Insight
continue research
We are constantly striving to develop dietary solutions that improve the therapeutic efficacy and quality of life of people with particular medical conditions. In this section you can find scientific information on the disorders and diseases we deal with. Use the menu below to find out more about the areas you are interested in.
.
Insight
Phenylketonuria and other aminoacidopathies
Phenylketonuria, or PKU, is a metabolic genetic disease that leads to the surplus of phenylalanine (Phe) amino acid in the body. This anomaly appears due to the defective phenylalanine hydroxylase (PAH) gene encoding the enzyme which converts phenylalanine to tyrosine (Tyr). Phenylalanine is an essential amino acid for the protein synthesis, so it cannot be produced by body itself but it must be introduced through daily diet in the adequate amount to guarantee growth and repair of body tissues. In subjects affected by PKU the conversion failure causes an accumulation of phenylalanine in blood and in the brain, which affects the normal operations of the main brain messengers, including dopamine and serotonin, causing mental disability, neurological and behavioral disorders. PKU can be easily diagnosed through neonatal screening between 48 and 72 hours after birth. It has been mandatory by law n°104/1992 and it has been expanded to other 40 pathologies by law 167/2016. In case of families-at-risk and when the possible mutations can be predicted, it is possible to make a prenatal diagnosis by genetic analysis.
Phenylketonuria is an autosomal recessive genetic disease, which occurs when both genes for PAH are “defective”. The position and nature of the mutation in the genes determine the effects on the activity of the PAH enzyme and consequently the severity of the pathology, that is classified as mild, moderate or classic/severe, based on the values in the Phe blood reached on a free diet. Another variant is due to the gene mutation for the synthesis or regeneration of the enzymatic cofactor tetrahydrobiopterin (BH4).
Approximately 1 out of 50 people has a defective PKU gene, meaning that he is a still immune carrier. There is a little chance that two carriers will encounter each other – only about 1 out of 2500, and for this reason PKU is defined as a rare disease: in Europe the annual number of children born with PKU is 1/10.000 born alive.
Waiting for future treatments like enzyme replacement therapy or gene therapy, the dietetic treatment is the only actually therapy for the management of PKU. To avoid damage, the dietetic restriction must start from the first month of life, guaranteeing an adequate intake of energy and protein based on age and a controlled amount of phenylalanine.
The dietetic treatment consists in:
– Consumption of fruit, vegetables and limited number of foods;
– Use of low-protein substitutes of common foods to cover energy needs (Taranis / Harifen products);
– Use of amino acid mixtures to cover individual protein needs (Numefen / Antifen line);
– Restriction of foods naturally containing proteins such as meat, eggs, legumes, milk, cheese, pasta, bread and derivatives, carbonated drinks containing aspartame;
Although long-term studies are needed to evaluate efficacy and safety, an alternative to the traditional dietary treatment is the use of mixtures with “Large neutral amino acids” (LNAAs) (Antifen Arancia, Antifen R) that compete with the phenylalanine at the level of the LAT1 transporter in the blood-brain barrier. This alternative ensures a less rigid diet combined with a reduction in Phe values in the brain. Further alternatives can be the use of prolonged absorption amino acids mixture and glycomacropepetide (GMP).
Insight
Chronic renal failure
The term "chronic renal failure" identifies the progressive loss of the purifying functions of the kidney due to various types of nephropathies. This condition is always irreversible and its development can be gradual or sudden. The kidneys filter blood from lot of dangerous substances including nitrogenous ones that derive from protein metabolism, set hydro saline balance for arterial pressure, acid-base balance for blood acidity, and regulate calcium, phosphorous, vitamin D metabolism. They product erythropoietin hormone too that regulate the amount of red blood cells. In the initial stage the only occurring symptom might be the need to urinate several times during the night, whereas at the subsequent phase the nitrogen levels increase and evoke the need to urinate more frequently also during the day. The deterioration of general condition indicated by paleness, poor appetite and fatigue appear in the terminal phase. In addition to these symptoms, there can appear others such as: high blood pressure, cardiocirculatory failure or acute pulmonary edema, respiratory disorders, anemia, lymphopenia, sleep disorders, difficulties in concentration, peripheral neuropathies.
The main diseases that can lead to this problem are: diabetes; hypertension; lupus; recurrent kidney infections; kidney stones; renal cysts; blood infection, or the so-called sepsis; constant usage of painkillers, alcohol and other drugs.
In the early stages of the disease, in order to keep the chronic renal failure under control, one can rely on a conservative therapy based on a diet, lifestyle changes and medications, diuretics and antihypertensives. When the residual renal function is no longer sufficient to cover the needs of the organism, the resort is to rely on the other replacement therapy: hemodialysis, in which the blood is being purified 3 three times a week for about 4 hours each time in hospital, or peritoneal dialysis, which is a more physiological variant than the previous one, and can be carried out during the night rest. However, it requires a certain cooperation from the patient. In rapidly changing forms, when there are no contraindications, the kidney transplant might be recommended. A special diet is one of the cornerstones in a conservative therapy. The patients are advised to stick to a diet that is low in proteins and low in phosphorus, or even slightly low in salt and high in calories. An adequate protein intake (thus, also phosphate intake) plays an important role in the conservative treatment of chronic renal failure because it allows:
– the control of the urea levels, phosphorus and parathyroid hormone;
– the control of acid-base balance (particularly in the case of metabolic acidosis);
– the maintenance of a satisfactory nutritional status;
– a possible slowdown of the progressing renal failure which otherwise brings to the terminal uremia.
