New data supporting that early diagnosis and treatment are possible and necessary in intracellular cobalamin depletion: the case of transcobalamin II deficiency

OBJECTIVES

Transcobalamin II (TC) promotes the cellular uptake of cobalamin (Cbl) through receptor-mediated endocytosis of the TC-cbl complex in peripheral tissues. TC deficiency is a rare disorder that causes intracellular Cbl depletion. It presents in early infancy with a failure to thrive, diarrhea, anemia, agammaglobulinemia, and pancytopenia. Data from five TC-deficient patients including clinical, biochemical, and molecular findings, as well as long-term outcomes, were collected.

CASE PRESENTATION

Mutation analysis revealed one unreported pathogenic variant in the TCN2 gene. One patient had exocrine pancreatic insufficiency. We conducted a retrospective analysis of C3 and C3/C2 from dried blood samples, as this is implemented for newborn screening (NBS). We detected a marked increase in the C3/C2 ratio in two samples. Treatment was based on parenteral Cbl. Three patients treated before six months of age had an initial favorable outcome, whereas the two treated later or inadequately had neurological impairment.

CONCLUSIONS

This is the first report of Argentinean patients with TC deficiency that detected a new variant in TCN2. NBS may be a tool for the early detection of TC deficiency. This data emphasizes that TC deficiency is a severe disorder that requires early detection and long-term, aggressive therapy. Accurate diagnosis is imperative, because early detection and treatment can be life-saving.

The fecal bacterial microbiota is not useful for discriminating between lymphoplasmacytic enteritis and low-grade intestinal T-cell lymphoma in cats nor for predicting therapeutic response

OBJECTIVE

To evaluate the fecal bacterial microbiota at the time of diagnosis (T0) and after 1 month of therapy (T1) in cats diagnosed with lymphoplasmacytic enteritis (LPE) or cats with low-grade intestinal T-cell lymphoma (LGITL) and to compare these findings with those of healthy cats.

ANIMALS

5 healthy cats, 13 cats with LPE, and 7 cats with LGITL were prospectively enrolled between June 2020 and June 2021.

METHODS

Fecal samples were collected at T0 and T1, and DNA was extracted for 16S ribosomal amplicon sequencing. Alpha diversity and beta diversity were computed. The taxonomic assignment was performed using sequences from the Silva v138 formatted reference database. Differential abundant taxa were selected in each taxonomic level, with the P value adjusted < .05, as the cut-off.

RESULTS

No significant differences in alpha and beta diversity were found either at T0 or T1 between healthy and diseased cats or between cats with LPE and LGITL. Beta-diversity analysis showed an increase in the Fusobacteriaceae family in cats with LGITL at T0, compared to cats with LPE. Regardless of histological diagnosis, several microbiota differences were found at T0 based on serum cobalamin levels.

CLINICAL RELEVANCE

Fecal samples were successfully used to characterize the bacteriome of the intestinal tract in cats by 16S rRNA gene sequencing. However, results highlighted that the metagenomic evaluation was not useful to discriminate between LPE and LGITL nor to predict the therapeutic response in this study population.

Hemolytic Anemia and Pancytopenia Secondary to Vitamin B12 Deficiency: Evaluation and Clinical Significance

Severe vitamin B12 deficiency presents a diagnostic challenge due to its diverse clinical manifestations, which can mimic serious hematologic disorders such as thrombotic thrombocytopenic purpura (TTP) or leukemia. The case we present here illustrates the unique characteristics of severe B12 deficiency, highlighting key differentiators from other conditions, including decreased reticulocyte counts and markedly elevated lactate dehydrogenase levels indicative of suppressed erythropoiesis. Advanced cobalamin deficiency affects all cell lines, leading to peripheral pancytopenia. Proposed mechanisms include fragile red blood cells prone to shearing, resulting in schistocyte formation, and hyperhomocysteinemia-induced oxidative stress exacerbating hemolysis. Prompt recognition and treatment with B12 replacement are critical, as illustrated by this case of hemolytic anemia and pancytopenia secondary to pernicious anemia, to prevent severe hematologic complications.

Adult Vitamin B12 Deficiency-Associated Pseudo-Thrombotic Microangiopathy: A Systematic Review of Case Reports

Cobalamin-deficient thrombotic microangiopathy or vitamin B12 deficiency presenting as pseudo-thrombotic microangiopathy is a rare disorder that can be misdiagnosed as thrombotic thrombocytopenic purpura. Patients with this condition are at risk of receiving unnecessary plasmapheresis with a potential delay in appropriate therapy with vitamin B12 supplementation. There are no established diagnostic criteria for this condition in clinical practice. We performed a systematic review of case reports published between January 2018 and January 2023 to analyze the clinical characteristics, risk factors, and patterns of laboratory markers to improve the diagnostic criteria for this condition.

Lipidomic and transcriptomic analysis of the increase in eicosapentaenoic acid under cobalamin deficiency of Schizochytrium sp

Schizochytrium sp. is a heterotrophic microorganism capable of accumulating polyunsaturated fatty acids and has achieved industrial production of docosahexaenoic acid (DHA). It also has the potential for eicosapentaenoic acid (EPA) production. In this study, it was found that the cell growth, lipid synthesis and fatty acid composition of Schizochytrium sp. were significantly affected by the level of cobalamin in the medium, especially with regard to the content of EPA in the fatty acids. The content of EPA in the fatty acids increased 17.91 times, reaching 12.00%, but cell growth and lipid synthesis were significantly inhibited under cobalamin deficiency. The response mechanism for this phenomenon was revealed through combined lipidomic and transcriptomic analysis. Although cell growth was inhibited under cobalamin deficiency, the genes encoding key enzymes in central carbon metabolism were still up-regulated to provide precursors (Acetyl-CoA) and reducing power (NADPH) for the synthesis and accumulation of fatty acids. Moreover, the main lipid subclasses observed during cobalamin deficiency were glycerolipids (including glycerophospholipids), with EPA primarily distributed in them. The genes involved in the biosynthesis of these lipid subclasses were significantly up-regulated, such as the key enzymes in the Kennedy pathway for the synthesis of triglycerides. Thus, this study provided insights into the specific response of Schizochytrium sp. to cobalamin deficiency and identified a subset of new genes that can be engineered for modification.

Vitamin B12 Deficiency Disguised As Hemolytic Anemia: A Case Presentation

This case report describes an 18-month-old male presenting with hemolytic anemia and lethargy, who was ultimately diagnosed with severe vitamin B12 deficiency. The child exhibited global developmental delays, including a lack of speech and walking skills. Initially suspected as intravascular hemolytic anemia, the normal reticulocyte count led to further investigation, which revealed low cobalamin (vitamin B12) levels. The patient received vitamin B12 injections, resulting in normalized cobalamin levels. Additional evaluations ruled out metabolic disorders and other etiologies for his anemia. Follow-up laboratory testing showed improved hemoglobin levels, and the patient was discharged with plans for close monitoring. The case emphasizes the importance of considering vitamin B12 deficiency in children, particularly those with developmental delays and anemia. Early diagnosis and treatment are crucial for preventing long-term neurological consequences associated with severe and prolonged cobalamin deficiency. Healthcare professionals should be aware of the impact of nutrient deficiencies on growth, development, and brain maturation in pediatric populations.

Kidney urinary biomarkers in patients with branched-chain amino acid and cobalamin metabolism defects

There is a clinical need for early detection of chronic kidney disease (CKD) in patients with organic acidurias. We measured kidney markers in a longitudinal study over 5 years in 40 patients with methylmalonic aciduria (Mut0 ), propionic aciduria (PA), cobalamin A (CblA), and cobalamin C (CblC) deficiencies. Neutrophil gelatinase-associated lipocalin (NGAL), calprotectin (CLP), kidney injury molecule-1 (KIM-1), dickkopf-3 (DKK-3), albumin and beta-2-microglobulin (B2MG) in urine, as well as cystatin C (CysC) in serum were quantified. In Mut0 patients, mean concentrations of B2MG, KIM-1, and DKK-3 were elevated compared with healthy controls, all markers indicative of proximal tubule damage. In PA patients, mean B2MG, albumin, and CLP were elevated, indicating signs of proximal tubule and glomerulus damage and inflammation. In CblC patients, mean B2MG, NGAL, and CLP were increased, and considered as markers for proximal and distal tubule damage and inflammation. B2MG, was elevated in all three diseases, and correlated with DKK-3 in Mut0 /CblA and with eGFR(CysC) and KIM-1 in PA patients, respectively. None of the markers were elevated in CblA patients. Significant deterioration of kidney function, as determined by steady increase in CysC concentrations was noted in seven patients within the observation period. None of the investigated biomarker profiles showed a clear increase or added value for early detection. In conclusion, we identified disease-specific biomarker profiles for inflammation, tubular, and proximal damage in the urine of Mut0 , PA, and CblC patients. Whether these biomarkers can be used for early detection of CKD requires further investigation, as significant kidney function deterioration was observed in only a few patients.

Combined Newborn Screening Allows Comprehensive Identification also of Attenuated Phenotypes for Methylmalonic Acidurias and Homocystinuria

Newborn screening (NBS) programs are effective measures of secondary prevention and have been successively extended. We aimed to evaluate NBS for methylmalonic acidurias, propionic acidemia, homocystinuria, remethylation disorders and neonatal vitamin B12 deficiency, and report on the identification of cofactor-responsive disease variants. This evaluation of the previously established combined multiple-tier NBS algorithm is part of the prospective pilot study "NGS2025" from August 2016 to September 2022. In 548,707 newborns, the combined algorithm was applied and led to positive NBS results in 458 of them. Overall, 166 newborns (prevalence 1: 3305) were confirmed (positive predictive value: 0.36); specifically, methylmalonic acidurias (N = 5), propionic acidemia (N = 4), remethylation disorders (N = 4), cystathionine beta-synthase (CBS) deficiency (N = 1) and neonatal vitamin B12 deficiency (N = 153). The majority of the identified newborns were asymptomatic at the time of the first NBS report (total: 161/166, inherited metabolic diseases: 9/14, vitamin B12 deficiency: 153/153). Three individuals were cofactor-responsive (methylmalonic acidurias: 2, CBS deficiency: 1), and could be treated by vitamin B12, vitamin B6 respectively, only. In conclusion, the combined NBS algorithm is technically feasible, allows the identification of attenuated and severe disease courses and can be considered to be evaluated for inclusion in national NBS panels.

Serum cobalamin and methylmalonic acid concentrations in juvenile dogs with parvoviral enteritis or other acute enteropathies

BACKGROUND

Low serum cobalamin concentrations have been associated with ileal malabsorption in dogs with chronic enteropathy. Increased serum methylmalonic acid (MMA) concentrations indicate cobalamin deficiency on a cellular level. Few studies have evaluated serum cobalamin concentrations or methylmalonic acid concentrations in juvenile dogs with parvoviral enteritis or nonparvoviral acute enteropathies.

OBJECTIVES

Evaluate serum cobalamin and methylmalonic acid concentrations in juvenile dogs (6 weeks to 10 months old) with parvoviral enteritis or nonparvoviral acute enteropathy.

ANIMALS

Thirty-one juvenile dogs with parvoviral enteritis, 29 dogs with nonparvoviral acute diarrhea (NPVAD), and 40 healthy juvenile control dogs.

METHODS

Single-center, prospective, observational, cross-sectional study. Serum cobalamin and, when sufficient serum was available, MMA concentrations were measured.

RESULTS

Most serum cobalamin concentrations were within the adult reference interval. Serum cobalamin concentrations in healthy dogs (median, 848 ng/L; range, 293-1912 ng/L) were significantly higher than in dogs with parvoviral enteritis (P = .0002; median, 463 ng/L; range, <150-10 000 ng/L) or dogs with NPVAD (P = .02; median, 528 ng/L; range, 160-8998 ng/L). Serum MMA concentrations were not significantly different between groups (healthy dogs: median, 796 nmol/L; range, 427-1933 nmol/L; parvoviral enteritis: median, 858 nmol/L; range, 554-3424 nmol/L; NPVAD: median, 764 nmol/L; range, 392-1222 nmol/L; P = .1).

CONCLUSIONS AND CLINICAL IMPORTANCE

Juvenile dogs with parvoviral enteritis or NPVAD had lower serum cobalamin concentrations than healthy juvenile dogs. However, based on serum MMA concentrations cellular cobalamin deficiency was not apparent.

Autoimmune Polyglandular Syndrome with Refractory Gait Disturbance

Autoimmune polyglandular syndrome (APS) causes autoimmune diseases of multiple organs and can also present with neurological symptoms. We here report a 58-year-old man who presented with progressive gait disturbance that had started 7 years ago. He had spasticity, reduced deep sensations, and truncal cerebellar ataxia. Laboratory examinations revealed autoantibody-related cobalamin deficiency and the presence of anti-thyroid antibodies and anti-glutamic acid decarboxylase antibodies. His gait worsened after cobalamin replenishment, but additional steroid therapy was effective. APS can cause refractory gait disturbance that requires not only cobalamin replenishment but also immunotherapy.

Effect of oral or injectable supplementation with cobalamin in dogs with hypocobalaminemia caused by chronic enteropathy or exocrine pancreatic insufficiency

Background

Recent studies have shown similar efficacy of oral supplementation of cobalamin compared to injectable supplementation in dogs, but few prospective, randomized studies have been published.

Objectives

To evaluate efficacy of oral or injectable supplementation with cobalamin in normalizing serum cobalamin and methylmalonic acid (MMA) concentrations in dogs with hypocobalaminemia caused by either chronic enteropathy (CE) or exocrine pancreatic insufficiency (EPI).

Animals

Forty‐six client owned dogs with hypocobalaminemia.

Methods

Prospective randomized clinical trial. Dogs were divided into 2 groups (CE or EPI), and randomized to receive oral or injectable supplementation of cobalamin. Each dog had 3 visits and serum cobalamin and MMA concentrations were measured at each visit.

Results

In dogs with CE, serum cobalamin concentrations increased with oral (P = .02; median 149 [range 149‐231] to 733 [166‐1467] ng/L, median difference 552 [95% CI: 181‐899] ng/L) or injectable (P < .01; 168 [149‐233] to 563 [234‐965] ng/L, 367 [187‐623] ng/L) supplementation. In dogs with EPI, serum cobalamin concentrations increased with oral (P = .01; 162 [149‐214] to 919 [643‐3863] ng/L, 705 [503‐3356] ng/L) or injectable (P = .01; 177 [149‐217] to 390 [243‐907] ng/L, 192 [89‐361] ng/L) supplementation. Serum MMA concentrations decreased with oral or injectable supplementation in dogs with CE, but only with oral supplementation in dogs with EPI.

Conclusions and Clinical Importance

Oral supplementation is an alternative for cobalamin supplementation in dogs with hypocobalaminemia caused by CE or EPI.

Masked arterial hypertension in a 64-year-old man with primary aldosteronism

PURPOSE

Primary aldosteronism is one of the most frequent causes of secondary arterial hypertension, and whether primary aldosteronism is associated with masked hypertension is unknown.

MATERIALS AND METHODS

We describe a 64-year-old man with a history of hypothyroidism, recurring hypokalaemia, and normal home and office blood pressure values. Ambulatory blood pressure monitoring revealed masked hypertension with strikingly high systolic blood pressure variability and typical hypertension-mediated organ damage.

RESULTS

The patient required gradual escalation of antihypertensive medication to four drugs. During the diagnostic process we identified primary aldosteronism, cobalamin deficiency, severe obstructive sleep apnoea, and low baroreflex sensitivity (1.63 ms/mmHg). Following unilateral adrenalectomy, cobalamin supplementation and continuous positive airway pressure, we observed a spectacular improvement in the patient's blood pressure control, baroreflex sensitivity (4.82 ms/mmHg) and quality of life.

CONCLUSIONS

We report an unusual case of both masked arterial hypertension and primary aldosteronism. Elevated blood pressure values were masked in home and office measurements by coexisting hypotension which resulted most probably from deteriorated baroreflex sensitivity. Baroreflex sensitivity increased following treatment, including unilateral adrenalectomy. Hypertension can be masked by coexisting baroreceptor dysfunction which may derive from structural but also functional reversible changes.

Pseudothrombotic Microangiopathy as a Rare Presentation of Cobalamin Deficiency

The hematological manifestations of cobalamin (vitamin B12) deficiency may range from asymptomatic to life-threatening forms. Pseudothrombotic microangiopathy is a rare but severe presentation, characterized by the presence of hemolysis and schistocytosis, that is completely reversible after vitamin supplementation.

We present a challenging diagnostic approach of a 55-year-old man who presented with high hemolytic markers, pancytopenia, and schistocytes on the peripheral smear due to acquired cobalamin deficiency. Subsequent testing revealed positive anti-intrinsic factor and anti-parietal cell antibodies consistent with pernicious anemia. Cobalamin replacement led to the resolution of microangiopathic hemolysis and clinical improvement, thereby confirming the diagnosis.

This case highlights the importance of early recognition of this syndrome, which is often misdiagnosed as true microangiopathic hemolytic anemia, confounding appropriate management.

Health Outcomes of Infants with Vitamin B12 Deficiency Identified by Newborn Screening and Early Treated

OBJECTIVE

To evaluate the clinical outcomes at age 1.5 ± 0.5 years of infants with vitamin B₁₂ deficiency identified by newborn screening (NBS).

STUDY DESIGN

Prospective multicenter observational study on health outcomes of 31 infants with vitamin B₁₂ deficiency identified by NBS. Neurodevelopment was assessed by the Denver Developmental Screening Test.

RESULTS

In 285 862 newborns screened between 2016 and 2019, the estimated birth prevalence of vitamin B₁₂ deficiency was 26 in 100 000 newborns, with high seasonal variations (lowest in summer: 8 in 100 000). Infants participating in the outcome study (N = 31) were supplemented with vitamin B₁₂ for a median (range) of 5.9 (1.1-16.2) months. All achieved age-appropriate test results in Denver Developmental Screening Test at age 15 (11-23) months and did not present with symptoms characteristic for vitamin B₁₂ deficiency. Most (81%, n = 25) mothers of affected newborns had a hitherto undiagnosed (functional) vitamin B₁₂ deficiency, and, subsequently, received specific therapy.

CONCLUSIONS

Neonatal vitamin B₁₂ deficiency can be screened by NBS, preventing the manifestation of irreversible neurologic symptoms and the recurrence of vitamin B₁₂ deficiency in future pregnancies through adequate treatment of affected newborns and their mothers. The high frequency of mothers with migrant background having a newborn with vitamin B₁₂ deficiency highlights the need for improved prenatal care.

Recognizing Subacute Combined Degeneration in Patients With Normal Vitamin B12 Levels

Vitamin B12 deficiency is commonly associated with dementia in patients over the age of 65 years; however, it can affect people of all ages. Recognizing the clinical sequelae of subacute combined degeneration is essential for the timely diagnosis and treatment of vitamin B12 deficiency. In this report, we describe a case of a young man presenting with several months of neuropathy, depression, and abdominal symptoms. His initial vitamin B12 levels were within normal limits, but an elevated methylmalonic acid level and subacute combined degeneration of his spine on MRI confirmed the diagnosis of vitamin B12 deficiency. The patient later tested positive for autoantibodies associated with pernicious anemia. His symptoms improved with intramuscular injections of cyanocobalamin. This case highlights the importance of recognizing vitamin B12 deficiency in patients of all age groups even in the setting of apparently "normal" B12 levels.

Pernicious anemia: Pathophysiology and diagnostic difficulties

Pernicious anemia (PA) is the most common cause of vitamin B12 (cobalamin) deficiency anemia in the world. It is an autoimmune disease, comprising of salient features of autoimmune chronic atrophic gastritis (CAG) and cobalamin deficiency (CD). Although the anemia was first described as pernicious, it may well be controlled with vitamin B12 replacement. The onset and progression of PA is often insidious. Alternatively, patients may have no anemic symptoms since they become acclimatized to the subtle nature of the disease. Oftentimes, there is a possibility that the underlying disease may be missed unless a full blood count (FBC) is investigated, leading to hindrance in the treatment journey. Diagnostic challenges remain tangible for many practicing clinicians, since there is lack of reliable cobalamin assays to diagnose CD as well as clinical mimics, which simulate many other hematological conditions, such as myelodysplastic syndrome, acute leukemia, sideroblastic anemias, bone marrow failure states, thrombotic microangiopathy, and thromboembolism. Moreover, prompt recognition of the symptoms of CD is also vital, because some neurologic sequalae may become irreversible despite replenishing cobalamin. Herein, we discuss a literature review on the pathophysiology, challenging clinical presentations and diagnostic difficulties of PA. Since the cobalamin replacement therapy for PA is straightforward, it will not be discussed in this review.

[Cobalamin in the complex treatment and prevention of cognitive impairment]

Cognitive impairment (CI) develops not only in structural damage to the central nervous system, but also in encephalopathies of dysmetabolic and deficiency etiology. Recently, special attention is focused on the appearance of CI due to the deficiency of cobalamin (vitamin B₁₂) and folic acid (FA), the change in the level of homocysteine (HC). To detect vitamin B₁₂ deficiency is possible by examining key biomarkers in serum based on a decrease in the levels of vitamin B₁₂ and holotranscobalamin, and levels of methylmalonic acid (MMA) and HC. The article presents an analysis of studies conducted in Norway, Korea, India, and other countries to assess the risks of CI in the presence of reduced levels of vitamin B₁₂ in the elderly, which demonstrated a decrease in brain volume in the elderly (according to MRI data) in combination with altered test parameters that assess cognitive functions. In many studies, female patients with reduced levels of vitamin B₁₂ predominated among the studied patients. Also, some studies have demonstrated the effectiveness of complex CI therapy with the inclusion of vitamin B₁₂ (both for oral and intravenous administration). Oral vitamin B₁₂ therapy at a dose of 1000 μg has been shown to be adequate for the treatment of vitamin B₁₂ deficiency. Also, the administration of vitamin B₁₂ for prophylactic purposes is recommended for patients with subnormal or borderline concentrations of vitamin B₁₂ in the blood serum.

Common Pitfalls in the Management of Patients with Micronutrient Deficiency: Keep in Mind the Stomach

Micronutrient deficiencies are relatively common, in particular iron and cobalamin deficiency, and may potentially lead to life-threatening clinical consequences when not promptly recognized and treated, especially in elderly patients. The stomach plays an important role in the homeostasis of some important hematopoietic micronutrients like iron and cobalamin, and probably in others equally important such as ascorbic acid, calcium, and magnesium. A key role is played by the corpus oxyntic mucosa composed of parietal cells whose main function is gastric acid secretion and intrinsic factor production. Gastric acid secretion is necessary for the digestion and absorption of cobalamin and the absorption of iron, calcium, and probably magnesium, and is also essential for the absorption, secretion, and activation of ascorbic acid. Several pathological conditions such as Helicobacter pylori-related gastritis, corpus atrophic gastritis, as well as antisecretory drugs, and gastric surgery may interfere with the normal functioning of gastric oxyntic mucosa and micronutrients homeostasis. Investigation of the stomach by gastroscopy plus biopsies should always be considered in the management of patients with micronutrient deficiencies. The current review focuses on the physiological and pathophysiological aspects of gastric acid secretion and the role of the stomach in iron, cobalamin, calcium, and magnesium deficiency and ascorbate homeostasis.

Vitamine B12 deficiency in children: a diagnostic challenge

Cobalamin or vitamin B12 (vitB12) is involved in DNA synthesis, haematopoiesis and myelinisation. Consequently, vitB12 deficiency causes various symptoms, such as megaloblastic anaemia, neurologic signs or pancytopenia. Despite possible severe symptoms, vitB12 deficiency can present asymptomatically. We report six paediatric patients with different aetiologies of vitB12 deficiency ranging from a subtle to a more overt presentation. VitB12 deficiency is a diagnostic challenge due to the lack of consensus on normal values of vitB12 and its co-markers (folate, holotranscobalamin, methylmalonic acid, homocysteine) and the lack in specificity and sensitivity of the serum vitB12 analysis. All cases were treated with parenteral vitB12. Last decades, evidence supporting high dose oral treatment being as effective as the intramuscular (IM) therapy, also in children, is growing.

Suspected Metformin-induced Cobalamin Deficiency Mimicking Thrombotic Thrombocytopenic Purpura

Thrombotic thrombocytopenic purpura (TTP) can often be life threatening and requires timely diagnosis and prompt initiation of plasmapharesis. Cobalamin deficiency can closely mimic TTP and distinguishing between the two diseases can prove to be a diagnostic challenge. Previously, cobalamin-related pseudo-TTP has been associated with pernicious anemia, dietary insufficiency and hereditary disorders of cobalamin activation. Here in, we discuss the first case of suspected metformin-induced cobalamin deficiency causing pseudo-TTP. Our patient was a 36-year-old female with type 2 diabetes mellitus on metformin for eight years who presented with hemolytic anemia, thrombocytopenia, schistocytes and mild acute renal failure. The initial impression was TTP; however, further workup revealed very low serum cobalamin levels and elevated methylmalonic acid levels. Apart from metformin use, no other cause of cobalamin deficiency was identified. We recommended upper gastrointestinal endoscopy to definitively rule out pernicious anemia. 

Vitamin B12 Deficiency Is Prevalent Among Czech Vegans Who Do Not Use Vitamin B12 Supplements

As not much is known about the prevalence and predictors of nutritional deficiencies among vegans in the Czech Republic, we evaluated whether supplement use and duration of adherence to the vegan diet are associated with the risk of cobalamin and iron deficiencies. Associations between self-reported supplementation and duration of vegan diet with biomarkers of cobalamin (serum cobalamin, holotranscobalamin, homocysteine, folate) and iron status (serum ferritin, iron binding capacity, transferrin and saturation of transferrin) were assessed by cross-sectional analyses of medical data from a clinical nutrition center. Data from 151 (72 females) adult vegans (age 18–67 years), who were free of major chronic diseases and 85 (40 females) healthy non-vegans (age 21–47 years) were analyzed. Overall, vegans had significantly lower cobalamin, hemoglobin and ferritin levels, but higher folate and MCV values compared to non-vegans. Vegans not using cobalamin supplements were at higher risk of low plasma cobalamin than regularly supplementing vegans (OR: 4.41, 95% CI 1.2–16.16 for cobalamin, OR: 19.18, 95% CI 1.02–359.42 for holotranscobalamin), whereas no significant differences in cobalamin status related to duration of the vegan diet were observed. Regularly supplementing vegans had similar levels of cobalamin/holotranscobalamin as non-vegans. Despite lower ferritin and hemoglobin levels, there was no indication of a higher risk of iron-deficiency among vegans. To conclude cobalamin deficiency risk depends on supplementation status and not on the duration of an exclusive vegan diet, which underlines the need to integrate cobalamin status monitoring and counselling on supplement use in routine clinical care in the Czech Republic.

Review of cobalamin status and disorders of cobalamin metabolism in dogs

Disorders of cobalamin (vitamin B₁₂) metabolism are increasingly recognized in small animal medicine and have a variety of causes ranging from chronic gastrointestinal disease to hereditary defects in cobalamin metabolism. Measurement of serum cobalamin concentration, often in combination with serum folate concentration, is routinely performed as a diagnostic test in clinical practice. While the detection of hypocobalaminemia has therapeutic implications, interpretation of cobalamin status in dogs can be challenging. The aim of this review is to define hypocobalaminemia and cobalamin deficiency, normocobalaminemia, and hypercobalaminemia in dogs, describe known cobalamin deficiency states, breed predispositions in dogs, discuss the different biomarkers of importance for evaluating cobalamin status in dogs, and discuss the management of dogs with hypocobalaminemia.

Subcortical lesions due to cobalamin deficiency: an unusual MRI lesion pattern

We present a 44-year-old male patient with new onset of right focal epilepsy and bilateral hand hypesthesia. Cerebral MRI showed bilateral T2w/DWI hyperintense subcortical lesions in the cingulate gyrus, insula, and amygdala, whereas spinal MRI revealed a cervical posterior column lesion, corresponding to subacute combined degeneration. Laboratory workup revealed a cobalamin deficiency due to type A gastritis, and no evidence of antibodies associated with limbic encephalitis. After sufficient cobalamin substitution, the cerebral and spinal lesions gradually regressed. Our case represents a unique cerebral subcortical MRI lesion pattern in a patient with epilepsy and cobalamin deficiency. Thus, the latter represents an important differential diagnosis for autoimmune encephalitis.

Imerslund-Gräsbeck Syndrome in an Infant with a Novel Intronic Variant in the AMN Gene: A Case Report

Imerslund-Gräsbeck syndrome (IGS) is a rare autosomal recessive disorder clinically characterized by megaloblastic anemia, benign mild proteinuria, and other nonspecific symptoms. Several pathogenetic variants in the amnionless (AMN) or cubilin (CUBN) genes have been described in IGS. We describe a case of IGS with urinary tract infection and mild but persistent proteinuria at onset in an 11-month-old female child. With the appearance of macrocytic anemia, aphthous stomatitis, and neurological signs, IGS was clinically suspected, and vitamin B12 parenteral therapy was started. Sequence analysis showed the presence of a novel intronic variant c.513+5G>A of AMN, never before described in the literature, that was in compound heterozygosity with the known pathogenetic variant c.1006+34_1007-31del. Analysis extension to the parents revealed the presence of variant c.1006+34_1007-31 in the father and c.513+5G>A in the mother. In the present case with IGS, the novel intronic variant of AMN was identified in “trans” with a known pathogenic variant (c.1006-31 del) and the new variant was interpreted to be pathogenetic since it was not found in the public database of polymorphisms and because it was predicted to alter a donor splicing site. Our case underlines the relevance in detecting certain subtle symptoms, such as mild but persistent proteinuria associated with megaloblastic anemia, to reach a correct diagnosis of a rare but treatable disorder.

Vitamin B12 Deficiency Induces Imbalance in Melanocytes Homeostasis-A Cellular Basis of Hypocobalaminemia Pigmentary Manifestations

Vitamin B₁₂ deficiency causes significant changes in cellular metabolism leading to various clinical symptoms, such as hematological, psychiatric, and neurological disorders. We hypothesize that skin pigmentation disorders may be a diagnostically important manifestation of vitamin B₁₂ deficiency, however the cellular and molecular mechanisms underlying these effects remain unknown. The aim of this study was to examine the effect of vitamin B₁₂ deficiency on melanocytes homeostasis. Hypocobalaminemia in vitro model was developed by treating epidermal melanocytes with synthesized vitamin B₁₂ antagonist—hydroxycobalamin(c-lactam). The cells were examined using immunoenzymatic, spectrophotometric, and fluorimetric assays as well as image cytometry. Significant melanogenesis stimulation—the increase of relative melanin content and tyrosinase activity up to 131% and 135%, respectively—has been indicated. Cobalamin-deficient cells displayed the elevation (by 120%) in reactive oxygen species level. Moreover, the redox status imbalance was stated. The study provided a scientific evidence for melanocytes homeostasis disturbance under hypocobalaminemia, thus indicating a significant element of the hyperpigmentation mechanism due to vitamin B₁₂ deficiency. Furthermore, the implication between pigmentary and hematological and/or neuropsychiatric symptoms in cobalamin-deficient patients may be an important issue.

THE RISK OF COBALAMIN DEFICIENCY SYMPTOMS RELATED TO LONG-TERM METFORMIN USE IN T2DM PATIENTS

Background

Metformin is the first-line oral antidiabetic agent used in the treatment of diabetes mellitus. One of the adverse reactions of the long term use of metformin is cobalamin malabsorption. Clinical and laboratory findings are important in the diagnosis of cobalamin deficiency.

Objective

This study aimed to evaluate the risk of cobalamin deficiency symptoms related to long-term use of metformin in type 2 diabetes mellitus patients at Pasar Rebo General Hospital in Jakarta.

Setting

This quantitative, observational study with retrospective cohort design was conducted in outpatient department Pasar Rebo General Hospital November 2015 until January 2016.

Methods

200 subjects were recruited and divided into two groups, patients who had been taking metformin for 1-3 years and patients who had been taking metformin for more than 3 years. Each patient was assessed for the presence of cobalamin deficiency symptoms.

Main outcome measure

Cobalamin deficiency symptoms evaluated were symptoms of neuropathy (measured by DN4 questionnaire) and hematologic abnormalities associated to cobalamin deficiency, i.e. macrocytic erythrocyte, hypersegmented neutrophils, and giant bands.

Results

There are significant differences in the proportions of neuropathy symptoms (RR 2.36, 95%, p=0.000) and hematologic abnormalities (RR 1.5, 95%, p=0.007) between the two groups.

Conclusions

Long-term use of metformin (≥3 years) may increase the risk of cobalamin deficiency symptoms in type 2 diabetes mellitus patients.

Exploring Vitamin B12 Deficiency in Sleeve Gastrectomy from a Histological Study of a Cadaveric Stomach and Ileum

INTRODUCTION

Vitamin B12 deficiency is more commonly found among patients who have undergone Roux-en-Y gastric bypass (RYGB) as compared to those with post-sleeve gastrectomies (SG). The major difference between SG and RYGB is that the latter greatly bypasses the stomach whereas the former simply reduces the gastric volume.

PURPOSE

The aim of this article was to study the stomach and the distal ileum histologically in a cadaver with SG to explain the higher rate of incidences of vitamin B12 deficiency seen in patients post-RYGB relative to patients post-SG. Since the stomach is the major variable in these two procedures, we hypothesize that it has the ability to regenerate and increase its surface area to compensate for the loss of its volume in SG patients.

MATERIAL AND METHODS

Tissue biopsies and hematoxylin and eosin stains were performed from various anatomical locations of the GI tract, specifically the gastric fundus, body, and antrum, and from the distal ileum of the small intestine of a cadaver with SG and another without SG (control).

RESULTS

Compared with the control, the SG cadaver's gastric tissue biopsies were significant for chronic gastritis and hypertrophy of the muscularis externa layer. More importantly, parietal cell hyperplasia and deeper mucosal glands were also noted in the SG cadaver supporting the hypothesis.

CONCLUSIONS

The compensatory role of an intact stomach, given its ability to regenerate parietal cells and increase its numbers in the gastric fundus and body, can be better appreciated in a gastric-sparing procedure such as SG versus RYGB in terms of limiting vitamin B12 deficiencies.

Oral Cyanocobalamin is Effective in the Treatment of Vitamin B12 Deficiency in Crohn's Disease

Cobalamin deficiency is common in patients with Crohn’s disease (CD). Intramuscular cobalamin continues to be the standard therapy for the deficiency and maintenance treatment in these patients, although oral route has been demonstrated to be effective in other pathologies with impaired absorption. Our aims were to evaluate the efficacy of oral therapy in the treatment of cobalamin deficiency and in long-term maintenance in patients with Crohn’s disease. We performed a multicenter retrospective cohort study that included 94 patients with Crohn’s disease and cobalamin deficiency. Seventy-six patients had B12 deficiency and 94.7% of them normalized their cobalamin levels with oral treatment. The most used dose was 1 mg/day, but there were no significant differences in treatment effectiveness depending on the dose used (≥1 mg/24 h vs. <1 mg/24 h). Eighty-two patients had previous documented B12 deficiency and were treated with oral B12 to maintain their correct cobalamin levels. After a mean follow-up of 3 years, the oral route was effective as maintenance treatment in 81.7% of patients. A lack of treatment adherence was admitted by 46.6% of patients in who the oral route failed. In conclusion, our study shows that oral cyanocobalamin provides effective acute and maintenance treatment for vitamin B12 deficiency caused by CD with or without ileum resection.

Sensory Neuronopathy Revealing Severe Vitamin B12 Deficiency in a Patient with Anorexia Nervosa: An Often-Forgotten Reversible Cause

Vitamin B12 (B12) deficiency is known to be associated with various neurological manifestations. Although central manifestations such as dementia or subacute combined degeneration are the most classic, neurological manifestations also include sensory neuropathies. However, B12 deficiency is still rarely integrated as a potential cause of sensory neuronopathy. Moreover, as many medical conditions can falsely normalize serum B12 levels even in the context of a real B12 deficiency, some cases may easily remain underdiagnosed. We report the illustrating case of an anorexic patient with sensory neuronopathy and consistently normal serum B12 levels. After all classical causes of sensory neuronopathy were ruled out, her clinical and electrophysiological conditions first worsened after folate administration, but finally improved dramatically after B12 administration. B12 deficiency should be systematically part of the etiologic workup of sensory neuronopathy, especially in a high risk context such as anorexia nervosa.

Relationship between cobalamin deficiency and delirium in elderly patients undergoing cardiac surgery

BACKGROUND

Delirium is common after cardiac surgery and is independently associated with increased morbidity, mortality, prolonged hospital stays, and higher costs. Cobalamin (vitamin B12) deficiency is a common cause of neuropsychiatric symptoms and affects up to 40% of elderly people. The relationship between cobalamin deficiency and the occurrence of delirium after cardiac surgery has not been examined in previous studies. We examined the relationship between cobalamin deficiency and delirium in elderly patients undergoing coronary artery bypass grafting (CABG) surgery.

MATERIAL AND METHODS

A total of 100 patients with cobalamin deficiency undergoing CABG were enrolled in this retrospective study. Control group comprised 100 patients without cobalamin deficiency undergoing CABG. Patients aged 65 years or over were included. Diagnosis of delirium was made using Intensive Care Delirium Screening Checklist. Delirium severity was measured using the Delirium Rating Scale-revised-98.

RESULTS

Patients with cobalamin deficiency had a significantly higher incidence of delirium (42% vs 26%; P=0.017) and higher delirium severity scores (16.5±2.9 vs 15.03±2.48; P=0.034) than patients without cobalamin deficiency. Cobalamin levels were significantly lower in patients with delirium than patients without delirium (P=0.004). Delirium severity score showed a moderate correlation with cobalamin levels (ρ=-0.27; P=0.024). Logistic regression analysis demonstrated that cobalamin deficiency was independently associated with postoperative delirium (OR 1.93, 95% CI 1.03-3.6, P=0.038).

CONCLUSION

The results of our study suggest that cobalamin deficiency may be associated with increased risk of delirium in patients undergoing CABG. In addition, we found that preoperative cobalamin levels were associated with the severity of delirium. This report highlights the importance of investigation for cobalamin deficiency in patients undergoing cardiac surgery, especially in the elderly.

Effects of oral crystalline cyanocobalamin 1000 μg/d in the treatment of pernicious anemia: An open-label, prospective study in Ten Patients

BACKGROUND

Standard treatment of cobalamin (vitamin B12) deficiency involvesregular (1000 μg/mo) IM cyanocobalamin administration. It has been suggested that high-dose (>2000 μg/d) oral cyanocobalamin may be effective in patients with pernicious anemia.

OBJECTIVE

The aim of this study was to assess the efficacy and tolerability of oral crystalline cyanocobalamin 1000 μg/d in patients with cobalamin deficiency related to established pernicious anemia.

METHODS

This open-label, prospective study was conducted at StrasbourgUniversity Hospital, Strasbourg, France. Patients aged ≥18 years with well-documented cobalamin deficiency related to pernicious anemia were enrolled. Patients received crystalline cyanocobalamin 1000 μg QD PO (capsule) for at least 3 months. Serum cobalamin, folate, iron, and homocysteine concentrations were measured, and a complete blood count was obtained, before (month 0; baseline) and after treatment.

RESULTS

Ten patients (7 women, 3 men; mean [SD] age, 72.1 [15.5] years) entered the study. After 3 months of treatment, serum cobalamin concentration increased in all 9 patients in whom it was measured (mean [SD] increase, 117.4 [30.8] pg/mL; P < 0.001 vs baseline). Serum cobalamin concentrations were normalized (>200 pg/mL) in 6 patients. The serum cobalamin concentration was unavailable in 1 patient because of technical problems. Eight patients had increased hemoglobin concentrations (mean [SD] increase, 2.5 [2.4] g/dL; P < 0.01 vs baseline). All 10 patients had decreased mean erythrocyte corpuscular volumes (mean [SD] decrease, 10.4 [6.2] fL; P < 0.003 vs baseline). Four patients received concomitant blood transfusions or folate and iron supplementation. Three patients experienced clinical improvement in paresthesia, reflex abolition, or combined medullary sclerosis (each, 1 patient).

CONCLUSION

The results of this small study in patients with cobalamin deficiencyrelated to pernicious anemia suggest that oral crystalline cyanocobalamin 1000 μg/d may be an effective treatment.

Neurologic aspects of cobalamin (B12) deficiency

Optimal functioning of the central and peripheral nervous system is dependent on a constant supply of appropriate nutrients. Particularly important for optimal functioning of the nervous system is cobalamin (vitamin B12). Cobalamin deficiency is particularly common in the elderly and after gastric surgery. Many patients with clinically expressed cobalamin deficiency have intrinsic factor-related malabsorption such as that seen in pernicious anemia. The commonly recognized neurological manifestations of cobalamin deficiency include a myelopathy with or without an associated neuropathy. This review deals with neurological aspects of vitamin B12 deficiency and attempts to highlight recent developments.

Older adult psychiatric inpatients with non-cognitive disorders should be screened for vitamin B12 deficiency

OBJECTIVE

Vitamin B12 (B12) deficiency is most prevalent among older adults. Practice guidelines recommend screening older adults with symptoms of cognitive disorder for B12 deficiency. However, guidelines for non-cognitive psychiatric disorders typically do not mention screening older adults for B12 deficiency. The purpose of this study was to determine whether routine screening of older adult psychiatric inpatients for B12 deficiency, regardless of cognitive symptoms, is clinically justified.

DESIGN

We conducted a retrospective chart-review study of consecutive inpatient admissions.

SETTING

Older Adult Acute Psychiatric Inpatient Unit at the University of Maryland Medical Center from 10/2007-4/2010.

PARTICIPANTS

Acute psychiatric inpatients aged ≥50 years who met inclusion criteria (N=374).

MEASUREMENTS

Mean (SD) B12 levels and percentages of probable (<180pg/mL) and possible (180-350pg/mL) B12 deficiency as well as characteristics of patients with probable and possible B12 deficiency compared to patients with optimal B12 levels.

RESULTS

Mean (SD) B12 levels and percentages of probable and possible B12 deficiency, respectively, for cognitive disorder patients [468 (284) pg/mL, 7.8 % (n=5) and 29.7% (n=19)] and for non-cognitive disorder patients [481(268) pg/mL, 4.8 %(n=15) and 33.2%( n=103)] were not significantly different (t=0.339, df=372, P=0.735; χ2=1.084, df=2, P=0.582, respectively).

CONCLUSION

Considering the potential benefits and low costs of screening and treatment, we conclude that it is justified to routinely screen older adult psychiatric inpatients for B12 deficiency whether or not cognitive disorder symptoms are present.

Genetic and genomic systems to study methylmalonic acidemia

Methylmalonic acidemia (MMAemia) is the biochemical hallmark of a group of genetic metabolic disorders that share a common defect in the ability to convert methylmalonyl-CoA into succinyl-CoA. This disorder is due to either a mutant methylmalonyl-CoA mutase apoenzyme or impaired synthesis of adenosylcobalamin, the cofactor for this enzyme. In this article, we will provide an overview of the pathways disrupted in these disorders, discuss the known metabolic blocks with a particular focus on molecular genetics, and review the use of selected model organisms to study features of methylmalonic acidemia.