Study of University of São Paulo Shows Amplified Foot Test increases disease detection and replaces the traditional test in SUS
Neonatal screening is important so that, early on, there is a diagnosis of diseases and referral for treatment. Included in this list of exams is the heel prick test, which aims to identify and treat “metabolic, genetic, enzymatic and endocrinological diseases” at an early stage.
The test is carried out after 48 hours of life by means of a pulsation in the newborn’s heel and, until recently, it was possible to detect only six diseases through this test. However, thanks to the development of disease markers, using the technique of Trec (they detect defects in T lymphocytes) and Krec (they detect defects in B lymphocytes), it is now possible to diagnose more than 50 diseases.
“We were able to diagnose an element of diseases that refer to the adaptive immune system, the one that remembers infections, the memory of vaccines and antibodies: the so-called cellular immunity”, says Professor Antônio Condino Neto, from the Institute of Biomedical Sciences from USP and winner of the Dasa Biomedical Innovation Award due to this advance. Currently, there are about 85 diseases related to the immune system that can be detected using these two markers.
Perspectives for the SUS
In May of last year, the Executive sanctioned Law nº 14,154 , which improves the National Neonatal Screening Program, “ through the establishment of a minimum list of diseases to be screened by the heel prick test”. Thus, mitochondrial, immunological, metabolic diseases and inborn errors of immunity are contemplated.
“Here at USP, over the last ten years, we have been developing markers for the detection of inborn errors of immunity in our laboratory at the Instituto de Ciências Biomédicas and Laboratório de Immunologia Humana (…) we can now identify more than 85 diseases officially with a potential to reach up to 200”, says the professor.
The good news is that this federal law establishes a four-year deadline for universal implementation in the SUS. Antônio Condino Neto points out that, in the city of São Paulo, the Extended Foot Test is already in practice and, through it, 8 thousand tests for detection of innate immunity errors are carried out per month.
“We did approximately 200,000 children from the part of inborn errors of immunity.” The test is a success: it has been possible to detect, so far, seven babies with severe combined immunodeficiency and one with congenital leukemia, something unprecedented in the medical literature. The test is also already being carried out in the State of Minas Gerais and there is the prospect that it will be expanded in the State of São Paulo and in the southern region of the country, which is moving towards its implementation.
The professor comments that, in São Paulo, the frequency of detected diseases is twice as high as those reported in the United States and Europe: “Probably because our genetics are different, whether it is more frequent here in our environment, or perhaps because the technology that people have developed here is more perfected, more sensitive”.
Another law was recently passed, which obliges hospitals to explain the modalities of the Guthrie Test to parents, which means progress in this area.