Insidious peripheral neuropathy occurring under treatment in infantile MTHFR deficiency.

5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency was diagnosed in a 1-month-old baby with signs of cerebral distress. Under a classic treatment using methionine supplementation, methyl donor (betaine) folinic acid, vitamin B(6) and vitamin B(12), the neuromotor development was satisfactory. At 15 years of age, however, despite no clear modification of the biochemical markers in body fluids, she developed a clinically overt peripheral axonal neuropathy. Only partial clinical improvement was obtained after reinforcement of betaine doses. Surveillance of the peripheral nerve is indicated in MTHFR deficiency, including in the infantile form with a good therapeutic compliance.

Fluorouracil combined with the pure (6S)-stereoisomer of folinic acid in high doses for treatment of patients with advanced colorectal carcinoma: a phase I-II study.

BACKGROUND: Potentiation of the antitumor activity of fluorouracil (5-FU) by folinic acid has been demonstrated in patients with colorectal adenocarcinoma. Modulation is due to the interaction of thymidylate synthase, fluorodeoxyuridine monophosphate, and methylene tetrahydrofolate, which leads to the formation of a stable ternary complex with concomitant enzyme inactivation. Folinic acid consists of a mixture of equal parts of two stereoisomers differing in chirality at the C-6 carbon of the pteridine ring. Only the levorotatory (6S)-stereoisomer of folinic acid is transformed into active folate cofactors. However, the (6R)-stereoisomer of folinic acid is not inert; it was shown to interfere with the (6S) form at the cellular level. PURPOSE: The possibility of a deleterious effect of the unnatural stereoisomer on the modulation of 5-FU led us to carry out a phase I-II study of 5-FU combined with the (6S)-stereoisomer of folinic acid given in high doses for treatment of patients with advanced colorectal carcinoma. We also determined the plasma pharmacokinetics of folates after intravenous (IV) injection of (6S)-folinic acid at the dose used in this study. METHODS: Treatment consisted of 5-FU (350-550 mg/m2 per day by IV infusion for 2 hours) and (6S)-folinic acid (100 mg/m2 per day by IV bolus injection) given for 5 consecutive days; the treatment was repeated every 21 days. Twenty-five patients with advanced colorectal carcinoma, who had had no prior chemotherapy, were evaluated for antitumor activity. The quantity of folates in plasma was measured using a microbiological assay. RESULTS: The median follow-up time was 9 months (range, 3.5-15.2 months). The response rate was 52% (complete response, 12%; partial response, 40%). The median time to disease progression for responding patients was 9.2 months (range, 5.9-15+ months). The estimated probability of survival at 12 months was 73%. Palliative improvement in quality of life was achieved in most patients who had symptoms due to the tumor before the start of treatment. The dose-limiting toxic effects were grade 3 diarrhea, dermatitis, and oral mucositis. Grade 4 toxicity did not occur. Myeloid toxicity was minor. After IV injection, (6S)-folinic acid was rapidly cleared from plasma (mean half-lives: alpha = 7.2 minutes and beta = 126 minutes). The mean concentration of the unchanged compound 2 hours after injection was 5.8 mumol/L. CONCLUSION: The (6S)-form of folinic acid potentiates the antitumor effect of 5-FU given concomitantly. IMPLICATION: Our results justify a more complete exploration of the pure active stereoisomer as a modulator of the fluoropyrimidines.

Modulation of 1-beta-D-arabinofuranosylcytosine metabolism by thymidine in human acute leukemia.

Twenty-seven patients with acute leukemia have been treated by sequential 6-day courses of thymidine (30 g/m2 by i.v. continuous infusion, days 1 and 4) and 1-beta-D-arabinofuranosylcytosine (ara-C) (200 mg/m2 by i.v. continuous infusion, days 2,3,5, and 6). Of 25 evaluable patients 4 achieved a complete remission: one of 9 for acute myelogenous leukemia; and 3 of 14 in the blastic crisis of chronic myelocytic leukemia. Six minor responses were also observed. Toxicity was mainly hematological and did not appear to be higher than that expected from ara-C alone. However, thymidine infusions gave rise to headache and somnolence. The clinical benefit of such treatment seems to be limited to the blastic crisis of chronic myelocytic leukemia. Parallel cytokinetic and biochemical studies were performed in order to assess the cytokinetic and metabolic changes induced by both drugs and to correlate them with the clinical response. Recruitment of cells into the S-phase fraction was observed following the first thymidine infusion in the two complete responders and in three of the five nonresponders studied. In contrast to this high pretherapeutic levels of S-phase fraction were observed in most minor responders and in some nonresponders with further decrease following the thymidine infusion. Recruitment of cells into S phase therefore appeared to be an important but not sufficient factor for prediction of complete response to ara-C. Responders in contrast to most nonresponders were characterized by a higher intracellular level of ara-C and its metabolites following the first 24-h infusion of the drug. Deoxythymidine triphosphate and deoxycytidine triphosphate pools were also measured before and during treatment in order to assess if nucleotide pool variations induced by the administration of thymidine can in fact correlate with the intracellular alteration in ara-C metabolism and with clinical response. The level of deoxycytidine triphosphate pools before treatment showed marked interpatient variations but did not correlate with response. As expected, thymidine infusion induced a rise in the deoxythymidine triphosphate pool and a decrease in deoxycytidine triphosphate. The pools, however, generally returned promptly to the pretherapeutic level 24 h after the end of the infusion of thymidine. There were no significant differences between responders and nonresponders in the modulation of these pools.

Treatment of advanced colorectal and gastric adenocarcinomas with 5-fluorouracil and high-dose folinic acid.

We report the results of an expanded trial of 5-fluorouracil (5-FU) combined with high-dose folinic acid for treatment of patients with advanced colorectal or advanced gastric adenocarcinoma. In each treatment course, the patients received both 5-FU (340 to 400 mg/m2/d by intravenous (IV) infusion for a period of 15 minutes) and folinic acid (200 mg/m2/d by IV bolus) for 5 consecutive days, with a 21-day interval between courses. Eighty-six patients with colorectal carcinoma were evaluated. The combined complete and partial response rates were 39% for 54 patients who did not receive prior chemotherapy and 22% for 32 patients who had previously received chemotherapy. Four patients who were previously resistant to 5-FU attained objective responses. The median time to disease progression for the 28 responders was 10 months. The median survival time of responders was 19.5 months, and the probability of their being alive at 2 years was 40%. Of 27 patients with gastric adenocarcinoma, 13 (48%) responded to therapy. Their median time to disease progression was 5.5 months. The median survival time of responders was 11 months, and their probability of being alive at 15 months was 30%. Toxicity was within acceptable limits. Toxic effects included stomatitis, diarrhea, conjunctivitis, skin rash, and mild myeloid hypoplasia. In a separate study, plasma concentrations of L-folates greater than 10(-5) mol/L were achieved after a rapid single IV injection of 200 mg/m2 of folinic acid. Comparisons of our results with those reported in previous studies on 5-FU administered as a single agent suggest that, in advanced colorectal and gastric adenocarcinoma, folinic acid administered in high doses enhances the effectiveness of 5-FU administered concomitantly. Furthermore, some colorectal tumors that were previously resistant to 5-FU become sensitive to this drug. The survival of the patients who responded to therapy was markedly improved over that observed in reported series of untreated patients with advanced colorectal and gastric adenocarcinomas.

Modern clinical testing strategies in cobalamin and folate deficiency.

Folate or cobalamin deficiencies are usually detected by hematologic abnormalities, such as a macrocytic megaloblastic anemia, or often milder signs, such as hypersegmented neutrophils. In fact, these vitamin deficiencies may be associated with clinical conditions in which anemia and/or macrocytosis are absent, such as neuropsychiatric disorders and inborn errors of folate or cobalamin metabolism. A battery of sensitive tests, including blood vitamin levels, serum methylmaIonic acid and homocysteine assays, and the deoxyuridine suppression test in the bone marrow, allows for early detection of vitamin deficiency. Additional tests may be included to identify the causes of deficiency, such as the Schilling test using crystalline cyanocobalamin, or a modified Schilling test for showing food cobalamin malabsorption. Strategies for diagnosing a vitamin deficiency differ according to the hematologic and clinical presentations. The deleterious effects (aside from anemia) that arise from cobalamin or folate deficiency and include neurological complications, increased risk of vascular disease due to hyperhomocysteinemia, and increased risk of some types of cancer related to folate deficiency, underscore the importance of making an early diagnosis and instituting treatment with the appropriate vitamin in preventing permanent damage.

Homocystinuria due to 5,10-methylenetetrahydrofolate reductase deficiency revealed by stroke in adult siblings.

Three patients from a single family of six siblings had homocystinemia and homocystinuria due to 5,10-methylenetetrahydrofolate reductase deficiency and had severe recurrent strokes in adult life. Two of the patients died 1 year after clinical onset.

Cytotoxic synergism of methioninase in combination with 5-fluorouracil and folinic acid.

Potentiation of the cytotoxic activity of 5-fluorouracil (FUra) by folinic acid (5-HCO-H4folate) is due to elevation of the methylene tetrahydrofolate (CH2-H4folate) level, which increases the stability of the ternary complex of thymidylate synthase (TS), fluorodeoxyuridine monophosphate, and CH2-H4folate that inactivates the TS. Methionine deprivation results in the production of tetrahydrofolate (H4folate) and, subsequently, CH2-H4folate from methyl tetrahydrofolate, as a consequence of the induction of methionine synthesis. We hypothesized that the efficacy of FUra could be augmented by the combination of high-concentration 5-HCO-H4folate and recombinant methioninase (rMETase), a methionine-cleaving enzyme. Studies in vitro were performed with the cell line CCRF-CEM. Cytotoxic synergism of FUra + rMETase and FUra + 5-HCO-H4folate + rMETase was demonstrated with the combination index throughout a broad concentration range of FUra and rMETase. A subcytotoxic concentration of rMETase reduced the IC50 of FUra by a factor of 3.6, and by a factor of 7.5, in the absence and in the presence of 5-HCO-H4folate, respectively. 5-HCO-H4folate increased the intracellular concentrations of CH2-H4folate and H4folate from their baseline levels. Concentrations of folates were not changed by exposure to rMETase. Levels of free TS in cells treated with FUra + 5-HCO-H4folate and with FUra + rMETase were lower than those in cells exposed to FUra alone. The decrease of TS was still more pronounced in cells treated with FUra + 5-HCO-H4folate + rMETase. The synergism described in this study will be a basis for further exploration of combinations of fluoropyrimidines, folates, and rMETase.

Mechanism of inhibition of DNA ligase in Ara-C treated cells.

The activity of DNA ligase, the enzyme involved in ligation of DNA fragments and also in DNA repair is inhibited by Ara-C. The exposure of two human leukemic cell lines, K562 and HL-60 to 10(-5) M Ara-C for 3 h, induces a decrease of DNA ligase activity by 40% in K562 and 92% in HL-60. This decreased activity is due to an inhibition by Ara-CTP of the ligase-adenylate complex generation, the crucial step in the action of this enzyme. The activity of the semi-purified ligase as well as the formation of ligase-adenylate complex are decreased in the presence of Ara-CTP. These results demonstrate that Ara-C via its active form Ara-CTP inhibits DNA ligase activity through the inhibition of the ligase-adenylate complex. Other inhibitors of DNA synthesis, such as hydroxyurea, do not exert the same inhibitory effect. The inhibition of DNA ligase activity may be partly responsible for the cytotoxicity of Ara-C.

Methylenetetrahydrofolate reductase deficiency in four siblings: a clinical, biochemical, and molecular study of the family.

A diagnosis of methylenetetrahydrofolate reductase (MTHFR) deficiency was made in four sibs at different ages. The first three, including a pair of twins, had retarded psychomotor development, poor social contact, and seizures. Biologically, hyperhomocysteinemia and hypomethioninemia were found associated with low folate levels in serum and red cells, especially undetectable methyltetrahydrofolate in red cells. In the fourth child, prenatal diagnosis was not conclusive because of moderate decrease of enzymatic activity in chorionic villi and trophoblast. The girl was also affected, as shown by hyperhomocysteinemia and low folate levels found several days after birth. A 677C-->T (Ala-->Val) mutation was found in a homozygous state in the four children and in the father. Additionally, a second homozygous mutation, 1081C-->T, changing an arginine to cysteine also was identified in all of the children, whereas the distantly consanguineous parents were heterozygous. This amino acid substitution affecting an arginine residue in a sequence located at the end of catalytic domain seems critical for the function of the enzyme. The difficulty of prenatal diagnosis is discussed given the variability found in enzymatic activity and in the clinical phenotypes.

Prophylaxis of folate deficiency in acutely ill patients: results of a randomized clinical trial.

A trial was carried out of prophylaxis of folate deficiency in 105 acutely ill patients immediately following admission to an ICU with evaluation of folate status. These patients were fed either orally or by enteral or parenteral nutrition. Three groups were established regardless of the type of nutrition: - Group 1 received 5 mg/day parenteral folinic acid; - Group 2 received 50 mg/week parenteral folinic acid; - Group 3 received no parenteral folinic acid. Before treatment, 19% of the patients presented very low serum folate levels (less than 2.7 ng/ml). Two of them developed acute folate deficiency with severe hematological disturbances quite reversed with folinic acid. Folate levels were inversely correlated with the severity of the clinical status and were lower in septic and feverish patients. The effect of folinic acid administration was assessed after seven days of treatment: daily administration of 5 mg folinic acid appeared to be the best regimen with normalization of serum folate levels in all cases; results appeared to be better than with 50 mg once weekly. Oral and enteral administration of folate supplies considered to be physiological (300 micrograms/day folic acid) did not appear to be sufficient to normalize in all cases blood folate levels in these acutely ill patients.

Plasma homocysteine levels related to interactions between folate status and methylenetetrahydrofolate reductase: a study in 52 healthy subjects.

Hyperhomocysteinemia, a risk factor for vascular disease, is related to vitamin B12, vitamin B6, and especially folate deficiency, or to genetic factors such as mutations in methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in the remethylation pathway of homocysteine to methionine. Recently, a C677 --> T mutation identified in the MTHFR gene was found to be frequently associated with decreased MTHFR activity and an elevated plasma homocysteine concentration. Since hyperhomocysteinemia seems to be determined by both genetic and environmental factors, we studied the interactions between MTHFR (phenotype and genotype) and folate status, including methyltetrahydrofolate (methylTHF), the product of MTHFR, on the homocysteine concentration in 52 healthy subjects, (28 women and 24 men; mean age, 32.7 years). MTHFR activity seems to be dependent on folate status, as shown by a lower activity in folate-deficient subjects and a return to normal values after supplementation with folic acid, and also by a decreased enzymatic activity on phytohemagglutinin (PHA)-stimulated lymphocytes grown in a folic acid-deficient medium. Conversely, the C677 --> T mutation seems to influence folate metabolism. Subjects who were homozygous for this mutation (+/+) had significantly higher plasma homocysteine and lower plasma folate and total and methylfolate levels in red blood cells (RBCs) than heterozygous (+/-) and normal (-/-) subjects. The ratio of RBC methylfolate to RBC total folate was, respectively, 0.27 in +/+, 0.66 in +/-, and 0.71 in -/-. This mutation seems to have an impact on methylTHF generation. These data illustrate the interactions between nutritional and genetic factors.

A study of the mechanisms of cytotoxicity of Ara-C on three human leukemic cell lines.

The main biochemical determinants involved in cytosine arabinoside (Ara-C) metabolism were studied in one lymphoblastic (Reh) and two myeloid (HL60 and K562) human leukemic cell lines exhibiting various sensitivities to Ara-C, Reh being the most and HL60 the least sensitive. The level of intracellular Ara-C accumulation and Ara-CTP formation was far more important in Reh cells than in myeloid cell lines but was not closely related to deoxycytidine kinase activity or to deoxycytidine triphosphate pool size. The level of Ara-C incorporated into DNA was similar in the three cell lines. Ara-CTP formation correlated better with the cytotoxicity to clonogenic cells than did Ara-C incorporation into DNA. DNA polymerase alpha was moderately inhibited to various degrees, depending on the cell line; this moderate inhibition does not seem sufficient to explain the inhibition of DNA synthesis. The activity of DNA ligase, the enzyme joining the Okazaki fragments, which was not detected in Reh cells, was strongly inhibited by Ara-C in HL60 and to a lesser degree, in K562 cells. The inhibition of DNA ligase probably also contributes to the inhibition of DNA synthesis and, thus, to the cytotoxic effect of Ara-C and may explain the smaller size of DNA fragments observed following Ara-C treatment. The variations in each critical determinant observed in these three cell lines increase the complexity and plurality of the mechanisms of Ara-C action.

Modifications of hemato-biological parameters in pregnant women in a migrating population in northern Cameroon: prevalence of anemia, iron and folates deficiencies.

The wholesale displacement of a population can have nutritional consequences for the migrants. With this in mind, the prevalences of anemia and of iron and folic acid deficiencies were studied in a group of 90 pregnant women living in northeast Benoue, an area situated in northern Cameroon where a development project was initiated in 1973. This project aimed at moving a population from the extreme northern highlands to the fertile valley of the Benoue. The following hemato-biological parameters were measured: hemoglobin, hematocrit, mean cell hemoglobin concentration, plasma iron, transferrin saturation, serum concentrations of folates, prealbumin, transferrin, protides and their fractions. The investigation showed that anemia, as well as iron and folic acid deficiencies, were rare when using World Health Organization criteria. The anemia prevalence, judged on a hemoglobin level of less than 11 g per 100 ml, is 8%, iron deficiency prevalence is 10% (plasma iron level below 50 micrograms per 100 ml), and folic acid deficiency prevalence is 3% (serum folic acid level below 3 ng per ml). However, 40% of the pregnant women had a level of transferrin saturation below 15%. In non deficient subjects, we observed a decrease between the first and second trimesters of pregnancy in hemato-biological parameters linked to anemia or to nutritional status (hemoglobin, hematocrit, plasma iron, transferrin saturation, prealbumin). The nutritional conditions in the area appeared sufficient to prevent deficiencies which are frequently observed in pregnant women in Africa.

[Effect of ranitidine on secretion of gastric intrinsic factor and absorption of vitamin B 12]. / Effet de la ranitidine sur la sécrétion de facteur intrinsèque gastrique et sur l'absorption de la vitamine B12.

The effects of ranitidine, a new potent histamine H2-receptor antagonist, on gastric intrinsic factor (IF) secretion and protein-bound cobalamin absorption were evaluated in 6 patients with duodenal ulcer, before, during and after discontinuation of ranitidine therapy. Oral ranitidine (150 mg twice a day) resulted in a non significant decrease of IF concentration and IF output but was responsible for malabsorption of protein-bound cobalamin. This malabsorption was reversible upon discontinuation of ranitidine. These results indicate that occurrence of cobalamin deficiency cannot be excluded during long-term ranitidine treatment and emphasize the need for careful follow-up in these patients.

[Functional, morphological and biochemical study of the jejunal mucosa in cryptogenetic colitis]. / Etude fonctionnelle, morphologique et biochimique de la muqueuse jéjunale dans les colites cryptogénétiques.

The function of the jejunum has been assessed in patients with ulcerative colitis (n = 23) and Crohn's disease of the colon (n = 20) by measurement of serum folate levels, oral folic acid and D-xylose absorption. Forty-six normal subjects served as controls. The mean serum folate level was 4.5 +/- 2.0 ng/ml in patients with the disease and 7.8 +/- 1.7 ng/ml in controls (p less than 0.001) and was similarly decreased in both ulcerative colitis and Crohn's disease patients. It was lower in patients under sulphasalazine therapy (n = 15) than in those untreated: 3.5 +/- 1.5 vs. 4.8 +/- 2.1 ng/ml (p less than 0.05). Serum folate correlated with disease activity in the latter only. The peak serum folate obtained during the oral absorption test was decreased in patients: 38.9 +/- 12.9 vs. 60.8 +/- 19.3 ng/ml in controls (p less than 0.001); this decrease was similar in ulcerative colitis and Crohn's disease, in treated and untreated patients and was independent of disease activity. Basal serum folate did not correlate with peak serum folate in any patient group. D-xylose absorption was normal in every case. Jejunal biopsies were performed in 23 patients, 13 of whom had folic acid malabsorption (13 with ulcerative colitis, 10 with Crohn's disease of the colon). The crypt height/villus height ratio was abnormal (greater than 0.6) in only 2 patients and borderline in 9 others. The fragility of enterocyte brush-borders and lysosomes, as assessed by biochemical methods, was normal in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Myasthenia and pernicious anemia or Biermer's (author's transl)]. / Myasthénie et anémie pernicieuse dite de Biermer.

The association of myasthenia and Biermer's anemia is very rarely reported. In a series of 138 cases of myasthenia, this association was found in only one patient, in whom the anemia developed 19 years after the discovery of a calcified thymoma and 13 years after the appearance of the first signs of myasthenia. This led the authors to conduct a prospective study for the presence of intrinsic antifactor antibodies. A total of 81 patients (20 men and 61 women) with myasthenia were studied. The myasthenia had appeared after 35 years of age in 40 patients and 19 had a thymoma. The results of the study for the antibodies was positive in 3 women, as was the test of inhibition of leucocyte migration, but none of them had anemia, vitamin B12 malabsorption, achlorhydria, or gastric atrophy. The discovery of these immunological disorders raises the problem of their significance ; two hypotheses can be discussed : pre-Biermer state or immunological disturbance without pathogenetic significance. The problem can probably only be resolved by studying these antibody levels in a very much larger number of patients with myasthenia.

[Hemolysis and schizocytosis, malabsorption and the "folate trap": unusual semiological peculiarities associated with vitamin B12 deficiency]. / Hémolyse et schizocytose, malabsorption et "piège à folates": à propos de particularités sémiologiques mal connues des carences en vitamine B12.

INTRODUCTION: Hemolysis and red cell fragmentation accompanying vitamin B12 deficiency may misdirect the diagnosis. Signs of malabsorption and abnormalities related to folic acid metabolism characterized by discrepancies between folic acid normal serum levels and erythrocytic folic acid levels may also exist. EXEGESIS: We report the occurrence of hemolysis and red cell fragmentation mimicking microangiopathic hemolytic anemia, malabsorption and folic acid deficiency in the course of vitamin B12 deficiency. Appropriate replacement therapy corrected all abnormalities. CONCLUSION: An association between hemolysis, malabsorption and folic acid deficiency should lead physicians to search for signs of vitamin B12 deficiency.

[Homocystinuria in adulthood]. / L'homocystinurie à l'âge adulte.

Homocystinuria is a genetically determined inborn error of the methionine amino acid pathway characterized by increased plasma homocysteine. In its major form, homocystinuria, is due to cystathionine beta synthase deficiency. Treatment of these adulthood patients lead physicians to call up on the skilled advices of pediatricians. But prevention and treatment of age related vascular and osteoporotic complications are still to be evaluated.

[Plasma, red cell, and cerebrospinal fluid folate in Alzheimer's disease]. / Variations des folates plasmatiques, intraérythrocytaires et intrarachidiens, dans la démence sénile de type Alzheimer.

This study compares plasma, red cell, and cerebrospinal fluid (CSF) folate levels in subjects with mild or moderate Alzheimer's disease (AD) of senile onset and in non-demented control subjects. Twelve subjects with mild or moderate (Folstein's Mini-Mental-State-MMS--between 10 and 23) AD (DSM3 R criteria) and 12 control subjects without dementia and with MMS above 23 were included. To avoid any change in plasma folate levels due to dehydration, all dehydrated subjects were excluded. Were also excluded all subjects obviously suffering from malnutrition or alcoholism, or taking drugs likely to interfere with folate metabolism. Changes in folate levels due to posture or prolonged venous occlusion were carefully avoided. Patients with AD were 5 males and 7 females aged (Mean +/- SD) 80.2 +/- 5.7 years, MMS 14.8 +/- 2.6; controls were 7 males and 5 females aged 78.9 +/- 7.2 y, MMS 28.3 +/- 1.5. The two groups were not statistically different for these variables, except for the MMS. Plasma folate levels were lower (p < 0.006) in patients with AD (4.5 +/- 1.5 micrograms/l) compared with controls (7 +/- 2.2 micrograms/l). Red cell folate levels were lower (p < 0.007) in patients with AD (183.7 +/- 91.1 micrograms/l) compared with controls (300.4 +/- 96.1 micrograms/l). CSF folate levels were lower in AD (18.9 +/- 9.7 micrograms/l) than in controls (21.9 +/- 8.2 micrograms/l) but the difference was not statistically significant (p > 0.05). Our results indicate poorer nutrition in patients with AD.

[Folate deficiency in medical intensive care: incidence, predictive factors and consequences. Results of a prospective study with 105 patients]. / La carence en folates en réanimation médicale: fréquence, facteurs prédictifs et conséquences. Résultats d'une étude prospective chez 105 malades.

Among 105 patients admitted to a medical intensive care unit over a five-month period, 53 per cent had a fall in serum folate concentration (less than 5 ng/ml), and 19 per cent had a concomitant fall in erythrocyte folate concentration (less than 170 ng/ml). Acute folate deficiency with severe haematological changes was observed in 2 patients. Apart from these 2 cases, the usual haematological parameters were not significantly different in patients with or without folate deficiency. On admission, there was a significant correlation between folate status, severity index and serum albumin and transferrin, all variables which reflect the patient's nutritional status. Patients with infection and fever, and those who have recently been operated upon are at a higher risk of folate deficiency. These findings suggest that patients admitted to a medical intensive care unit should receive an early supplement of folic acid.