marini, M., Posar, A., Visconti, P., Thornalley, P.J. and Rabbani, N. (2018) Advanced glycation endproducts, dityrosine and arginine transporter dysfunction in autism – a source of biomarkers for clinical diagnosis. Molecular Autism 9: 3
https://molecularautism.biomedcentral.com/articles/10.1186/s13229-017-0183-3
The method and algorithms were the basis of a patent application in 2018: WO2019155233 – Methods For diagnosing an autistic spectrum disorder.
Figure: Optimum features and performance of classifier algorithm from Discovery Phase study. Left-side panel: 4 features and changes with ASD. Center panel: Receiver operating characteristic plot. Right-side panel: classification performance.
Validation study
Principal outcome
The principal algorithm from the Discovery Phase study was validated – see Figure below.
Publication in peer review journal: Al-Saei, A.N.J.M., Eldine, W.N., Rajpoot, K., Arshad, N., Al-Shammari, A.R., Kamal, M., Al-Shabeeb Akil, A., Fakhro, K.A., Thornalley, P.J. and Rabbani, N. (2023) Validation of plasma protein glycation and oxidation biomarkers for the diagnosis of autism. Molecular Psychiatry 29, 653 – 659.
Interpretation
Our approach is unique in focusing on biomarkers based on modifications of protein that report on metabolic changes and status of neuronal connections. Adducts linked to the presence of autism are:
- CML – reporting on lipid peroxidation and glucose status;
- CMA – reporting on lipid peroxidation status;
- 3DG-H – reporting on misfolded protein status;
- DT – reporting on neuroplasticity (status of neuronal connections)
FAQS
It is a blood test only applicable to post-natal testing of infants and children to assess the presence of autism. The assessment is based on the measurement of 4 different modifications of plasma proteins combined in a diagnostic algorithm. Then outcome of the test is available within one week.
The test to date has been found applicable to all infants and children from 18 months to 12 years old. It is likely that it is applicable to teenagers and adults too.
The ASDproteinpattern has high accuracy, meets the threshold levels for sensitivity and specificity of the American Psychiatry Association and requires only a small non-fasted blood sample (one tenth of a milliliter). It greatly improves the detection of the absence and presence of autism in children compared to current screening techniques.
The ASDproteinpattern test is currently in the process of preparation for regulatory approval. It is expected that it will be made readily available through current clinical laboratory service providers.
It’s preferable to do the test earlier so that if positive the child can receive a timely referral to child development expert. Our test is applicable to a wide age range, 18 months to 12 years, so if the physician wants to wait for 6-12 months, the test will still be valid. The accuracy and confidence of the outcome is much better than when other techniques are used alone – such as the Modified-Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F) questionnaire and Social Communication Questionnaire (SCQ).
The results are available within one week giving the outcome as to whether the child does or does not have autism.
The ASDproteinpattern test is a screening test. A positive outcome, as per FDA guidance, requires expert referral to a child development expert for confirmation. With a positive outcome, it would be expected that expert referral receives priority
The ASDproteinpattern test is a screening test. A negative outcome means that it is highly likely the child does not have autism and they can continue with typical development and childhood.
The ASDproteinpattern test may be made available through the usual clinical laboratory service providers.
Current ASD genetic testing is rarely diagnostic for autism. The ASDproteinpattern test is useful in all cases because the metabolic changes and neuroplasticity indicated by the protein modification markers in the test likely reflect or are closely related to the mechanisms in the brain producing the autistic symptoms
Some companies have tried to create blood tests for autism by measuring unmodified protein levels in blood plasma. However, these tests do not reflect what’s happening in the brain, and their early promising results could not be confirmed in later studies. The ASDproteinpattern test is different because it measures modified proteins, not unmodified ones.
Other tests have looked at metabolites in the blood. These are generally short-lived changes and do not directly report on changes in the metabolism of the brain. In contrast, the ASDproteinpattern test measures modified proteins that reflect brain metabolism over the previous 3–4 weeks. This makes it more focused on the brain and less affected by short-term changes, such as meals. As a result, no fasting or special preparation is needed before giving a blood sample.
Glossary
- AGEomics : It is a technology that measures low level modifications of proteins by glycation, oxidations and nitration, using an analytical technique that applies stable isotopic dilution analysis chromatography-tandem mass spectrometry.
- Glycation: It is a natural chemical process where sugars (like glucose) attach to proteins, fats, or DNA without the help of enzymes. Over time, this reaction changes the structure and function of these molecules, forming compounds called Advanced Glycation End-products (AGEs).
- Albumin :A major protein found in blood plasma and also in cerebrospinal fluid.
- Algorithm:A process or set of rules followed in calculations that classifies the outcome; for example, positive or negative for autism.
- Artificial intelligence (AI):Artificial intelligence (AI) is the concept of creating machines that can mimic human intelligence. Machine learning is a method for achieving AI, where algorithms find patterns in data to make predictions or classifications.
- AUROC : Area under the curve of a receiving operating characteristic plot. This is often taken as a measure of accuracy of a test – the closer to 100%, the higher the accuracy.
- Autism spectrum disorder (ASD):A group of developmental disorders linked mainly to social interactions, range of interests and a wide spectrum of other disabilities.
- Biomarker:A biochemical, genetic, or physiological characteristic that indicates or reports on a particular condition or process. Biomarkers may be used alone or in combination to assess the condition of an individual.
- Cerebrospinal fluid:A clear, colorless liquid that surrounds and cushions the brain and spinal cord, protecting them from injury, supplying essential nutrients and removing waste products.
- Discovery study : A study where the initial new insight or innovation is made. For example, the study where levels of modified proteins were initially found linked to the presence of autism in children.
- Glucose metabolism : The processes of glucose use in the body; in relation to autism, particularly processes of glucose use by the brain.
- Lipid peroxidation: A biochemical, genetic, or physiological characteristic that indicates or reports on a particular condition or process. Biomarkers may be used alone or in combination to assess the condition of an individual.
- LR- : Negative likelihood ratio. The probability of a person who has the condition testing negative divided by the probability of a person who does not have the condition testing negative.
- LR+: Positive likelihood ratio. The probability of a person who has the condition testing positive divided by the probability of a person who does not have the condition testing positive.
- M-CHAT-R/F : This stands for Modified-Checklist for Autism in Toddlers, Revised with Follow-up questionnaire. It is a screening tool used to identify toddlers aged 16 to 30 months who may be at risk for ASD. It is a two-stage process that includes a parent-completed questionnaire (M-CHAT-R) followed by a brief phone interview for those who score positively on the questionnaire, which is what the "/F" stands for. This tool is not a diagnostic tool but is recommended by organizations like the American Academy of Pediatrics for use as a screening tool for early detection.
- Metabolic change: A change in the use of normal physiological compounds
- Misfolded protein: A protein that has lost its normal or native folding of the polypeptide backbone. This often occurs following spontaneous modification.
- Neuroplasticity: The ability of the brain to form and reorganize connections between neurons, especially during development and in response to learning, experience – including cognitive therapy.
- NPV : Negative predictive value. It is defined as the proportion of negative test results of children that do not have autism.
- PPV : Positive predictive value, or precision. It is defined as the proportion of positive test results of children that do have autism.
- SCQ : This stands for Social Communication Questionnaire. This is a 40-item yes/no parent-report screening tool used to identify children and adults who may have ASD. It is based on the Autism Diagnostic Interview-Revised (ADI-R) and assesses social communication, social interaction, and restricted interests. The SCQ is not a diagnostic tool itself, but rather a screening measure to help determine if a formal diagnostic evaluation is needed.
- Sensitivity :True positive rate. The probability of a positive test result when the child tested has autism
- Specificity : True negative rate. The probability of a negative test result when the child tested does not have autism
- TD : Abbreviation for “Typically developing”. A child who has developed, achieving walking and talking on a timescale similar to the majority of children within the same culture.
- Validation study : A follow-up study testing to see if the same or similar outcome can be found as in an earlier Discovery phase study with totally independent or different study subjects.
Glossary
AGEomics
It is a technology that measures low level modifications of proteins by glycation, oxidations and nitration, using an analytical technique that applies stable isotopic dilution analysis chromatography-tandem mass spectrometry.
Glycation
Albumin
Algorithm
Artificial intelligence (AI)
AUROC
Autism spectrum disorder (ASD)
- Speech disturbances
- Repetitive and/or compulsive behaviors
- Hyperactivity
- Anxiety
- Difficulty to adapt to new environments
- With or without cognitive impairment