Nutritional Assessment of Patients Affected by Porphyria Variegata

Nutrients and Porphyria: An Intriguing Crosstalk

Porphyria refers to a group of fascinating diseases from a metabolic and nutritional standpoint as it provides an example of how metabolic manipulation can be used for therapeutic purposes. It is characterized by defects in heme synthesis, particularly in the erythrocytes and liver. Specific enzymes involved in heme biosynthesis directly depend on adequate levels of vitamins and minerals in the tissues. Moreover, micronutrients that are required for producing succinyl CoA and other intermediates in the Krebs (TCA) cycle are indirectly necessary for heme metabolism. This review summarizes articles that describe the nutritional status, supplements intake, and dietary practices of patients affected by porphyria, paying special attention to the therapeutic use of nutrients that may help or hinder this group of diseases.

Haem Biosynthesis and Antioxidant Enzymes in Circulating Cells of Acute Intermittent Porphyria Patients

The aims of the present study were to explore the expression pattern of haem biosynthesis enzymes in circulating cells of patients affected by two types of porphyria (acute intermittent, AIP, and variegate porphyria, VP), together with the antioxidant enzyme pattern in AIP in order to identify a possible situation of oxidative stress. Sixteen and twelve patients affected by AIP and VP, respectively, were analysed with the same numbers of healthy matched controls. Erythrocytes, neutrophils and peripheral blood mononuclear cells (PBMCs) were purified from blood, and RNA and proteins were extracted for quantitative real time PCR (qRT-PCR) and Western-blot analysis, respectively. Porhobilinogen deaminase (PBGD) and protoporphyrinogen oxidase (PPOX) gene and protein expression was analysed. Antioxidant enzyme activity and gene expression were additionally determined in blood cells, together with protein carbonyl content in plasma. PBMCs isolated from AIP patients presented low mRNA levels of PBGD when compared to controls, while PBMCs isolated from VP patients presented a decrease in PPOX mRNA. PPOX protein content was higher in AIP patients and lower in VP patients, compared to healthy controls. Regarding antioxidant enzymes, PBMCs and erythrocyte superoxide dismutase (SOD) presented statistically significant higher activity in AIP patients compared to controls, while catalase activity tended to be lower in these patients. No differences were observed regarding antioxidant gene expression in white blood cells. Circulating cells in AIP and VP patients present altered expression of haem biosynthetic enzymes, which could be useful for the differential diagnosis of these two types of porphyria in certain difficult cases. AIP patients present a condition of potential oxidative stress similar to VP patients, evidenced by the post-transcriptional activation of SOD and possible catalase impairment.

Assessing nutritional status of acute intermittent porphyria patients

BACKGROUND

Acute intermittent porphyria (AIP) is a metabolic disease of haem synthesis, whose haem precursors may accumulate in the body. A well-balanced diet may prevent the symptoms, so that porphyric patients should be monitored closely during therapy for possible complications concerning any progression of acute porphyria. The aim was to evaluate the nutritional status of patients with AIP and to assess their compliance with nutritional recommendations, comparing the findings with a control group and assessing any possible nutritional deficiency.

MATERIAL AND METHODS

Sixteen patients with AIP and a control group were evaluated by means of a lifestyle questionnaire, the Nutrition Screening Initiative checklist and a dietary questionnaire. The following diet quality indicators were calculated: animal and vegetal proteins, protein quality index, PUFA/SFA and MUFA + PUFA/SFA ratios, insoluble dietary fibre (DF)/total DF, soluble DF/total DF and insoluble DF/soluble DF ratios, thiamine, riboflavin and niacin density and the vitamin B6/protein ratio.

STATISTICAL METHODS

Differences in continuous variables were compared using the unpaired Student's t-test and the chi-square test for nonparametric variables. The odds ratio (OR) of malnutrition was also used.

RESULTS

Our patients showed a low intake of carbohydrates, a high lipid intake and very high protein intake, and accompanied by an inadequate intake of zinc, folic acid and tocopherol, increasing the risk of malnutrition for energy, Ca, Fe, Mg, K, folic acid and tocopherols.

CONCLUSIONS

The patients with AIP studied individually show an increased risk of malnutrition and, given the potential increase of oxidative stress in patients with porphyria, it is recommended that they should increase their intake of carbohydrates, minerals and antioxidant nutrients.