Hemocromatosis hereditaria: génetica y diagnóstico / Hereditary Hemochromatosis: genetics and diagnosis

La hemocromatosis hereditaria (HH) es una enfermedad autosómica recesiva, que se caracteriza por un incremento de la absorción intestinal del hierro de la dieta y su acumulación en distintos órganos. Es la enfermedad hereditaria más frecuente en la raza blanca. El gen asociado con la HH está relacionado con el sistema HLA de clase I. Este gen codifica una proteína similar a las moléculas de este complejo, denominada HFE, que interacciona con el receptor de la transferrina (R-Tf) y disminuye su afinidad por la transferrina diférrica. La mayoría de los pacientes con HH producen una proteína mutada incapaz de interaccionar con el R-Tf, lo que conduce a un aumento de la absorción de hierro. La enfermedad se manifiesta en homocigotos no tratados y se caracteriza por hepatomegalia, cirrosis hepática, pigmentación de la piel, diabetes mellitus, enfermedad cardíaca, artritis e hipogonadismo hipotalámico. La cantidad total de hierro y su distribución en distintos órganos se pueden evaluar por medio de sideremia, capacidad total de saturación de la transferrina, índice de saturación de la transferrina, ferritina sérica y eritrocitaria, hierro no unido a la transferrina, hierro excretado por orina luego de inyectar desferroxiamina, flebotomía cuantitativa, biopsia hepática, concentración en índice de hierro hepático, tomografia computada y resonancia magnética nuclear. Actualmente, es posible determinar mutaciones en el gen HFE mediante técnicas de génetica molecular. El diagnóstico y el tratamiento tempranos ayudan a prevenir o reducir el daño tisular y la muerte prematura

Urinary iron children with nephrotic syndrome

Urinary transferrin loss is a typical feature in relapse of the idiopathic nephrotic syndrome [I.N.S.], also, there is increased urinary iron in animals and humans with nephrotic syndrome. Urinary N-acetyl-beta-D- gluosaminidase [NAG] is indicator for renal damage. To estimate the urinary iron and urinary NAG in children with idiopathic nephrotic syndrome, and the possible role of iron in the different histopathological types of the disease. Our study was performed on 2 groups of patients, minimal change nephrotic syndrome [MC NS] group 10 children [6 boys and 4 girls] mean age 9.75 +/- 2.2 years, focal segmental glomerulosclerosis. [FSGS] group 8 children [5 boys and 3 girls] mean age 9.63 +/- 1.9 years with 12 children [7 boys and 5 girls] of matched ages as a control group. Laboratory parameters hemoglobin concentration [HB], serum albumin, serum iron, serum ferritin, serum transferrin, serum creatinine, BUN, urinary protein per 24 H, urinary transferrin, urinary iron and urinary NAG were evaluated. The results proved decrease in HB in both group of N.S., decrease serum albumin, serum iron, serum ferritin and serum transferrin in both groups of N.S. especially FSGS and significant increase in urinary protein per 24H, urinary transferrin, urinary iron and urinary NAG in both groups of N.S especially FSGS group. There was an increased urinary transferrin and this is accompanied by corresponding increase in a reactive iron species and this could incite tubulo-interstitial injury and renal damage. Measuring urinary iron and urinary NAG could be a respectable method for follow up and prediction of the prognosis in children with idiopathic nephrotic syndrome

Study of urinary transferrin and iron excretion in insulin dependent diabetes mellitus [IDDM] with variable degrees of albuminuria

This study included 60 insulin dependent diabetic male patients in 3 groups according to urinary albumin excretion. Group I with normal albuminuria [urine albumin < 30 mg/day], group II with microalbuminuria [urine albumin 30-300 mg/day] and group III with macroalbuminuria [urine albumin > 300 mg/day]. Each diabetic group included 20 cases and these groups were compared with control group comprised of 20 healthy subjects. The present work was undertaken to study urinary transferrin and iron in diabetic patients with varying amounts of albuminuria. The following were the results of this work: -There was significant increase [P < 0.05] in urinary transferrin and iron in all the studied diabetic groups compared to the normal controls, and this increase occurrs early in the course of the diabetic renal disease. -The iron/transferrin ratio in urine was much higher than that in serum in all the diabetic groups. This means that iron is present in the urine in marked excess than its carrier transferrin. -There was significant positive correlation [P < 0.05] between urinary albumin and urinary transferrin in both the micro and macro albuminuric diabetic groups. -There was significant positive correlation [P < 0.05] between urinary albumin and urinary iron in all the diabetic groups. -There was significant positive correlation [P< 0.05] between urinary iron and urinary transferrin in the macroalbuminuric diabetic group. From this work we can conclude the following: -Transferrin which has the similar molecular size as albumin, its urinary excretion in excess as well as the excess excretion of urinary iron in diabetics may suggest the possibility of development of glomerular disease and nephropathy. -Urinary iron excretion is increased early in the course of diabetic renal disease. The fact that iron is present in the urine in marked excess of transferrin further suggests that either iron is dissociated from transferrin in the tubule fluid with transferrin being reabsorped, or that iron is added to the tubule fluid by means other than filtration without transferrin. This finding suggests that iron could be present in tubule fluid in a form which would catalyze the Haber- Weiss reaction with the formation of free radicals resulting in tubulointerstial injury. -The increase of urinary iron excretion in diabetics may reduce iron stores making the individuals more at risk of developing iron deficiency if there are other causes of iron or blood loss. We recommended detection of urinary transferrin and iron in IDDM patients as their excretion in excess may suggest the possibility of development of glomerular disease and nephropathy which may need further investigations and follow up for proper management of this risky diabetic complication

Comparison between the excretion of some metallic elements in normal and parasitized human

Twenty four hours urine samples from a total of 50 normal healthy individuals [30 males and 20 unmarried females] and a total of 70 parasitized patients [40 urinary schistosomiasis males and 30 trichomoniasis females] were analysed for zinc, copper, iron, calcium, magnesium, potassium and sodium. The results showed that urinary schistosomiasis leads to increased zinc, iron, calcium, magnesium and potassium levels but decreases the excretion of sodium, where as trichomoniasis leads to increase the excretion of zinc and sodium but decrease the excretion of copper. No significant differences were found in the biochemical element excretion between filtered and unfiltered urine samples during both infections

Iron excretion in thalassemia children treated with deferoxamin methansulfonat: intravenous drip compared to the subcutaneous routes.

The iron excretion in the three beta-Thal/Hb E patients were determined comparing the effect of DF given by subcutaneous push, subcutaneous drip and intravenous drip. The subcutaneous drip or intravenous drip increased urine iron excretion by 5.6-11.2 times whereas the subcutaneous push, 3.5-5.3 times only. It is recommended that for countries where the infusion machine is very expensive the DF should be given by intravenous drip or the modified, simple and inexpensive equipment for subcutaneous drip.

Relación hierro/creatinina en orina basal: su utilidad como indicador del estado nutricional respecto del hierro / Iron/creatinine ratio in basal urine: its usefulness as nutritional status indicator with relation to iron

La excreción urinaria de ciertos nutrientes o sus metabolitos, en orina basal, puede ser utilizada como indicador dinámico de estado nutricional cuando se la relaciona a la de creatinina. Basándose en este conocimiento hemos analizado la potencial utilidad de la relación hierro/creatinina (Fe-Creat) como indicador de estado nutricional respecto del hierro. Para ello se estudió la relación Fe/Creat comparativamente con otros indicadores utilizados habitualmente: presencia de anemia, protoporfirinas libres de glóbulo rojo (FEP) y ferritina sérica. Se estudiaron 24 niños de 3 a 36 meses de edad, que por causas legales permanecieron durante 60 días internados en el Hospital Noel H. Sbarra, La Plata. Durante ese período los niños fueron alimentados ad libitum, registrándose la ingesta diaria de hierro a través del registro del consumo de alimentos. Al comienzo y al final del estudio se consideró anémico a todo niño con una concentración de hemoglobina inferior a 11g/dl y desnutrido a todo aquel con una relación peso para la talla inferior a 10% del valor del 50 percentilo de las Curvas de Crecimiento y Desarrollo de La Plata. Según estos criterios, se establecieron los siguientes grupos: a) eutróficos, no anémicos, durante todo el estudio; b) eutróficos, anémicos al ingreso, no anémicos al final del estudio, y c) desnutridos al ingreso, que se subdividieron según la situación al final del estudi en: C1: eutróficos, no anémicos; C2: eutróficos, anémicos; C3: desnutridos, con independencia de su estado hematológico. Los resultados evidenciaron, al final del estudio, una correlación directa entre la relación Fe/Creat. y la ingesta de Fe, para los grupos A y B: Y=0,014X+0,013; r=0,54; y C1: Y=0,0036X+0,0006, r=0,89; en los grupos C2 y C3 la relación permaneció constantemente baja e independiente de la ingesta. La relación Fe/Creat vs las FEP presentó, para los grupos A, B y C1 una relación inversa: Y=...

Limites biológicos em higiene e medicina do trabalho

O controle biológico de trabalhadores expostos a agentes químicos agressivos coloca o médico do trabalho frente a uma série de problemas conjunturais e estruturais de difícil soluçäo. A partir de pesquisa onde foram analisadas urina de 58 soldadores para determinaçäo de concentraçäo de Mg, Zn, Cu, Mn, Fe, Cd, Cr, Ni säo discutidas as dificuldades da execuçäo deste controle, incluindo aspectos ambientais. Conclui-se pela importância das avaliaçöes biológicas, mas ressaltando a prioridade para as medidas ambientais de controle dos agentes químicos