Test utilization for the diagnosis of vitamin B12 and folate deficiency in local clinics in Korea

The Utilization of Serum Folate and Homocysteine Tests and the Prevalence of Folate Deficiency in Reproductive-Age Korean Women during the COVID-19 Pandemic

We investigated the prevalence of folate deficiency and associated factors in a large population of Korean women of reproductive age during the COVID-19 pandemic. We utilized different cut-offs and evaluated age, year of testing, geographical region, and the utilization of serum homocysteine levels. Out of the 27,758 women evaluated, the overall prevalence of folate deficiency was 12.5% (<4 ng/mL, metabolic indicator) and 5.4% (<3 ng/mL, hematologic indicator). Homocysteine testing was observed in 8.4% of women, with 2.7% having elevated homocysteine levels (>15.4 µmol/L). According to our multiple logistic regression analysis, younger women, particularly those aged 20 to 24 years, tested in 2020, and from Jeolla province, Gyeongsang province, and Jeju Island, were identified as being more prone to folate deficiency. Receiver operating characteristic curve analysis demonstrated that a cut-off of >8.4 µmol/L provided the most accurate definition of folate deficiency with serum folate levels <4 ng/mL, while a cut-off of >8.8 µmol/L best defined folate deficiency with serum folate levels <3 ng/mL, with both cut-offs being lower than 15.4 µmol/L. Our study emphasizes the prevalence of folate deficiency, associated factors, and the role of homocysteine in planning nutritional support programs in Korea.

Diagnostic value of oral "beefy red" patch combined with fingertip blood mean corpuscular volume in vitamin B12 deficiency

OBJECTIVES

To investigate the diagnostic value of accessible fingertip mean corpuscular volume (MCV) combined with a visible "beefy red" patch in the diagnosis of vitamin B12 (VB12) deficiency in local clinics and hospitals without in-house clinical laboratories, especially in remote areas.

MATERIALS AND METHODS

The medical history data of patients complaining of oral mucosal pain at the Stomatological Hospital of Southern Medical University were reviewed. All included patients underwent fingertip blood routine examination, specific serological test (serum VB12, folic acid, iron, and ferritin), and detailed oral clinical examinations. According to the results of the serum VB12 test patients were divided into case and control groups. In diagnostic test, the diagnostic value of the "beefy red" patch and elevated MCV in VB12 deficiency was evaluated by the receiver operator characteristic curve.

RESULTS

There were more female patients than male patients in the case group (serum VB12 level < 148 pmol/L, n = 81) and control group (serum VB12 level ≥ 148 pmol/L, n = 60), mostly middle-aged and elderly patients. There were no statistical differences in gender and age between the two groups. In the case group, the number of individuals with stomach disease was 13, the number of individuals with "beefy red" patch was 78, the number of individuals with oral ulcer was 29, the number of individuals with "MCV > 100fL" and "folic acid < 15.9 nmol/L" were respectively 68 and 5. All were more than that in control group (P < 0.05). The diagnostic test, "beefy red patch" has high sensitivity (0.963) but low specificity(0.883), "MCV > 100 fL" has high specificity (0.933) but low specificity (0.815), and "MCV > 100 fL combined with beefy red patch" has maximal specificity (0.950), and area under the curve (0.949).

CONCLUSIONS

Visible oral "beefy red" patch combined with accessible fingertip blood MCV could improve the rate of diagnosis in VB12 deficiency, especially in the elderly in local clinics and hospitals without in-house clinical laboratories in China, which is conducive to early disease detection and treatment.

Test utilization for the diagnosis of vitamin B12 and folate deficiency in local clinics in Korea

Background

Current guidelines pertaining to diagnosing macrocytic anemia in association with vitamin B12 and folate deficiency recommend that vitamin B12, folate, homocysteine, and methylmalonic acid assays should be assessed concurrently due to their close relationship in metabolism. We aimed to investigate the completion of these assays in local clinics and hospitals without in‐house clinical laboratories in Korea.

Methods

We retrospectively reviewed data from the laboratory information system between September 25, 2017, and June 30, 2019, to investigate usage rates of vitamin B12, folate, homocysteine, and methylmalonic acid assays in patients with macrocytic anemia.

Results

During the study period, 14 894 Korean adults among 109 524 (13.6%) total hemoglobin‐tested subjects underwent concurrent erythrocyte mean corpuscular volume (MCV) tests. Among these 14,894 adults, 265 (1.2%) from 94 local clinics or hospitals without in‐house clinical laboratories in Korea had macrocytic anemia. Furthermore, among these 265 adults, only one woman underwent serum vitamin B12 and folate assay and one man underwent serum homocysteine testing during the study period. No patients among the 265 individuals with macrocytic anemia received erythrocyte folate or methylmalonic acid testing (with either serum, plasma, random urine, or 24‐hour collected urine).

Conclusions

The results of this study provide basic information regarding utilization rates of assays in association with vitamin B12 and folate deficiency. Making more data available is expected to improve rates of testing in patients with macrocytic anemia in local clinics and hospitals without in‐house clinical laboratories in Korea.