Implications cliniques de la découverte d’une hypervitaminémie B12 en médecine interne

Abnormal biomarkers predict complex FAS or FADD defects missed by exome sequencing

BACKGROUND

Elevated TCRαβ+CD4-CD8- double-negative T cells (DNT) and serum biomarkers help identify FAS mutant patients with autoimmune lymphoproliferative syndrome (ALPS). However, in some patients with clinical features and biomarkers consistent with ALPS, germline or somatic FAS mutations cannot be identified on standard exon sequencing (ALPS-undetermined: ALPS-U).

OBJECTIVE

We sought to explore whether complex genetic alterations in the FAS gene escaping standard sequencing or mutations in other FAS pathway-related genes could explain these cases.

METHODS

Genetic analysis included whole FAS gene sequencing, copy number variation analysis, and sequencing of FAS cDNA and other FAS pathway-related genes. It was guided by FAS expression analysis on CD57+DNT, which can predict somatic loss of heterozygosity (sLOH).

RESULTS

Nine of 16 patients with ALPS-U lacked FAS expression on CD57+DNT predicting heterozygous "loss-of-expression" FAS mutations plus acquired somatic second hits in the FAS gene, enriched in DNT. Indeed, 7 of 9 analyzed patients carried deep intronic mutations or large deletions in the FAS gene combined with sLOH detectable in DNT; 1 patient showed a FAS exon duplication. Three patients had reduced FAS expression, and 2 of them harbored mutations in the FAS promoter, which reduced FAS expression in reporter assays. Three of the 4 ALPS-U patients with normal FAS expression carried heterozygous FADD mutations with sLOH.

CONCLUSION

A combination of serum biomarkers and DNT phenotyping is an accurate means to identify patients with ALPS who are missed by routine exome sequencing.

Exosomal MicroRNA-223, MicroRNA-146, and MicroRNA-21 Profiles and Biochemical Changes in Laryngeal Cancer

Laryngeal squamous cell carcinoma (LSCC) is one of the most aggressive cancers, and its early diagnosis is urgent. Exosomes are believed to have diagnostic significance in cancer. However, the role of serum exosomal microRNAs, miR-223, miR-146, and miR-21, and phosphatase and tensin homologue (PTEN) and hemoglobin subunit delta (HBD) mRNAs in LSCC is unclear. Exosomes were isolated from the blood serum of 10 LSCC patients and 10 healthy controls to perform scanning electron microscopy and liquid chromatography quadrupole time-of-flight mass spectrometry analyses to characterize them and to undergo reverse transcription polymerase chain reaction to identify miR-223, miR-146, miR-21, and PTEN and HBD mRNA expression phenotypes. Biochemical parameters, including serum C-reactive protein (CRP) and vitamin B12, were also obtained. Serum exosomes of 10-140 nm were isolated from LSCC and controls. Serum exosomal miR-223, miR-146, and PTEN were found to be significantly decreased (p < 0.05), in contrast to serum exosomal miRNA-21 (p < 0.01), and serum vitamin B12 and CRP (p < 0.05) were found to be significantly increased, in LSCC vs controls. Our novel data show that the combination of reduced serum exosomal miR-223, miR-146, and miR-21 profiles and biochemical alterations in CRP and vitamin B12 levels may be useful indicators of LSCC that could be validated by large studies. Our findings also suggest a possible negative regulatory effect of miR-21 on PTEN in LSCC, encouraging a more extensive investigation of its role.

Vitamin B12: For more than just the treatment of megaloblastic anemia?

Vitamin B12, or cobalamin, belongs to the group of water-soluble vitamins and is ingested through food of animal origin such as eggs, milk, red meat and poultry, fish, and shellfish. Its clinical indication is the treatment of hypovitaminosis B12 administered orally or intramuscularly in the form of hydroxocobalamin. Hypovitaminosis B12 is mainly caused by deficient dietary intake (individuals with malnutrition, vegetarians or vegans, older adults, pregnant people, individuals with alcohol use disorder); when intestinal absorption is reduced (atrophic gastritis, malabsorption syndrome, gastrointestinal surgery); and for causes associated with the intake of drugs (antacids, metformin). Hypervitaminosis B12 has been associated with renal failure; liver diseases such as cirrhosis and acute-phase hepatitis; alcohol use disorder with or without liver involvement; solid tumors of the lung, liver, esophagus, pancreas, and colorectum; and in hematological malignancies such as leukemia and bone marrow dysplasia.

High cobalamin levels as a five-year risk predictor for developing hematological cancer

BACKGROUND

A high cobalamin level has been related to non-malignant diseases (mainly liver diseases, alcoholism, and renal diseases) and cancer (hematological malignancies and solid cancers such as liver and stomach cancer). However, a previous high level of cobalamin and the implications in the possible development of cancer is still unclear. The main aim of this study was to describe if a previous high cobalamin level is a determinant in the future development of cancer in five years of follow-up. The secondary objective was to determine any differences between cancer groups.

METHODS

A retrospective study was performed. Two databases were employed. The first one included all patients who had a determination of cobalamin in a routine blood test during the year 2010 (a total of 44,166 patients). The second one showed every patient who was admitted to the reference hospital, Hospital Clinico Universitario de Valladolid, during the following five years. Finally, a number of 6710 patients was included. Both databases belong to the medical records of the Hospital Data Surveillance System and are completely validated. Multivariate logistic regression analyses were employed to evaluate the association between cobalamin levels and the appearance of cancer (total and in each subgroup). All analyses were performed using IBM SPSS 24 software (IBM Corp., Armonk, NY, USA).

RESULTS

The sample studied showed a clear association between the risk of hematological cancer and a previous high Cbl level. This relationship was higher among patients with the highest levels (over 779 pmol/L), showing almost two times more risk for development of hematological malignance within 5 years in the multivariate analysis (OR: 1.975, 95% CI: 1.056-3.697, P=0.033). Hematological malignancies were mostly diagnosed within the first three years (86.6%), showing a similar percentage in those three years. There was no association between this previous level and the development of any other type of cancer.

CONCLUSIONS

Our study shows that a high cobalamin plasma level (hypervitaminosis) is associated with the development of hematologic cancer within five years after the measurement. The clinical implication of these findings, together with the clinical suspicion, reinforces the necessity of carrying out specific screening hematological tests in patients with not justified elevated plasma cobalamin levels. New prospective and multicenter studies are necessary to validate these results.

Does High Vitamin B12 Levels Cause Proteinuria?

Aim: Cubilin receptors, which are responsible for the absorption of vitamin B12 from the intestine, are also found in the kidney and regulate protein reuptake from urine. We claimed that vitamin B12 deficiency may lead to less proteinuria as a result of increased Cubilin receptors, or higher vitamin B12 levels may cause proteinuria by down regulating the receptors. To support this hypothesis, the relationship between vitamin B12 and urine protein levels was investigated. Methods: The last two-year hospital records of patients between the ages of 18-65 were retrospectively scanned. Patients who were tested for the vitamin B12, plasma creatinine, and urine protein analyses and whose eGFR value was calculated as >60mL/min were included. Patients diagnosed with diseases that may cause proteinuria such as diabetes, malignancies, or kidney diseases were excluded. Vitamin B12 level 1000 pg/ml as hypervitaminosis. Results: Of the 31,776 patients who met the criteria, vitamin B12 deficiency was found to be 38.6% in men; 33.1% in women, and 35% in total. Rates of hypervitaminosis B12 were 1.4% in both men and women, and overall. Urinary protein was observed in 13% of all patients. A statistical significance was found between vitamin B12 levels and proteinuria. In post-hoc analysis, this statistical difference was detected between the hypervitaminosis group and the other levels. Conclusion: Vitamin B12 hypervitaminosis was found to be statistically associated with proteinuria, indicating that caution should be exercised in vitamin B12 treatment. Keywords: vitamin B12, hypervitaminosis, proteinuria

Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer

Elevated plasma vitamin B12 has been associated with solid cancers, based on a single B12 measurement. We evaluated the incidence of solid cancers following B12 measurement in patients with persistent elevated B12, compared to patients without elevated B12 and to patients with non-persistent elevated B12. The study population included patients with at least two plasma B12 measurements without already known elevated-B12-related causes. Patients with elevated plasma B12 (≥ 1000 ng/L) at first measurement (n = 344) were matched for age and sex with patients having 2 normal B12 measurements (< 1000 ng/L) (NN group, n = 344). The patients with elevated plasma B12 at first measurement were split into 2 groups, according to the presence (EE group, n = 144) or the absence (EN group, n = 200) of persistent elevated plasma B12 at second measurement. We compared the cancer-free survival during 60 months between the groups after adjustment for the other elevated-B12-related causes in a survival competing risk model. Compared to the NN group, a persistent elevated plasma B12 ≥ 1000 ng/mL was strongly associated with the occurrence of solid cancer (HR 5.90 [95% CI 2.79-12.45], p < 0.001), contrary to non-persistent plasma B12 elevation (p = 0.29). These results could help to select patients in whom the screening for solid cancers would be of interest.

Elevated holo-transcobalamin in Gaucher disease type II: A case report

Gaucher disease (GD), one of the most common lysosomal disorders, is caused by deficiency of β-glucocerebrosidase. Based on the presence and severity of neurological complications, GD is classified into types I, II (the most severe form), and III. Abnormalities in systemic markers of vitamin B₁₂ (B₁₂ ) metabolism have been reported in GD type I patients, suggesting a higher prevalence of B₁₂ deficiency in these patients. A 2-month-old male with GD type II was admitted to the hospital presenting jaundice, hepatosplenomegaly, and ichthyosis. At admission, cholestasis and ascites, abnormal liver function enzymes, prolonged prothrombin time, and high levels of B₁₂ were confirmed. Analysis of biomarkers of B₁₂ status revealed elevated B₁₂ and holo-transcobalamin (holo-TC) levels. The B₁₂ profile found in our patient is the opposite to what is described for GD type I patients. Holo-TC may increase in inflammatory states or due to liver diseases. In GD, the accumulation of glucocerebroside may be a trigger that initiates a systemic inflammatory reaction, characterized by macrophage activation. We suggest higher levels of holo-TC could be associated with a more severe (neuronopathic) GD, and be a biomarker of GD type II.

B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease

Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.

Folate and Vitamin B-12 Status Is Associated With Bone Mineral Density and Hip Strength of Postmenopausal Chinese-Singaporean Women

The role of micronutrients such as folate and vitamin B‐12 in bone quality has been widely studied with conflicting results. Ethnicity seems to play a large role on nutrient intake, as diet varies across cultures. In this study, we examined the relationships of BMD, proximal femur strength, and bone resorption with plasma folate and vitamin B‐12 in a cohort of 93 healthy postmenopausal women of Chinese‐Singaporean descent. The parameters examined were areal (aBMD) and volumetric BMD (vBMD) of the proximal femur and the third lumbar vertebra (L3), total body aBMD, proximal femur bending, compressive and impact strength indices (composite strength indices) and circulating levels of C‐telopeptide of type I collagen. Eighteen participants (19.4%) had aBMD in the osteoporotic range (osteoporosis group), 59 (63.4%) in the osteopenic range (osteopenia group), and the remaining 16 (17.2%) in the normal range (normal BMD group). Circulating folate levels were significantly higher in the normal BMD group compared with the osteoporosis group. Using linear regression analysis, we found that overall, aBMD and vBMD are positively associated with folate concentrations, whereas composite strength indices were positively associated with vitamin B‐12 concentrations. These findings support the existing literature and suggest a link between levels of circulating folate/vitamin B‐12 and BMD/bone strength in the cohort examined. Further investigation is needed to examine if individuals with inadequate circulating levels of these nutrients could decrease their risk for fragility fractures through better nutrition or vitamin supplementation. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

High Serum Vitamin B12 Levels Associated with C-Reactive Protein in Older Patients with Cancer

BACKGROUND

A Comprehensive Geriatric Assessment (CGA) has been proposed to assess prognosis and to adapt oncological care in older patients with cancer. However, few biological markers are incorporated in the CGA.

METHODS

This comparative study on older patients with cancer was realized before final therapeutic decision and during a CGA that included biological markers. Our objective study was to know if the serum vitamin B12-C-reactive protein index (BCI) can help to estimate early death and unplanned hospitalization. Associations between BCI and unplanned hospitalization or mortality were analyzed using ordered multivariate logistic regression.

FINDINGS

We included 621 older cancer adults in outpatient care with a median age of 81 years (range, 70-98 years) from September 2015 to May 2018. In this study, 5.6% of patients died within 3 months, 8.8% had unplanned hospitalization within 1 month, and 11.4% had unplanned hospitalization within 3 months. Hypercobalaminemia was present in 83 patients (13.4%), and 34 patients (5.5%) had BCI >40,000. According to the multivariate analysis, BCI was a prognostic factor of mortality within 3 months and unplanned hospitalizations at 1 and 3 months. Impaired activities of daily living (ADL) and palliative care were also risk factors for mortality within 3 months. Impaired instrumental ADL, low albumin level, and palliative care were risk factors for unplanned hospitalization at 1 month.

INTERPRETATION

BCI could be routinely added to the CGA process, as part of a pretreatment workup, in order to assess more precisely the frailties and to adapt oncological care in older patients treated for cancer.

IMPLICATIONS FOR PRACTICE

Aging comes with an increase of frailties and comorbidities. To identify frailties in older patients with cancer, this study used a Comprehensive Geriatric Assessment, which allowed for the adaptation of each treatment plan in accordance with the individual needs of the patients. However, biological characteristics were not included in this assessment. This study showed that hypercobalaminemia and vitamin B12 -C-reactive protein index may be potential markers for cancer with poor prognosis, particularly in the older population. These biological markers can be used in geriatric oncology and general medicine.

Strength of the Association of Elevated Vitamin B12 and Solid Cancers: An Adjusted Case-Control Study

The association between elevated plasma vitamin B12 (B12) level and solid cancers has been documented by two national registries. However, their design did not allow for the adjustment for other conditions associated with elevated B12. The objectives of this study were to confirm this association after the adjustment for all causes of elevated B12, and to study the variations according to the increasing B12 level, the type of cancers, and the presence of metastases. We compared 785 patients with B12 ≥ 1000 ng/L with 785 controls matched for sex and age with B12 < 1000 ng/L. Analyses were adjusted for the causes of elevated B12: myeloid blood malignancies, acute or chronic liver diseases, chronic kidney failure, autoimmune or inflammatory diseases, and excessive B12 supplementation. A B12 ≥ 1000 ng/L was associated with the presence of solid cancer without metastases (OR 1.96 [95%CI: 1.18 to 3.25]) and with metastases (OR 4.21 [95%CI: 2.67 to 6.64]) after adjustment for all elevated B12-related causes. The strength of the association rose with the increasing B12 level, in particular in cases of metastases. No association between liver cancers and elevated B12 level was found after adjustment for chronic liver diseases. In conclusion, unexplained elevated B12 levels should be examined as a possible marker of solid cancer.

Hypervitaminosis B12 - a new marker and predictor of prognostically unfavorable diseases

A high serum vitamin B12 level (hypercobalaminemia) is a underestimated anomaly. Clinically, it can be paradoxically accompanied by signs of deficiency, which are related to defects in tissue uptake of vitamin B12. The increase in the level of serum cobalamin occurs mainly in serious diseases that require early diagnosis: hemoblastosis, liver and kidney diseases, etc. This review presents data on the metabolism of vitamin B12 and the potential significance of increasing its level as a marker for the early diagnosis of these diseases.

Comparison of serum biochemical markers in patients with mesothelioma and pleural plaques versus healthy individuals exposed to environmental asbestos

Background

In this study, we aimed to compare serum biochemical markers in patients with malignant pleural mesothelioma and pleural plaques versus healthy individuals exposed to environmental asbestos.

Methods

Between September 01, 2010 and March 31, 2011, a total of 540 participants (354 males, 186 females; mean age 61.4 years; range, 35 to 89 years) were included in the study. The participants were divided into four groups as follows: (1) patients with pleural plaques (n=277); (2) healthy individuals with normal chest X-rays who were exposed to environmental asbestos (n=121); (3) healthy individuals with normal chest X-rays who were not exposed to environmental asbestos (n=118); and (4) patients with malignant pleural mesothelioma (n=24). Serum levels of carcinoembryonic antigen, cancer antigen 125, 15-3, 19-9, free T3, free T4, thyroidstimulating hormone, vitamin B12, folate, and ferritin were measured.

Results

Serum cancer antigen 125, 15-3, folic acid, vitamin B12, and ferritin levels were higher with lower free T3 levels in Group 4 than the other groups. The areas under the curve for cancer antigen 125 and 15-3 were 0.78 and 0.67, respectively in the differential diagnosis of mesothelioma from other pathologies (p<0.001 for both). Optimal limits of these biomarkers were 13.63 and 18.43 ng/mL, respectively with 83% and 75% sensitivity and 69% and 48% specificity, respectively.

Conclusion

The combination or individual use of serum cancer antigen 125, 15-3, folic acid, vitamin B12, and ferritin levels may be helpful for early diagnosis and treatment of malignant pleural mesothelioma.

Profile of anemia in acute lymphoblastic leukemia patients on maintenance therapy and the effect of micronutrient supplementation

BACKGROUND

Anemia is a common finding and important cause of morbidity in patients with acute lymphoblastic leukemia (ALL) at diagnosis or during the course of its protracted treatment. We studied profile of anemia in ALL patients on maintenance therapy and evaluated specific micronutrients as cause of this anemia.

PATIENTS AND METHODS

ALL patients who were on maintenance therapy and had grade ≥ 2 anemia were recruited for the study. Serum iron studies, folate, and vitamin B12 were done to identify micronutrient deficiency and to initiate supplementation with specific components if found to be deficient. Toxicities, improvement of anemia, micronutrient levels, and disease outcome were studied after 3 months.

RESULTS

From March 2015 to September 2016, 105 ALL patients were found to be on maintenance fulfilling the inclusion criteria. Overall, the proportion of anemia was 80%(N = 84). Majority had normocytic normochromic anemia (71%). Macrocytic anemia was seen in 18% and microcytic hypochromic in 9.5%. In patients with anemia of grade ≥ 2 (N = 84), 38 patients (45%) had biochemical deficiency of serum folate, and 7 (8%) had vitamin B12 deficiency. No biochemical evidence of iron deficiency was found. Supplementation of deficient micronutrients improved anemia: mean hemoglobin significantly increased from 8.06 ± 1.63 to 10.78 ± 1.53 (p < 0.001) at 3 months; and reduced treatment toxicities, mean number of febrile neutropenia episodes (p = 0.007), and treatment interruptions of > 2 weeks (p = 0.002) were lowered. Patients with anemia had significantly more relapses (N = 14,64%) compared to patients without anemia (N = 8,36%), (p = 0.040).

CONCLUSION

Timely identification and correction of micronutrient deficiencies causing anemia in ALL patients on maintenance can enhance treatment outcomes.

Elevated Vitamin B12 Levels and Cancer Risk in UK Primary Care: A THIN Database Cohort Study

BACKGROUND

Elevated vitamin B12 levels (B12) are associated with increased short-term cancer risk. However, the implications for early cancer detection in primary care have not been assessed.

METHODS

Individuals with plasma B12 measurements were sampled from The Health Improvement Network primary care database, UK. Persons with low B12 levels were excluded together with persons with cancer or B12 treatment before date of B12 measurement. Incident cancer was the outcome of interest and was identified through Read codes. Individuals were disaggregated according to plasma B12 levels (unit: pmol/L): 150-600 (reference range values), 601-800, 801-1,000, and >1,000.

RESULTS

Among the 757,185 persons who met the inclusion criteria, we identified 33,367 incident cancers during 2,874,059 years of follow-up. We found a higher 1-year cancer risk among the 25,783 (3.4%) persons with elevated B12 levels compared with those with normal B12 levels. After multivariable adjustment for lifestyle factors and social deprivation, persons with B12 >1,000 pmol/L had a 1-year incidence rate ratio of 4.72 (95% confidence interval: 3.99-5.58). The association showed a nonlinear dose-response pattern, and it remained robust in stratified analyses, including when reducing the risk of confounding by indication in subanalyses. The risks were particularly elevated for liver cancer, pancreas cancer, and myeloid malignancies among persons with elevated B12 levels.

CONCLUSIONS

Elevated plasma B12 levels were associated with a higher 1-year cancer risk than normal B12 levels among persons seen in UK primary care, suggesting that some cancers may affect B12 metabolism.

IMPACT

Elevated B12 may mark occult cancer.

Evaluation of Serum Trace Element and Vitamin Levels in Children With Cancer in the First 6 Months After Diagnosis

Adequate nutrient intake should be provided for the cure of children diagnosed with cancer. The aim of this study was to evaluate serum trace elements and vitamins of children with cancer at diagnosis and during treatment. Children with newly diagnosed cancer who were admitted to our center were evaluated for serum selenium, iron, ferritin, C-reactive protein, vitamin B12, folate, and 25-OH vitamin D levels at presentation, and at the third and sixth months of cancer treatment. Forty-two children (male/female: 15/27) with a median age of 8 years (range, 2 to 17) were included in the study. Mean serum B12, folate, and iron levels were within normal ranges, but selenium and 25-OH vitamin D were low at presentation and during the 6-month period. Serum ferritin levels were high in all 3 measures, but they decreased significantly at the sixth month (P=0.04). There was no relation between micronutrient deficiency and sex, or primary disease, or stage, or place of residence of the patient. In conclusion, serum trace element and vitamin deficiencies are common in children with cancer, and there is a need for further studies with larger patient series.

[What to do before a hypervitaminia B12 in the elderly]

Hypervitanimia B12 is an early marker of serious pathologies. These include solid neoplasms, malignant blood diseases and acute/chronic hepatopathies. Hypervitaminemia B12 in geriatrics is thereby an indicator in the diagnosis and prognosis of these conditions.

Elevated plasma vitamin B12 levels and cancer prognosis: A population-based cohort study

BACKGROUND

Elevated plasma vitamin B12 levels (cobalamin, Cbl) are associated with increased short-term cancer risk among patients referred for this laboratory measurement. We aimed to assess prognosis in cancer patients with elevated plasma Cbl.

METHODS

We conducted a population-based cohort study using data from Danish medical registries during 1998-2014. The study included 25,017 patients with a cancer diagnosis and Cbl levels of 200-600 pmol/L (reference/normal range), 601-800 pmol/L and >800 pmol/L measured up to one year prior to diagnosis, and a comparison cohort of 61,988 cancer patients without a plasma Cbl measurement. Patients treated with Cbl were excluded. Survival probability was assessed using Kaplan-Meier curves. Mortality risk ratios (MRR) were computed using Cox proportional hazard regression, adjusted for age, sex, calendar year, cancer stage and comorbidity, scored using the Charlson comorbidity index.

RESULTS

Survival probabilities were lower among patients with elevated Cbl levels than among patients with normal levels and among members of the comparison cohort [(1-year survival,%) Cbl: 200-600 pmol/L: 69.3%; 601-800 pmol/L: 49.6%; >800 pmol/L: 35.8%; comparison cohort: 72.6%]. Thirty-day mortality was elevated for patients with Cbl levels of 601-800 pmol/L or >800 pmol/L, compared to patients with levels of 200-600 pmol/L [(MRR (95% confidence interval): 601-800 pmol/L vs. 200-600 pmol/L: 1.9 (1.6-2.2); >800 pmol/L vs. 200-600 pmol/L: 2.7 (2.4-3.1)]. This association remained robust for 31-90-day and 91-365-day mortality, showing similar dose-response patterns.

CONCLUSION

Cancer patients with elevated Cbl levels had higher mortality than those with normal Cbl levels. These findings may have clinical significance for assessing the prognosis of cancer patients.

Plasma folate, vitamin B12, and homocysteine and cancers of the esophagus, stomach, and liver in a Chinese population

Evidence is accumulating regarding a role of micronutrients in folate metabolism in cancer risk. We investigated the associations of plasma folate, vitamin B12, and homocysteine with upper gastrointestinal (GI) cancers in a population-based case-control study in Taixing City, China. With informed consent, we recruited cases with cancers of esophagus (n = 218), stomach (n = 206), and liver (n = 204), and one common healthy control group (n = 405). A standardized epidemiologic questionnaire was used in face-to-face interviews, and blood samples were collected during interviews. We observed an inverse association between plasma folate levels and liver cancer. The adjusted odds ratio (aOR) was 0.46 [95% confidence interval (CI) = 0.24-0.88] comparing individuals in the highest quartile to those in the lowest. We found a positive association between plasma vitamin B12 levels and all three cancers. The aORs for those in the highest quartile were 2.80 (95% CI = 1.51-5.18) for esophageal cancer, 2.17 (1.21-3.89) for stomach cancer, and 9.97 (4.82-20.60) for liver cancer, comparing to those in the lowest quartile. We further observed interaction between plasma folate and vitamin B12 on these cancers. Our data indicated associations between plasma folate and vitamin B12 with upper GI cancers in Chinese population. Further research is warranted considering the debate over the necessity of food fortification.

Hypercobalaminaemia is associated with hepatic and neoplastic disease in cats: a cross sectional study

Background

When increased serum cobalamin concentrations are encountered clinically they are usually attributed to parenteral supplementation, dietary factors, or otherwise ignored. However, recently, hypercobalaminaemia has been associated with numerous diseases in humans, most notably neoplastic and hepatic disorders. The aim of this retrospective, observational, cross-sectional study was to determine the significance of increased cobalamin in cats.

Results

In total, 237 records were retrieved and 174 cats, of various ages and sexes met the inclusion criteria. A total of 42 cats had increased serum cobalamin concentration, and had not received prior supplementation. Multiple logistic regression analysis revealed that increased serum cobalamin concentration was positively related to pedigree breed (pedigree breeds more likely to have increased cobalamin concentration, odds ratio [OR] 4.24, 95% CI 1.78-10.15, P = 0.001), to having liver disease (OR 9.91, 95% CI 3.54-27.68), and to having a solid neoplasm (OR 8.54, 95% CI 1.10-66.45).

Conclusions

The results of the current study suggest that increased serum cobalamin concentrations should not be ignored in cats with no history of supplementation, and investigation for underlying hepatic or neoplastic disease is warranted.

Elevated plasma vitamin B12 levels as a marker for cancer: a population-based cohort study

BACKGROUND

A substantial proportion of patients referred for plasma vitamin B12 (cobalamin [Cbl]) measurement present with high Cbl levels, which have been reported in patients with different cancer types. However, the cancer risk among patients with newly diagnosed high Cbl levels has not been adequately examined.

METHODS

We conducted this cohort study using population-based Danish medical registries. Patients referred for Cbl measurement with levels greater than the lower reference limit (≥200 pmol/L) were identified from the population of Northern Denmark during the period of 1998 to 2009 using a database of laboratory test results covering the entire population. Data on cancer incidence (follow-up 1998-2010), Cbl treatment, and prior diagnoses were obtained from medical registries. Patients receiving Cbl treatment were excluded. Cancer risks were calculated as standardized incidence ratios (SIRs) with 95% confidence intervals (CIs), stratified by plasma Cbl levels. All statistical tests were two-sided.

RESULTS

We identified 333 667 persons without prevalent cancer and not receiving Cbl treatment. Six percent had Cbl levels greater than the upper reference limit (≥601 pmol/L). Cancer risk increased with higher Cbl levels and was highest during the first year of follow-up (Cbl 601-800 pmol/L: SIR = 3.44, 95% CI = 3.14 to 3.76; Cbl >800 pmol/L: SIR = 6.27, 95% CI = 5.70 to 6.88; both P < .001). The risks were particularly elevated for hematological and smoking- and alcohol-related cancers for persons with high Cbl levels.

CONCLUSIONS

High Cbl levels were associated with the risk of subsequently diagnosed cancer, mostly within the first year of follow-up. This may have clinical implications for the interpretation of high Cbl levels.

Three family members with elevated plasma cobalamin, transcobalamin and soluble transcobalamin receptor (sCD320)

BACKGROUND

Plasma cobalamin is requested in order to diagnose cobalamin deficiency and low levels confirm a deficient state. Here, we present three family members with unexpected high levels of cobalamin.

METHODS

We included a patient referred for cobalamin measurement due to neurological symptoms, her son and her daughter. Mother and son both suffered from myotonic dystrophy type II, while the daughter tested negative for this disease. Blood samples were analyzed for cobalamin, haptocorrin, transcobalamin, holoTC, and sCD320. We employed gel filtration and antibody precipitation for further characterization. The protein coding region of the TCN2 gene, encoding transcobalamin, was sequenced.

RESULTS

The patient, her {son} and [daughter] all had cobalamin levels above the measurement range of the routine method employed (>1476 pmol/L). Total transcobalamin and (holoTC) were 5980 (1500), {5260 (2410)} and [5630 (1340)] pmol/L, which is well above the upper reference limits of 1500 (160) pmol/L. The sCD320 concentration was also well above the upper reference limit of 97 arb.u.: 1340, {1510} and [1090] arb.u. Haptocorrin levels were within the reference range and no signs of cobalamin deficiency were found. DNA sequencing of the TCN2 gene revealed several known polymorphisms not associated with highly elevated transcobalamin levels. Upon gel filtration, sCD320 eluted as a larger molecule than previously reported. By incubation with anti-transcobalamin antibodies, we precipitated both transcobalamin and part of sCD320.

CONCLUSIONS

The high cobalamin levels were mainly explained by high levels of holoTC, possibly caused by complex formation with its soluble receptor, sCD320. The family occurrence points to a genetic explanation.

Unexpected high plasma cobalamin : proposal for a diagnostic strategy

It is well-established that more than 8% of patients examined for vitamin B12 deficiency unexpectedly have increased plasma levels of the vitamin, but so far there are no guidelines for the clinical interpretation of such findings. In this review, we summarise known associations between high plasma cobalamin and diseases. We report associations mainly with cancer, liver and kidney diseases, but also with a number of other diagnostic entities. The pathogenic background is poorly understood and is likely to be multi-factorial, involving increased concentrations of one or both of the circulating cobalamin binding proteins, transcobalamin and haptocorrin. Based on current knowledge, we suggest a strategy for the clinical interpretation of unexpected high plasma cobalamin. Since a number of the associated diseases are critical and life-threatening, the strategy promotes the concept of 'think the worst first'. It is important to realise that high cobalamin levels can be an unspecific marker for cancer. If this can be ruled out, diseases of the liver and kidney should be considered.

The pathophysiology of elevated vitamin B12 in clinical practice

Hypercobalaminemia (high serum vitamin B12 levels) is a frequent and underestimated anomaly. Clinically, it can be paradoxically accompanied by signs of deficiency, reflecting a functional deficiency linked to qualitative abnormalities, which are related to defects in tissue uptake and action of vitamin B12. The aetiological profile of high serum cobalamin predominantly encompasses severe disease entities for which early diagnosis is critical for prognosis. These entities are essentially comprised of solid neoplasms, haematological malignancies and liver and kidney diseases. This review reflects the potential importance of the vitamin B12 assay as an early diagnostic marker of these diseases. A codified approach is needed to determine the potential indications of a search for high serum cobalamin and the practical clinical strategy to adopt upon discovery of elevated cobalamin levels. While low serum cobalamin levels do not necessarily imply deficiency, an abnormally high serum cobalamin level forms a warning sign requiring exclusion of a number of serious underlying pathologies. Functional cobalamin deficiency can thus occur at any serum level.

Cobalamin related parameters and disease patterns in patients with increased serum cobalamin levels

Background

Measurement of serum cobalamin levels is routinely used to diagnose cobalamin deficiency. Surprisingly, approximately 15% of patients have high cobalamin levels and no consensus exists regarding the clinical implications.

Methods

Hospital-treated patients above 18 years of age referred for serum cobalamin measurement were included in groups of patients [percentage cobalamin supplemented] with low (<200 pmol/L, n = 200 [6%]), normal (200–600, n = 202 [6%]) high (601–1000, n = 217 [27%]) and very high (>1000, n = 199 [53%]) cobalamin levels. Total and cobalamin-saturated (holo) transcobalamin, total haptocorrin, soluble TC receptor, sCD320, and methylmalonic acid were analyzed. Data on diagnoses and medical prescriptions was obtained through medical files and the Aarhus University Prescription Database.

Results

Among patients not cobalamin supplemented median total haptocorrin and holo transcobalamin levels were markedly higher in the groups with high/very high cobalamin levels compared to groups with low/normal cobalamin levels. Median total transcobalamin and sCD320 levels were similar across the groups. A number of diagnoses were significantly associated to very high Cbl levels (odds ratio (95% confidence interval)): alcoholism (5.74 (2.76–11.96)), liver disease (8.53 (3.59–20.23)), and cancer (5.48 (2.85–10.55)). Elevated haptocorrin levels were seen in patients with alcoholism, cancer, liver-, renal-, autoimmune-, and bronchopulmonary disease. No clinical associations to sCD320 and total and holo transcobalamin levels were found.

Conclusion

In non-supplemented patients, high cobalamin levels were associated to high haptocorrin levels, and several diagnoses, including alcoholism, liver disease and cancer. Our study emphasizes that clinicians should take high serum cobalamin levels into consideration in the diagnostic process.

[Hypervitaminemia B12 (high level of cobalamin): physiopathology, role and interest in clinical practice]

Hypervitaminemia B12 or high serum level of cobalamin B12 is a frequent and clinical underestimated abnormality. Clinically, it can be sometimes paradoxically accompanied by signs of deficiency reflecting a functional deficit in relation to qualitative abnormalities related to defects in tissue uptake and action of vitamin B12. Etiological profile of hypervitaminemias B12 has mostly serious disease entities and for which early diagnosis is crucial to the plan rather than prognostic. These entities are represented mainly by solid malignancies, hematological malignancies and liver diseases. This reflects the potential significance that may have the dosage of vitamin B12 as an early marker of diagnosis of these diseases. Codified approach is needed to determine the potential indications of the search for a hypervitaminemia B12 and practice what to do to pass before the discovery of a high serum level of cobalamin.

Increased Vitamin B12 levels are associated with mortality in critically ill medical patients

BACKGROUND & AIMS

We describe an observational study in critically ill medical patients showing the association between serum Vitamin B12 levels measured on or near admission and the outcome in these patients.

METHODS

We used the database of patients admitted to the Medical Intensive Care Unit (MICU) at the Hadassah-Hebrew University Medical Center in Jerusalem, Israel, to analyze associations between patient demographics, background, diagnoses and serum Vitamin B12 levels with hospital and 90 day outcomes.

RESULTS

Higher mean Vitamin B12 levels were found in patients who did not survive their hospital stay (1719 pg/ml vs 1003 pg/ml, p < 0.01). Those who had died by 90 days after admission to the MICU also had higher Vitamin B12 levels than survivors (1593 pg/ml vs 990 pg/ml). Regression analysis showed that elevated Vitamin B12 levels were associated with increased 90 day mortality, even after controlling for other variables. Survival analysis also showed an increased mortality rate in patients with Vitamin B12 levels over 900 pg/ml (p < 0.0002).

CONCLUSIONS

Our data show that high serum Vitamin B12 levels are associated with increased mortality in critically ill medical patients. We suggest that Vitamin B12 levels should be included in the work-up of all medical intensive care patients, particularly those with a chronic health history and increased severity of illness.

[Diagnosis of vitamin B12 deficiency: a case illustrating diagnostic pitfalls]

INTRODUCTION

Vitamin B12 deficiency is a longstanding public health problem which affects more than 20% of the elderly population. Among multiple causes of vitamin B12 deficiency, Biermer's disease is currently mentioned in about 25% of the cases.

OBSERVATION

We report the case of a 71-year-old woman, taking folate substitution therapy who, over 2 years, progressively developed spinal combined sclerosis, subacute dementia and severe neuropathy leading to a bedridden state. The initial assessment revealed normocytic anemia, without vitamin B12 deficiency and without increased plasma level of biological markers. The plasma folate level was high. Vitamin B12 assay was repeated leading to the diagnosis of deficiency associated with the presence of intrinsic factor antibodies.

DISCUSSION

This observation illustrates the broad spectrum of clinical presentations of vitamin B12 deficiency. In the present case, the lack of sensitivity of biological markers delayed diagnosis and had a dramatic impact on outcome. This case highlights the importance of promoting factors such as isolated folate substitution in B12 deficient patients.