Lack of clinical utility of folate levels in the evaluation of macrocytosis or anemia

Robinson, Andrew; Mladenovic, Jeanette

doi:10.1016/s0002-9343(00)00670-7

Cited by 34 publications

(52 citation statements)

References 11 publications

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“…25 In a study of indigent patients, Joelson et al found that 4.8% had low red cell folic acid levels in 1997, and that this prevalence fell to 0.6% in 2004 following the introduction of fortified foods. 26 The prefortification estimates are clearly higher than we observed, whereas our numbers were similar to those of Joelson et al In fact, excluding those patients who had testing for altered cognition, 0.6% of our remaining patients had low folic acid levels.…”

Section: Discussionmentioning

confidence: 99%

Clinical Utility of Folic Acid Testing for Patients with Anemia or Dementia

2008

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BACKGROUND: Serum folic acid tests are routinely ordered by physicians for evaluating anemia and sometimes ordered for evaluating dementia and altered mental status. OBJECTIVE:To determine the utility of routine folic acid testing for patients with anemia or dementia/ altered mental status in the era of folic acid fortification. DESIGN:Retrospective analysis of consecutive folic acid tests performed on adults over a 4-month period; chart review of patients without anemia. MEASUREMENTS AND MAIN RESULTS:Serum folic acid level, mean corpuscular volume (MCV), and hematocrit. We reviewed 1,007 folic acid tests performed on 980 patients. The average age was 63.8 years, and 62% of the tests were from outpatient facilities. Only 4 (0.4%) patients had folic acid levels <3 ng/mL, while 10 (1%) patients had levels of 3-4 ng/mL (borderline). Thirty-five percent of the folic acid tests were performed on patients who were not anemic; most of these were ordered to evaluate dementia or altered mental status and folic acid level was normal in all these patients. Only 7% of the patients tested had a macrocytic anemia; these patients were more likely than those without macrocytic anemia to have low folic acid levels (2.8% vs 0.4%, p<.03).CONCLUSION: Low serum folic acid levels were rarely detected in a series of patients being evaluated for anemia, dementia, or altered mental status. The test should be reserved for patients with macrocytic anemia and those at high risk for folic acid deficiency.KEY WORDS : folic acid, anemia, dementia.

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Section: Discussionmentioning

confidence: 99%

Clinical Utility of Folic Acid Testing for Patients with Anemia or Dementia

2008

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“…Blood vitamin measurements are established and simple to perform, but are increasingly considered to be neither sufficiently sensitive nor specific (2,(122)(123)(124)(125). There is limited consensus on reference limits and desirable concentrations (108,109 ).…”

Section: Comparison Of Blood Tests No Single Blood Test Used For Assmentioning

confidence: 99%

Facts and Recommendations about Total Homocysteine Determinations: An Expert Opinion

et al. 2004

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Background: Measurement of plasma total homocysteine has become common as new methods have been introduced. A wide range of disorders are associated with increased concentrations of total homocysteine. The purpose of this review is to provide an international expert opinion on the practical aspects of total homocysteine determinations in clinical practice and in the research setting and on the relevance of total homocysteine measurements as diagnostic or screening tests in several target populations. Methods: Published data available on Medline were used as the basis for the recommendations. Drafts of the recommendations were critically discussed at meetings over a period of 3 years. Outcome: This review is divided into two sections: (a) determination of homocysteine (methods and their performance, sample collection and handling, biological determinants, reference intervals, within-person variability, and methionine loading test); and (b) risk assessment and disease diagnosis (homocystinuria, folate and cobalamin deficiencies, cardiovascular disease, renal failure, psychiatric disorders and cognitive impairment, pregnancy complications and birth defects, and screening of elderly and newborns). Each of these subsections concludes with a separate series of recommendations to assist the clinician and the research scientist in making informed decisions. The review concludes with a list of unresolved questions. © 2004 American Association for Clinical ChemistryIncreased plasma total homocysteine (tHcy) 7 is a sensitive marker of folate and cobalamin (vitamin B 12 ) deficiency (1, 2 ) and an independent risk factor for cardiovascular disease (CVD) (3,4 ). Plasma tHcy concentrations are also related to birth defects (5 ), pregnancy complications (6 ), psychiatric disorders (7 ), and cognitive impairment in the elderly (8 ). The measurement of tHcy in the clinical setting is thus potentially of great importance (9 ).The introduction of tHcy assays in the mid-1980s (10, 11 ) started a new era of research on Hcy. However, it was the advent of immunoassays in the latter half of the 1990s (12, 13 ) that changed tHcy determinations from research tools to widely used clinical chemistry tests. As a result, interest in this field has increased exponentially in both routine diagnostics and research.Although several reviews on tHcy determinations have been published (14 -18 ), few have provided recommendations for their use in clinical practice (19 -23 ). Our aim was to review the practical aspects of tHcy determinations in clinical practice as well as in the research setting and to survey the data on tHcy in diagnostics or as screening tests in several target populations.Ideally, guidelines should be established by a multidisciplinary team including all relevant stakeholders, and the recommendations should be according to evidence-based medicine (24 ). There are not sufficient data in the Hcy field, however, to use such an approach. In particular, -32 (2004) Review 3 data from controlled clinical trials are sparse. Neverth...

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“…25,44 Complete diagnostic testing should only be performed in cases of unexplained macrocytic anemia. 45 …”

Section: Holotranscobalamin II (Holotc Ii)mentioning

confidence: 99%

“…50 Because of the inherent unreliability of measuring either serum or RBC folate, it is recommended that patients receiving treatment for vitamin B12 deficiency receive empiric folate supplementation of 400 µg/day to 1 mg/day. 27,45,51 Maintenance therapy should continue until the underlying cause of the deficiency is corrected.…”

Section: Treatment Of Vitamin B12 and Folate Deficienciesmentioning

confidence: 99%

Megaloblastic Anemia and Other Causes of Macrocytosis

Aslinia¹,

Mazza²,

Yale³

2006

Clinical Medicine & Research

284

214

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The term macrocytosis refers to a blood condition in which red blood cells (RBC) are larger than normal. Macrocytosis is reported in terms of mean corpuscular volume (MCV). Normal MCV values range from 80 to 100 femtoliters (fl) and vary by age and reference laboratory. 1 MCV is calculated according to the following formula:Macrocytosis can be identified by reviewing peripheral blood smears and/or by automated RBC indices. The peripheral blood smear is more sensitive than RBC indices for identifying early macrocytic changes because the MCV represents the mean of the distribution curve and is insensitive to the presence of small numbers of macrocytes. 2 However, compared to the peripheral blood smear, MCV may underestimate macrocytosis in over 30% of cases. 3 Although determination of the MCV by automated blood cell counter is rarely inaccurate, hyperglycemia, marked leukocytosis and cold agglutinins may result in false elevations of the MCV. [4][5][6] Moreover, partial occlusion of the instrument aperture and/or leaving the blood sample at room temperature for several hours may also result in false elevations of the MCV value. Clinical SignificanceMacrocytosis is a relatively common finding in the era of automated blood cell counters, with prevalence estimates ranging from 1.7% to 3.6%. 3,7,8 Its significance tends to be underestimated by physicians, since about 60% of patients present without associated anemia, 8 unless there are other accompanying abnormalities noted.No complications arise from macrocytosis itself as an isolated finding. However, its identification can provide important information regarding the presence of an underlying disease state. Thus, in the appropriate clinical setting, MCV values above the upper limit of normal or those that differ significantly from the patient's baseline values may require further clinical and laboratory assessment to determine the underlying cause of the macrocytosis. 9

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Lack of clinical utility of folate levels in the evaluation of macrocytosis or anemia

Cited by 34 publications

References 11 publications

Clinical Utility of Folic Acid Testing for Patients with Anemia or Dementia

Clinical Utility of Folic Acid Testing for Patients with Anemia or Dementia

Facts and Recommendations about Total Homocysteine Determinations: An Expert Opinion

Megaloblastic Anemia and Other Causes of Macrocytosis

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