Is there a role for folate determinations in current clinical practice in the USA?

Our objectives were to determine the likelihood of true folate deficiency among patients tested for this disorder, to identify whether there were differences between the clinical indications for folate testing in folate-normal and folate-deficient patients and to assess the impact of a diagnosis of folate deficiency on patient management. The results of all blood samples analyzed for serum and erythrocyte folate levels during the year 2001 at the Cleveland Clinic Foundation were retrieved. Folate deficient patients were identified and their medical charts were reviewed to determine the indications, patient characteristics, and impact of this diagnosis on patient management. For comparison, medical chart review was also conducted on a control group composed of an equal number of randomly selected patients with normal serum folate values. A total of 6024 (4689 serum and 1335 erythrocyte) samples from 4985 patients were collected. In the study, 77 (1.6%) of the serum folate levels, from 74 patients, were identified as low. When compared with the control group, patients with low serum folate levels had lower hemoglobin and a greater red cell distribution width. Mean corpuscular volume, however, did not differ between the two groups. No significant differences in the clinical indications for serum folate level determinations could be identified. Only 39 of the 74 patients with low serum folate levels were given folate replacement, representing only 0.9% of the clinically suspected and tested patients. We conclude that determination of serum folate level infrequently led to appropriate folate replacement therapy. Moreover, even when suspected, true folic acid deficiency is rare and clinical indications are not helpful in diagnosis.

Folate and cobalamin deficiencies and hyperhomocysteinemia in Bangladesh

BACKGROUND

Indian Asian men residing in the United Kingdom have a higher prevalence of hyperhomocysteinemia than do their European counterparts. This has been largely attributed to dietary deficiencies in cobalamin associated with vegetarianism among these Indian Asians.

OBJECTIVE

We aimed to ascertain the prevalence of folate and cobalamin deficiencies and hyperhomocysteinemia in Bangladesh.

DESIGN

Plasma concentrations of homocysteine, folate, and cobalamin and urinary concentrations of creatinine were assessed in 1650 adults in Bangladesh.

RESULTS

The prevalence of hyperhomocysteinemia (men: >11.4 micromol/L; women: >10.4 micromol/L) was markedly (P < 0.0001) greater among men (63%; x +/- SD: 15.3 +/- 9.5 micromol/L) than among women (26%; 9.5 +/- 4.7 micromol/L). Folate was lower (9.8 +/- 6.5 and 12.3 +/- 7.6 nmol/L, respectively), whereas cobalamin was higher (281 +/- 115 and 256 +/- 118 pmol/L, respectively) (P < 0.0001 for both) among men than among women. Folate explained 15% and cobalamin explained 5% of the variation in homocysteine concentrations. For men, folate (P = 0.005) and cobalamin (P = 0.03) were positively correlated with urinary creatinine. Smoking (P < 0.0003) and betelnut use (P < 0.0002) were independent negative predictors of folate.

CONCLUSIONS

Bangladeshi men have a high prevalence of hyperhomocysteinemia, which is more closely associated with folate than with cobalamin, although other factors, eg, smoking and betelnut use, may also contribute to its cause. The positive correlations between urinary creatinine and plasma folate and cobalamin were unanticipated and could suggest that, in marginal nutrition, these vitamins may be limiting for creatine biosynthesis.

[Iron, folic acid and vitamin B12 deficiencies related to anemia in adolescents from a region with a high incidence of congenital malformations in Venezuela]

Since in recent years for certain age groups, the main cause of anemia is not iron deficiency, we intended to study the effect of iron, folic acid and vitamin B12 deficiencies on anemia prevalence in adolescents from Venezuela. One hundred adolescents aged between 12 and 19 years participated in the study. Each subject was interviewed about antecedents and habits and a physical examination and a 24-hour food recall questionnaire were performed. From a blood sample, hemoglobin and hematocrit concentrations were determined and serum was separated for quantification of ferritin, folic acid and vitamin B12 concentrations. Prevalence of anemia was 78% and for iron, folic acid and vitamin B12 deficiencies were 34.66, 90.9 and 18.18%, respectively. From anemic cases, 35.89% presented iron deficiency, while 91.02% presented folic acid deficiency. Only 19.23% of adolescents with anemia presented also vitamin B12 deficiency, but all the cases with vitamin B12 deficiency, were anemic. Simultaneous iron and folic acid deficiencies affected 30.76% of anemic cases. The high prevalence of deficiencies found in this work could be explained by insufficient intake and inadequate food habits. The prevalence of anemia was associated to folic acid deficiency rather than to iron deficiency, due to the high prevalence of folic acid deficiency. The high prevalence of nutritional deficiencies found in this work, especially regarding folic acid deficiency, require immediate interventions.

Is it Alzheimer's disease or something else? 10 disorders that may feature impaired memory and cognition

Patients who have the classic combination of progressive memory loss and problems retrieving stored knowledge that is characteristic of Alzheimer's disease may actually have another, treatable disorder. In these cases, appropriate evaluation can reveal the true diagnosis and guide therapy to stabilize or improve thinking and avert other complications. In this article, Dr Barrett explores 10 conditions that may be mistaken for Alzheimer's disease.

Dietary habits and nutritional status of renal transplant patients

BACKGROUND

Although dialysis nutritional problems are well described, nutritional problems after renal transplantation (RT) have received little attention.

METHODS

Body composition as assessed by dual-energy x-ray absorptiometry in 115 stable patients 6.6 +/- 5.9 years after RT and repeated 2.9 years later, when a 3-day dietary history was obtained in 79 patients.

RESULTS

Patients diet was generally sufficient, but was characterized by a high fat intake and deficiencies in folic acid, vitamin D, thiamine, iodine, selenium, and iron intake. Patients were often overweight, and at any given weight had a 4% to 5% higher proportion of body fat than normal. Loss of fat weight was related to high initial fat weight, long RT duration, and low plasma bicarbonate, but not steroid dose.

CONCLUSION

Dietary advice concerning fat intake is indicated for RT patients, and nutritional supplements with folic acid and vitamin D are generally required. Their main nutritional problem is obesity. This is not adequately measured by body mass index, which should be supplemented by dual-energy x-ray absorptiometry. Attention should be paid to the prevention of acidosis.

Relationship of homocysteine, folic acid and vitamin B12 with depression in a middle-aged community sample

BACKGROUND

Case control studies have supported a relationship between low folic acid and vitamin B112 and high homocysteine levels as possible predictors of depression. The results from epidemiological studies are mixed and largely from elderly populations.

METHOD

A random subsample of 412 persons aged 60-64 years from a larger community sample underwent psychiatric and physical assessments, and brain MRI scans. Subjects were assessed using the PRIME-MD Patient Health Questionnaire for syndromal depression and severity of depressive symptoms. Blood measures included serum folic acid, vitamin B12, homocysteine and creatinine levels, and total antioxidant capacity. MRI scans were quantified for brain atrophy, subcortical atrophy, and periventricular and deep white-matter hyperintensity on T2-weighted imaging.

RESULTS

Being in the lowest quartile of homocysteine was associated with fewer depressive symptoms, after adjusting for sex, physical health, smoking, creatinine, folic acid and B12 levels. Being in the lowest quartile of folic acid was associated with increased depressive symptoms, after adjusting for confounding factors, but adjustment for homocysteine reduced the incidence rate ratio for folic acid to a marginal level. Vitamin B12 levels did not have a significant association with depressive symptoms. While white-matter hyperintensities had significant correlations with both homocysteine and depressive symptoms, the brain measures and total antioxidant capacity did not emerge as significant mediating variables.

CONCLUSIONS

Low folic acid and high homocysteine, but not low vitamin B12 levels, are correlates of depressive symptoms in community-dwelling middle-aged individuals. The effects of folic acid and homocysteine are overlapping but distinct.

Cerebral folate deficiency: life-changing supplementation with folinic acid

Cerebral folate deficiency is characterized by low cerebrospinal fluid (CSF) concentrations of 5-methyltetrahydrofolate and a broad spectrum of clinical signs and symptoms. A patient with progressive spasticity, gait disturbance, speech difficulties, initially diagnosed as a recessive spastic paraplegia recovered on folinic acid (15-30 mg/day) and her 5-methyltetrahydrofolate in CSF normalized. This report demonstrates the importance of CSF investigation in the diagnosis of cerebral folate deficiency and efficiency of folinic acid (5-formyltetrahydrofolate) supplementation.

[Vitamin B12, folic acid and mental function in the elderly]

Elderly people is a vulnerable population group to specific nutrient deficiencies as vitamin B12 and folic acid, which are closely related to mental functions deterioration, especially of cognitive functions. This study was aimed to measure B12 vitamin and folic acid indicators and to establish relationships to mental function. 53 elderly, older than 60 years, living in a geriatric home were assessed. The dietary intake was evaluated by the direct weighed method, serum B12 vitamin and folic acid by radioimmunoanalysis and mental function by Foltein's mini-mental test. Dietary intake for Vit B12 was adequate and deficient for folic acid while serum levels were within normal range. Vitamin B12 levels were at marginal or deficiency values in 26,4% of the elderly and folic acid deficiency was present in 43.4%. 49% of the elderly had mental function alterations and B12 vitamin levels were significantly lower in this group. A positive association between age and mental function (elderly below 80 years had lower risk of mental impairment) and between serum B12 and mental function were found. Elderly were at risk of deficiency for both vitamins and age and mental function were associated to this risk. Further evaluation including other nutrients should be performed.

[Pancytopenia, haemolytic anaemia, schistocytes: a frequent pathology mimicking a rare and serious pathology]

A 83 years old woman presents to our hospital with fatigue and dyspnea since 2 weeks, followed by a painless icterus. On laboratory we discover a pancytopenia with severe haemolytic anaemia, thrombopenia and schistocytosis. This association suggest a thrombotic microangiopathy. In the presence of macrocytes, hypersegmented neutrophils and a low reticulocytes count, a vitamin screening was performed witch leads to the discovery of a vitamin B12 and folic acid deficiency. After initiation of a vitamin therapy we observe a reticulocytic crisis and thereafter the normalisation of the haematological parameters.

Cerebral folate deficiency

Cerebral folate deficiency (CFD) can be defined as any neurological syndrome associated with low cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF), the active folate metabolite, in the presence of normal folate metabolism outside the nervous system. CFD could result from either disturbed folate transport or from increased folate turnover within the central nervous system (CNS). We report on a novel neurometabolic syndrome in 20 children, which we term 'idiopathic CFD'. Typical features became manifest from the age of 4 months, starting with marked unrest, irritability, and sleep disturbances followed by psychomotor retardation, cerebellar ataxia, spastic paraplegia, and dyskinesia; epilepsy developed in about one third of the children. Most children showed deceleration ofhead growth from the age of 4 to 6 months. Visual disturbances began to develop around the age of 3 years and progressive sensorineural hearing loss started from the age of 6 years. Neuroimaging showed atrophy of frontotemporal regions and periventricular demyelination in seven children, slowly progressive supra- and infratentorial atrophy in three children, and normal findings in the remainder. Because active folate transport to the CNS occurs through receptor-mediated folate receptor protein 1 (FR1) endocytosis, DNA sequencing of the FR1 gene was performed and found to be normal. However, CSF protein analysis revealed a non-functional FR1 protein, suspected to result from either post-translational defects of FR1 protein N-glycosylation, the presence of folate antagonists with irreversible binding, or autoantibodies blocking the folate binding site of FR1. Oral treatment with 5-formyltetrahydrofolate (folinic acid) should be started in low doses at 0.5-1mg/kg/day, but in some patients higher daily doses of folinic acid at 2-3 mg/kg/day are required to normalize CSF 5MTHF values. This proposed treatment protocol resulted in a favourable clinical response in patients identified before the age of six years while partial recovery with poorer outcome was found beyond the age of 6 years. Careful clinical and EEG monitoring should be performed 1, 3, and 6 months after the beginning of treatment. After four to six months of folinic acid treatment, CSF analysis should be repeated in order to prevent over- or under-dosage of folinic acid. Secondary forms of CFD have been recognized during chronic use of antifolate and anticonvulsant drugs and in various known conditions such as Rett syndrome, Aicardi-Goutières syndrome, 3-phosphoglycerate dehydrogenase deficiency, dihydropteridine reductase deficiency, aromatic amino acid decarboxylase deficiency, and Kearns-Sayre syndrome. The pathogenic link between these underlying specific disease entities and the observed secondary CFD has not been resolved.

Second trimester folate status and preterm birth

OBJECTIVE

The purpose of this study was to show that maternal folate status during pregnancy may be related to preterm birth.

STUDY DESIGN

Women were recruited at 24 to 29 weeks' gestation from 1995 to 2000 into the Pregnancy, Infection, and Nutrition Study. Those who completed an interview and a food frequency questionnaire, or provided a blood sample for radioassay of serum (n = 2026) and red blood cell (n = 1034) folate were included.

RESULTS

Mean daily dietary folate intake was 463 microg (SD +/- 248). Intake </=500 microg was associated with increased preterm delivery (RR = 1.8, 95% CI 1.4-2.6) controlling for total energy intake. Serum folate levels <16.3 ng/mL and red blood cell folate levels </=626.6 ng/mL yielded adjusted risk ratios of 1.8 (95% CI 1.3-2.5) and 1.7 (95% CI 1.1-2.6), respectively. Patterns were similar for spontaneous and overall preterm birth.

CONCLUSION

These results support the hypothesis that low folate levels during the second trimester of pregnancy are associated with an increased risk of preterm birth.

Destructive, Granulating Lesion in the Temporal Bone After Elevated Plasma Homocysteine

OBJECTIVE

This is a presentation of a seemingly new otolaryngologic disease.

SETTING

This study was conducted at a tertiary referral center.

CASE REPORT

A 38-year-old healthy man developed left-sided sudden deafness with vertigo and temporary left facial palsy. A granulating and destructive lesion in the left temporal bone was discovered; repeated histologic examination only showed simple granulation tissue. After 6 months, a part of the bony cochlea was extruded. With approximately 8 months' delay and after the patient had had postoperative lung embolism, plasma homocysteine was found to be significantly elevated, a condition known as an independent risk factor for thromboembolic lesions. In the acquired form, it is most often caused by nutritional deficiency of vitamin B cofactors. Accordingly, the patient was treated with folic acid, which rapidly normalized plasma homocysteine. Subsequently, the granulation tissue in the temporal bone gradually disappeared, clinically and radiologically, and the lesion healed, obviously without cochlea function.

CONCLUSIONS

Thromboembolic lesion in the left temporal bone, probably in the thin end artery a. labyrintina, i.e., an avascular osteonecrosis. During the latest years, an association between avascular osteonecrosis (most often in the hip) and conditions with increased risk of thrombosis such as hyperhomocystinemia has been established but, to the best of our knowledge, it is never with a lesion in the temporal bone.

Levels of alpha-fetoprotein during pregnancy and early infancy in normal and disease states

Alpha-fetoprotein (AFP) was 1 of the first serum protein markers to serve in the dual capacities of tumor marker and fetal defect marker, ie, an oncofetal protein, in the clinical laboratory. Although the serum-marker capacity of AFP has long been used, less is known of the fluid compartments of this oncofetal protein during fetal and perinatal development. In this review, the biologic activities of AFP are discussed in light of its presence in the various biologic fluid compartments: fetal serum, amniotic fluid, cord blood, urine, and maternal serum. AFP concentrations within the biologic fluids are considered in the context of gestational age, sex, body weight, and anatomic location. Discussion follows concerning the relationships and roles of AFP in various developmental disorders such as hypothyroidism, folate deficiencies, autoimmune disorders, acquired immunodeficiency disorder (AIDS), congenital heart defects, cystic fibrosis, preeclampsia/hypertension, and platelet aggregation disorders. Based on its presence in so many types of birth defects, malformations, and congenital anomalies, AFP can be seen to serve as a form of molecular "duct tape" during pregnancy and postnatal development.

Strategies for the Laboratory Diagnosis of Some Common Causes of Anaemia in Elderly Patients

Anaemia is a common medical problem in elderly patients and is associated with an increased mortality and morbidity risk and a reduced quality of life. It is not known at which exact haemoglobin level investigations should be initiated in order to optimize the diagnostic efficacy. Serum ferritin determination remains the most accurate laboratory test for the diagnosis of iron deficiency anaemia and its differential diagnosis with the anaemia of chronic disease. The introduction of the metabolites methylmalonic acid and homocysteine has made it possible to diagnose vitamin B(12) and folate deficiencies at an early subclinical stage, even without neurological and haematological symptoms, but the clinical importance of this 'biochemical' diagnosis is unclear. Other causes of anaemia, such as myelodysplastic syndromes and chronic renal insufficiency, will become more and more common in the elderly because of the ageing of the population. Although erythropoietin analysis has no clear diagnostic value at the moment, it has become more and more obvious that its therapeutic importance in elderly patients with chronic anaemia is increasing. A substantial number of patients have an unexplained anaemia. Whether this is disease related, or may be attributed to an age-related anaemia, is still a matter of debate, but it is advisable to perform an extensive laboratory, cytogenetic, and morphological investigation before one should assess the anaemia as unexplained.

Red cell or serum folate? Results from the National Pathology Alliance benchmarking review

AIMS

The National Pathology Alliance benchmarking review has completed five years of data collection and analysis of the workload and organisation of haematology laboratories in the UK. This study analyses variation in practice in how laboratories respond to a request to determine whether or not a patient has folate deficiency.

METHODS

A three year analysis of workload data on the number of serum/plasma folate and red cell folate assays performed on an annual basis for the period 1 April 1999 to 31 March 2002.

RESULTS

Three diagnostic testing strategies were found, namely: serum/plasma folate only, red cell folate only, and both serum/plasma folate and red cell folate.

CONCLUSION

Evidence from the literature indicates that serum folate measurements provide equivalent information to red cell folate measurements when attempting to determine whether folate deficiency is present. There seems to be no basis for the routine testing of all samples for serum/plasma folate and a red cell folate.

The aetiology of severe anaemia among antenatal patients of the Port Moresby General Hospital

Between October 1998 and September 2000, 111 consecutive pregnant patients admitted to the Port Moresby General Hospital antenatal ward with a haemoglobin level of 6 g/dl or less were studied. The main causes of the severe anaemia were as follows: iron deficiency on its own or in combination with another factor 66%--iron deficiency on its own 43% and combined folate and iron deficiency 23%--and folate deficiency 18%. Malaria was a contributory factor in 13 patients (12%). A combination of blood film, bone marrow study, serum assays of ferritin, folate and vitamin B12, and mean corpuscular volume (MCV) was used to determine the cause of the anaemia. Ferritin levels on their own poorly correlated with the presence of iron in the bone marrow. A low MCV correlated well with iron deficiency anaemia while a high MCV was associated with folic acid deficiency. It would seem therefore that while a bone marrow study is mandatory to reach a definitive diagnosis of severe anaemia, MCV, in conjunction with the red cell morphology on blood film, would be a good marker for iron and folic acid deficiency anaemia, especially as we do not have serum assays readily available for folate, ferritin and vitamin B12 in Papua New Guinea.

Homocysteine and methylmalonic acid in diagnosis and risk assessment from infancy to adolescence

The concentration of total homocysteine (tHcy) in serum and plasma is elevated in both folate and cobalamin deficiencies, whereas methylmalonic acid (MMA) in serum, plasma, or urine is a specific marker of cobalamin function. The combined measurement of both metabolites is useful for the diagnosis and follow-up of these deficiency states. In addition, tHcy is elevated under various pathologic states (eg, renal failure), and hyperhomocysteinemia is associated with an increased risk of cardiovascular disease, cognitive dysfunction, and adverse pregnancy outcomes. The diagnostic utility of tHcy and MMA concentrations as markers of folate and cobalamin deficiencies in healthy and diseased children has been documented. This article briefly summarizes the biochemical background of tHcy and MMA and the associations of tHcy and MMA with various disease states and focuses on novel data obtained in infants, children, and adolescents, with emphasis on cobalamin status in infants. The utility of tHcy and MMA as indicators of cobalamin and folate deficiencies in adults can be extended to infants and older children. Furthermore, as in adults, tHcy is related to unhealthy lifestyle factors and is a risk factor for vascular disease. High MMA concentrations in newborns, occasionally denoted as benign methylmalonic aciduria, may reflect impaired cobalamin function.