Serum Cobalamin Research Articles

Impact of Serum Folate and Vitamin B12 on Mental Health in Patient Admitted at Razi Psychiatric Hospital

Vitamin B12 (cobalamin) is one of the essential vitamins that affect various systems in the body, including the central nervous system and plays an important role in the metabolism of the nervous system, although its exact role under pathological conditions is not fully understood. The present study aimed to assessing vitamin B12 & serum folate in patient admitted at Razi psychiatric hospital. A cross section study subjects were inpatients with psychiatric disorder, patients from 21 to 60 years old. In this group of 40 psychiatric patients, there is no evidence of clinically relevant changes in serum vitamin B12 and folate level. Vitamin B12 deficiency can occur despite “normal” serum cobalamin levels; therefore, measuring homocysteine and methyl malonic acid can decrease false-negative findings.

Comparing Holotranscobalamin and Total Vitamin B12 in Diagnosing Vitamin B12 Deficiency in Megaloblastic Anemia Patients.

Background Megaloblastic anemia is characterized by abnormally large red blood cells caused by a deficiency in either vitamin B12 or folic acid, both of which are essential for DNA synthesis. Vitamin B12 insufficiency can lead to severe neurological damage, making early identification of vitamin B12 deficiency crucial to prevent irreversible harm. Vitamin B12 deficiency results in decreased levels of holotranscobalamin (Holo-TC) and increased levels of methylmalonic acid (MMA). Methylmalonic acid is considered the gold standard for diagnosing B12 deficiency because it is a specific marker that rises when B12 is insufficient, even when serum B12 levels appear normal. Elevated MMA levels reflect impaired B12 metabolism, making it a critical tool for early detection and intervention. Previous research indicates that Holo-TC, the active form of vitamin B12 available to cells, is a more specific diagnostic tool for early vitamin B12 deficiency than total B12. This study aims to determine the diagnostic validity of total vitamin B12 and Holo-TC using MMA as the gold standard in patients with megaloblastic anemia. Methods A total of 95 megaloblastic anemia patients were selected from Jinnah Hospital and Lahore General Hospital, Lahore, Pakistan, after receiving approval from the ethical review committees. This was a cross-sectional study. Whole blood, serum, and urine samples were collected in ethylenediamine tetraacetic acid (EDTA) vials, gel vials, and urine containers, respectively. The EDTA samples were used for complete blood count measurements using a hematology analyzer (Sysmex-XT 1800i, Sysmex America, Inc., Mundelein, IL), while serum and urine samples were employed for the detection of serum folic acid, cobalamin, Holo-TC, and MMA levels through manual enzyme-linked immunosorbent assay (ELISA) techniques. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of Holo-TC and cobalamin were calculated. Results The majority of patients fell within the age group of 20-70 years, with 57% of them being females and 43% males; Holo-TC exhibited a sensitivity of 98.9% and specificity of 50.00%, with a PPV of 98.90% and NPV of 50%. Vitamin B12 demonstrated a sensitivity of 63% and specificity of 50%, with a PPV of 98.33% and NPV of 2.85%. The diagnostic accuracy of Holo-TC and vitamin B12 was observed to be 97.8% and 63%, respectively. Conclusions Between the two, Holo-TC displays higher diagnostic accuracy than vitamin B12 and can serve as the primary test for patients suspected of having vitamin B12 deficiency.

The application and interpretation of laboratory biomarkers for the evaluation of vitamin B12 status.

Vitamin B12 (cobalamin; B12) is an essential micronutrient, but deficiency is common. The prompt diagnosis and treatment of B12 deficiency protects against megaloblastic anaemia, neuropathy and neuropsychiatric changes. Biomarkers of B12 status include the measurement of serum B12 (also known as total B12 or serum cobalamin), holotranscobalamin (holoTC or 'active B12'), methylmalonic acid (MMA) and total plasma homocysteine (Hcy). There is no 'gold standard' test for deficiency and the sensitivity and specificity of each biomarker for the evaluation of B12 status is affected by analytical and biological factors that may confer a high degree of diagnostic uncertainty. Limited access to technical and clinical expertise can lead to an over-reliance on the serum B12 test, which is readily available and highly automated. In some cases, the sequential use of different B12 status biomarkers or the calculation of a composite B12 status score, derived from a panel of B12 biomarkers and adjusted for folate status and age, can be used to detect deficient states that may otherwise be overlooked when using a single biomarker approach. This review summarises the utility of B12-related biomarkers and describes approaches to their application and interpretation.

Effect of oral or subcutaneous administration of cyanocobalamin in hypocobalaminemic cats with chronic gastrointestinal disease or exocrine pancreatic insufficiency.

No prospective study has evaluated the efficacy of oral supplementation with cobalamin in hypocobalaminemic cats. To investigate the efficacy of oral or SC supplementation with cyanocobalamin in normalizing serum cobalamin and methylmalonic acid (MMA) concentrations in hypocobalaminemic cats with chronic gastrointestinal disease (CGID) or exocrine pancreatic insufficiency (EPI). Forty-eight client-owned hypocobalaminemic (<290 ng/L) cats with normal or abnormally high serum MMA concentrations. This study was conducted based on the prospective randomized clinical trial method. Cats with CGID or EPI were randomly assigned to 2 groups that received either oral or SC supplementation with cobalamin (250 μg/cat) for 12 and 10 weeks, respectively, in addition to other medical and dietary interventions. Each cat was evaluated 3 times (baseline, 6-week postsupplementation, and 1-week postcompletion) by measuring serum cobalamin and MMA concentrations. In cats with CGID or EPI, cobalamin concentrations were normalized in all cats that received either oral or SC supplementation (mean 100% [95% CI: 80.6%-100%] in both groups in cats with CGID and 100% [67.6%-100%] in both groups in cats with EPI). Among 37 cats with elevated MMA concentrations at baseline (21 cats with CGID and 16 cats with EPI), MMA concentrations were normalized in most cats with CGID (70% in oral and 82% in SC group) or EPI (88% in both groups). In hypocobalaminemic cats with CGID or EPI, in conjunction with other medical and dietary interventions, both oral and SC supplementation are effective at normalizing serum cobalamin and MMA concentrations.

Implications of hypocobalaminemia as a negative prognostic marker in juvenile dogs with parvovirus enteritis.

Canine Parvovirus 2 (CPV-2) infection poses a significant global health risk to susceptible dogs. Hypocobalaminemia, defined as reduced serum cobalamin (CBL) concentrations, is a recognized complication in chronic enteropathies in adult dogs but remains poorly understood in the context of acute enteropathies, especially in young dogs. The aim of this study was to investigate the frequency and severity of hypocobalaminemia in young dogs with parvovirus enteritis and evaluation of CBL as a predictor of outcome. Thirty client-owned dogs diagnosed with parvovirus infection and thirty healthy controls were enrolled. Clinical, hematological, and biochemical tests, including CBL and serum methylmalonic acid (MMA) concentrations, were assessed. Results indicated a significantly higher prevalence of hypocobalaminemia in dogs with parvovirus enteritis compared to healthy controls, as well as a significant correlation with a disease severity score. Moreover, survivors demonstrated higher CBL concentrations than non-survivors, suggesting an eventual prognostic value of CBL status. However, parenteral CBL supplementation showed no significant effect on serum CBL or MMA concentrations, highlighting potential challenges in CBL uptake at the cellular level. Hypocobalaminemia in this population is caused by multiple factors such as reduced nutritional absorption, gastrointestinal losses, and increased metabolic demands. Further research is needed to develop tailored management strategies, evaluate the effectiveness of CBL supplementation, and understand the mechanisms behind hypocobalaminemia in parvovirus infection.

Decreased cobalamin sensitivity and biological aging acceleration in the general population

BackgroundThe evidence on the association between cobalamin (Cbl) and aging or relevant outcomes is limited and controversial. We aimed to investigate the relationships between cobalamin intake- and function-related biomarkers and biological aging. MethodsThe study encompassed 22,812 participants aged 20 years and older from the National Health and Nutrition Examination Survey. A panel of biomarkers or algorithms was used to assess biological aging, including Klemera–Doubal Age Acceleration (KDMAccel), Phenotypic age acceleration (PhenoAgeAccel), telomere length, α-Klotho, and PhenoAge advancement. Weighted generalized linear regression analysis was used to assess the associations between cobalamin-intake biomarkers (serum cobalamin, cobalamin intake from food, cobalamin supplement use, serum methylmalonic acid [MMA], and homocysteine [Hcy]) and function-related biomarkers (functional cobalamin deficiency and cobalamin insensitivity index). ResultsAmong the 22,812 individuals, the weighted mean (SE) age was 48.3 (0.2) years and 48.0% were males. Unexpectedly, serum and dietary cobalamin as well as serum MMA and Hcy levels were positively associated with most indicators of biological aging. Cobalamin sensitivity was assessed by the combination of binary Cbllow/high and MMAlow/high or Hcylow/high (cutoff values: 400 pg/mL for cobalamin, 250 nmol/L for MMA, and 12.1 μmol/l for Hcy) and a newly constructed cobalamin insensitivity index (based on the multiplicative term of serum cobalamin and serum MMA or Hcy). The multivariable-adjusted β (95%CIs) of KDMAccel in the MMAlowCbllow, MMAlowCblhigh, MMAhighCbllow, and MMAhighCblhigh groups were reference, 0.27 (0.03 to 0.51), 0.85 (0.41 to 1.29), and 7.97 years (5.77 to 10.17) respectively, which were consistent for the combination of serum Hcy and cobalamin. Both cobalamin insensitivity indices were robustly associated with biological aging acceleration in a dose-response pattern (each p < 0.001). ConclusionsDecreased cobalamin sensitivity but not cobalamin insufficiency might be associated with biological aging acceleration. Further studies would improve understanding of the underlying mechanisms between decreased cobalamin sensitivity and biological aging acceleration.

Prognostic potential of copper, zinc, copper/zinc ratio, cobalamin, and serum amyloid A in cats with panleukopenia.

Copper (Cu), zinc (Zn), and the copper/zinc ratio (Cu/Zn), which have been studied in gastrointestinal disorders of humans, may facilitate disease prognosis. Evaluate the predictive potential of Cu, Zn, cobalamin, and serum amyloid A (SAA) as prognostic indicators in cats with feline panleukopenia (FPV) on admission. Client-owned cats diagnosed with FPV and controls. Serum Cu and Zn concentrations were assessed using the spectrophotometric method and serum concentrations of SAA and cobalamin were measured by chemiluminescent immunoassay. On admission, survivor cats with FPV had significantly higher serum Cu and SAA concentrations and Cu/Zn ratios and significantly lower serum Zn and cobalamin concentrations than controls. Furthermore, non-survivor cats with FPV had significantly higher serum Cu and SAA concentrations and Cu/Zn ratios and significantly lower cobalamin concentrations than survivors and controls. Prognostic thresholds were calculated, with positive predictive value (PPV) for survival of 90% for Cu (≥120.3 μg/dL), 90% for Cu/Zn (≥1.34), 90% for cobalamin (≤430.4 pg/mL), and 90% for SAA (≥0.85 mg/L). Cu (0.93 area under curve [AUC]), Cu/Zn (0.95 AUC), cobalamin (0.98 AUC), and SAA (0.98 AUC) were excellent biomarkers for predicting prognosis in cats with FPV. Their effectiveness, as assessed by sensitivity (100%), specificity (80%), AUC (0.98), and PPV (90%) from receiver operating characteristic analysis, emphasizes the performance of cobalamin and SAA.

The effect of feeding on serum concentrations of cobalamin, folate, trypsin-like immunoreactivity, and pancreatic lipase immunoreactivity in dogs with signs of chronic gastrointestinal disease.

It is unknown if serum concentrations of cobalamin, folate, canine pancreatic lipase immunoreactivity (cPLI), and canine trypsin-like immunoreactivity (cTLI) obtained postprandially are equivalent to measurements obtained after withholding food in dogs with suspected gastrointestinal disease. Measurements of serum concentrations of cobalamin, folate, cPLI, and cTLI postprandially will be equivalent to measurements after 12 hours of withholding food in dogs with signs of chronic gastrointestinal disease. Changes observed will not alter clinical interpretation. 51 client-owned dogs with signs of gastrointestinal disease. Prospective single arm clinical trial. Serum concentrations of cobalamin, folate, cPLI and cTLI 2, 4, and 8 hours postprandially were compared by equivalence testing to values after withholding food for 12 hours (baseline). Mean serum cobalamin concentrations 2 hours (498.1 ± 213.1 ng/L; P = 0.024) and 4 hours (501.9 ± 207.4 ng/L; P = 0.008) postprandial were equivalent to baseline (517.3 ± 211.5 ng/L). Mean serum cTLI 2 hours (31.3 ± 14 μg/L; P < 0.001) and 4 hours (29.6 ± 13.1 μg/L; P = 0.027) postprandial were equivalent to baseline (31.1 ± 15 μg/L). Mean serum folate concentration 2 hours postprandial (15 ± 7.7 μg/L) was equivalent to baseline (13.7 ± 8.3 μg/L; P < 0.001). Equivalence could not be assessed for cPLI due to results below the lower limit of quantification. Feeding altered the clinical interpretation in 27% (cobalamin), 35% (folate), 20% (cTLI), and 12% (cPLI) of dogs. The clinical interpretation for a substantial number of samples changed after feeding, therefore withholding food before sample collection is prudent.

The association between serum methylmalonic acid, cobalamin-related biomarkers, and long-term mortality risk in cancer survivors: a prospective cohort study

BackgroundElevated serum methylmalonic acid (MMA), a marker of cobalamin (vitamin B12) deficiency, has been linked to cancer progression. However, the impact of MMA or cobalamin on mortality risk in cancer survivors remains unknown. ObjectivesTo explore the relationship between MMA, serum, dietary, and supplement of cobalamin, MMA metabolism-related genes, and poor prognosis in adult cancer survivors. MethodsWe analyzed data from 1988 cancer survivors aged ≥20 y. Patients were selected from the National Health and Nutrition Examination Survey and followed up until December 31, 2019. Weighted Cox proportional hazard regression was used to estimate hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) for mortality risk assessment. Genomic analysis identified MMA metabolism-related genes linked to early death in a 33-cancer-type cohort from The Cancer Genome Atlas. ResultsAmong 1988 participants, 872 deaths occurred over a 10-year follow-up. Higher serum MMA levels were significantly linked to increased long-term mortality risk (tertile 3 compared with tertile 1: adjusted HR: 1.37; 95% CI: 1.11, 1.70; P-trend < 0.001). No associations were found between serum, dietary, and supplement of cobalamin and cancer survivor mortality (each P-trend > 0.143). However, MMA-associated mortality was notable in patients without deficiency. When combining cobalamin and MMA categories, multivariate-adjusted HR (95% CI) for all-cause mortality was 2.06 (95% CI: 1.60, 2.65) in participants with >250 nmol/L and cobalamin >295.1 pmol/L compared with those with MMA ≤250 nmol/L and cobalamin >295.1 pmol/L. Moreover, reduced transcriptional levels of MMA metabolism-related genes, indicating decreased mitochondrial MMA metabolism capability, are linked to an unfavorable prognosis in certain cancer types. ConclusionsSerum MMA was associated with long-term mortality risk in adult cancer survivors, which was more significant among individuals with higher levels of serum cobalamin. These findings suggest that mortality related to MMA was attributed to the insufficient flux of MMA metabolism, not cobalamin deficiency.

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.

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

Pediatric reference intervals for serum folate and cobalamin based on a European population without exposure to folic acid fortification

The aim of the present study was to define pediatric reference intervals for serum cobalamin and folate utilizing data generated from a population not exposed to food fortified with folic acid. Folate and cobalamin results analyzed by electrochemiluminescence immunoassay (Roche Cobas) were obtained from 2375 children (2 months to 17.99 years of age). The serum samples were collected between 2011 and 2015 as part of the LIFE (Leipzig Research Centre for Civilization Diseases) Child cohort study in Germany, where folic acid fortification of food is not mandated. These results were used to generate age- and gender-specific reference intervals presented as non-parametric 2.5 and 97.5 percentiles. Because of a subsequent restandardisation of the Roche folate assay in 2016, folate values were recalculated accordingly for adaptation to results obtained using the present calibration. In both genders, folate concentrations decreased continuously with age, whereas cobalamin concentrations peaked at five years of age and then declined. Teenage females had higher concentrations of cobalamin in the age group 12–17.99 years.

Efficacy and tolerance of oral versus parenteral cyanocobalamin supplement in hypocobalaminaemic dogs with chronic enteropathy: a controlled randomised open-label trial.

Determine comparative tolerance of daily oral and weekly parenteral cobalamin supplementation, in hypocobalaminaemic dogs with chronic enteropathy. Determine whether oral is as effective as parenteral supplementation at achieving eucobalaminaemia, in hypocobalaminaemic dogs with protein-losing enteropathy, severe hypocobalaminaemia or high canine inflammatory bowel disease activity index at inclusion. Thirty-seven client-owned dogs with hypocobalaminaemia and clinical signs of chronic enteropathy were prospectively enrolled in three UK referral centres. Dogs were randomly allocated to daily oral for 12 weeks or weekly parenteral cobalamin supplementation for 6 weeks and one additional dose 4 weeks later. Serum cobalamin, body condition score, canine inflammatory bowel disease activity index and bodyweight were assessed at inclusion, weeks 7 and 13. Serum methylmalonic acid concentration was evaluated at inclusion and at week 13. Owners completed treatment adherence, palatability, tolerance and satisfaction questionnaires at week 13. Nineteen dogs completed the study. All dogs orally supplemented achieved normal or increased cobalaminaemia at weeks 7 and 13. There was no statistical difference in cobalamin concentration at week 13 in dogs treated with oral or parenteral supplementation, regardless of presence of protein-losing enteropathy, severity of hypocobalaminaemia or canine inflammatory bowel disease activity index at inclusion. Serum methylmalonic acid concentration was not significantly different between oral and parenteral groups, neither were treatment adherence, satisfaction, and tolerance scores at week 13. Oral is as effective and as well-tolerated as parenteral cobalamin supplementation in hypocobalaminaemic dogs with chronic enteropathy and severe clinical or biochemical phenotypes, and should be considered as a suitable treatment option regardless of disease severity.

Expression of the cobalamin transporters cubam and MRP1 in the canine ileum-Upregulation in chronic inflammatory enteropathy.

Chronic inflammatory enteropathy (CIE) in dogs, a spontaneous model of human inflammatory bowel disease (IBD), is associated with a high rate of cobalamin deficiency. The etiology of hypocobalaminemia in human IBD and canine CIE remains unknown, and compromised intestinal uptake of cobalamin resulting from ileal cobalamin receptor deficiency has been proposed as a possible cause. Here, we evaluated the intestinal expression of the cobalamin receptor subunits, amnionless (AMN) and cubilin (CUBN), and the basolateral efflux transporter multi-drug resistance protein 1 (MRP1) in 22 dogs with CIE in comparison to healthy dogs. Epithelial CUBN and AMN levels were quantified by confocal laser scanning microscopy using immunohistochemistry in endoscopic ileal biopsies from dogs with (i) CIE and normocobalaminemia, (ii) CIE and suboptimal serum cobalamin status, (iii) CIE and severe hypocobalaminemia, and (iv) healthy controls. CUBN and MRP1 expression was quantified by RT-qPCR. Receptor expression was evaluated for correlation with clinical patient data. Ileal mucosal protein levels of AMN and CUBN as well as mRNA levels of CUBN and MRP1 were significantly increased in dogs with CIE compared to healthy controls. Ileal cobalamin receptor expression was positively correlated with age, clinical disease activity index (CCECAI) score, and lacteal dilation in the ileum, inversely correlated with serum folate concentrations, but was not associated with serum cobalamin concentrations. Cobalamin receptor downregulation does not appear to be the primary cause of hypocobalaminemia in canine CIE. In dogs of older age with severe clinical signs and/or microscopic intestinal lesions, intestinal cobalamin receptor upregulation is proposed as a mechanism to compensate for CIE-associated hypocobalaminemia. These results support oral supplementation strategies in hypocobalaminemic CIE patients.

Relationship between Serum Cobalamin Levels and Disease Severity in COVID-19 Patients

Background and Objective: Vitamins play a crucial role in cellular growth, function, and evolution. Additionally, they contribute significantly to pathogen defense through cellular responses and immune enhancement. Cobalamin has been identified to play a role in suppressing virus replication, generating anti-inflammatory responses, and boosting immunity in infected patients with COVID-19. Therefore, we hypothesized that the low cobalamin levels are associated with a predisposition to severe COVID-19 infection. The present study aimed to investigate the relationship between cobalamin levels and disease severity and prognosis in COVID-19 patients. Materials and Methods: This cross-sectional study included 117 COVID-19 patients hospitalized at Sina Hospital and categorized them into three groups based on their disease severity: mild to moderate, severe, and critical. Demographic information and clinical findings of the patients were recorded. Serum cobalamin levels were assessed using biochemical methods. Logistic regression and Receiver Operating Characteristic (ROC) analyses were employed for mortality prediction based on serum cobalamin levels. Results: The results revealed that patients with low cobalamin levels are more susceptible to severe COVID-19 infections. Furthermore, with each additional day of hospitalization, the mortality rate due to COVID-19 increased by 24%. The high area under the ROC curve (0.837) indicated that mortality in COVID-19 patients can be effectively predicted based on cobalamin levels. Conclusion: It appears that cobalamin supplementation may have positive effects on COVID-19 patients’ outcomes. Additionally, serum cobalamin levels serve as a valuable indicator for predicting the mortality rate in COVID-19 patients. However, comprehensive, longer-term studies with a larger number of patients are required.

Hypocobalaminaemia in dogs with acute gastrointestinal diseases.

The objectives of this study were to investigate the prevalence of hypocobalaminaemia in dogs with acute gastrointestinal diseases and to evaluate its relationship with disease severity and outcome. Medical records of dogs presented for acute gastrointestinal signs that a serum cobalamin concentration measured between September 2019 and 2021 were included in this study. Hypocobalaminaemia was defined as serum cobalamin concentration <200 pmol/L, and low-normal cobalamin was defined as serum cobalamin concentration of 200 to 295 pmol/L. Duration of clinical signs prior to presentation, Acute Patient Physiologic and Laboratory Evaluation (APPLE) fast score, length of hospitalisation and outcome were recorded. Thirty-three dogs were included. Seventeen dogs were diagnosed with acute gastrointestinal disease of unknown aetiology, seven dogs with parvoviral enteritis, three dogs with acute haemorrhagic diarrhoea syndrome and six dogs with miscellaneous diseases. The prevalence of hypocobalaminaemia in this population was 30.3% and low-normal cobalamin concentration was detected in 18.2% of dogs. There was no statistically significant relationship between the detection of hypocobalaminaemia or low-normal cobalamin and the duration of clinical signs before presentation, length of hospitalisation or Acute Patient Physiologic and Laboratory Evaluation fast score on admission. Mortality rate was 3%. Hypocobalaminaemia and low-normal cobalamin are common findings in dogs with acute gastrointestinal diseases. The therapeutic significance and potential implications for prognosis of hypocobalaminaemia in these patients requires further investigation.

Intestinal Biomarkers and Their Importance in Canine Enteropathies

Enteropathies are prevalent in dog internal medicine, and their diagnosis involves a lengthy process. One of the tests requested is for biomarkers, which are important as they can provide data on intestinal functionality, intensity of inflammation, and response to treatment, and can help determine the prognosis. This study aimed to conduct a literature review on the main serum and fecal intestinal biomarkers in dogs and proposed to refine the correlations between these indicators and enteropathies. It was observed that the main biomarkers used in the intestinal evaluation of dogs were alpha 1‐proteinase inhibitory factor, immunoglobulin A, methylmalonic acid, serum folate, serum cobalamin, C‐reactive protein, fecal and serum calprotectin, and dysbiosis index. However, we suggest that more research be carried out to clarify the relationship between enteropathies and intestinal biomarkers. We noticed a lack of studies on specific intestinal markers and indicator variables in healthy dogs and those with various enteropathies; moreover, no data are available on the association of these laboratory parameters.

Chronic Inflammatory Enteropathy and Low-Grade Intestinal T-Cell Lymphoma Are Associated with Altered Microbial Tryptophan Catabolism in Cats.

Chronic inflammatory enteropathy (CIE) and low-grade intestinal T-cell lymphoma (LGITL) are common chronic enteropathies (CE) in cats. Enteric microbiota dysbiosis is implicated in the pathogenesis of CE; however, the mechanisms of host-microbiome interactions are poorly understood in cats. Microbial indole catabolites of tryptophan (MICT) are gut bacterial catabolites of tryptophan that are hypothesized to regulate intestinal inflammation and mucosal barrier function. MICTs are decreased in the sera of humans with inflammatory bowel disease and previous studies identified altered tryptophan metabolism in cats with CE. We sought to determine whether MICTs were decreased in cats with CE using archived serum samples from cats with CIE (n = 44) or LGITL (n = 31) and healthy controls (n = 26). Quantitative LC-MS/MS was used to measure serum concentrations of tryptophan, its endogenous catabolites (kynurenine, kynurenate, serotonin) and MICTs (indolepyruvate, indolealdehyde, indoleacrylate, indoleacetamide, indoleacetate, indolelactate, indolepropionate, tryptamine). Serum concentrations of tryptophan, indolepropionate, indoleacrylate, indolealdehyde, indolepyruvate, indolelactate were significantly decreased in the CIE and LGITL groups compared to those in healthy controls. Indolelactate concentrations were significantly lower in cats with LGITL compared to CIE (p = 0.006). Significant correlations were detected among serum MICTs and cobalamin, folate, fPLI, and fTLI. Our findings suggest that MICTs are promising biomarkers to investigate the role of gut bacteria in the pathobiology of chronic enteropathies in cats.

Low Levels of Serum Total Vitamin B12 Are Associated with Worse Metabolic Phenotype in a Large Population of Children, Adolescents and Young Adults, from Underweight to Severe Obesity

Vitamin B12 (or cobalamin) is an essential vitamin for DNA synthesis, fatty acid and protein metabolism as well as other metabolic pathways fundamental to the integrity of cells and tissues in humans. It is derived from the diet and mostly stored in the liver. Its deficiency has been associated with metabolic derangements, i.e., obesity, glucose intolerance, increased lipogenesis and metabolic dysfunction-associated steatotic liver disease (MASLD) and steatohepatitis (MASH). However, data with regard to body weight across the whole spectrum (from underweight to severe obesity) in children and young individuals are scarce. The present study aims to describe the association between serum total vitamin B12 and body mass index (BMI) ranging from underweight to severe obesity in a large population of children, adolescents and young adults. This study also investigates associations with visceral adiposity, glucose and lipid metabolism and liver dysfunction. A cross-sectional, single-centre study was conducted at the Paediatrics and Endocrinology units of the ”Bambino Gesù Children Hospital”, a tertiary referral institution for eating disorders. Clinical charts were reviewed and 601 patients aged from 5 to 25 years were enrolled in order to analyse anthropometric, auxological, clinical, biochemical and liver ultrasound data using robust statistical approaches. Analyses were adjusted for potential confounders. A reduction in serum total B12 levels was associated with a linear increase in body weight, as expressed by WHO BMI SDS (r = −0.31, p &lt; 0.001, BCa 95% −0.38, −0.24). Lower B12 levels were associated with higher waist circumference but only in pubertal girls (r = −0.33, p = 0.008, BCa 95% −0.53, −0.11). Hepatic insulin resistance was higher in males with lower B12 levels (B = −0.003 (−0.007, −0.0001), p = 0.039), but not in females, whereas whole-body insulin resistance was unaffected. Serum lipid profiles (total, HDL and LDL cholesterol and triglycerides) were not influenced by serum cobalamin levels. However, lower cobalamin levels were associated with higher grading of ultrasound-scored hepatic steatosis (ptrend = 0.035). Lastly, both AST and ALT showed a significant and direct correlation with total B12 levels in underweight (r = 0.22 and 0.24, p = 0.002 and &lt;0.001, respectively) and severely obese subjects (r = 0.24 and 0.32, p = 0.002 and &lt;0.001). In conclusion lower vitamin B12 levels are associated with higher body weight, adiposity and with worse metabolic health in a large population of children, adolescents and young adults.

S1185 Disease Localization and Use of Proton Pump Inhibitors as Predictors of Serum Cobalamin and Vitamin D Status in Patients With Inflammatory Bowel Disease

S1185 Disease Localization and Use of Proton Pump Inhibitors as Predictors of Serum Cobalamin and Vitamin D Status in Patients With Inflammatory Bowel Disease

Randomized controlled trial of hydrolyzed fish diets in dogs with chronic enteropathy.

The role of diet in the pathogenesis and treatment of chronic enteropathies (CE) in dogs is unresolved. To compare the ability of diets composed of hydrolyzed fish, rice starch, and fish oil without (HF) or with prebiotics, turmeric, and high cobalamin (HF+) against a limited ingredient diet containing mixed nonhydrolyzed antigens and oils (control) to resolve clinical signs and maintain serum cobalamin and folate concentrations in dogs with nonprotein losing CE (non-PLE). To determine the ability of hydrolyzed fish diets to support recovery and remission in dogs with PLE. Thirty-one client-owned dogs with CE: 23 non-PLE, 8 PLE. Randomized, blinded, controlled trial. Diets were fed for 2 weeks; responders continued for 12 weeks. Nonresponders were crossed over to another diet for 12 weeks. Response was determined by standardized clinical evaluation with long-term follow-up at 26 weeks. Concurrent medications were allowed in PLE. Nineteen of 23 (83%; 95% confidence interval [CI], 60%-94%) non-PLE CE responded clinically to their initial diet, with no difference between diets (P > .05). Four nonresponders responded to another diet, with sustained remission of 18/18 (100%; 95%CI, 78%-100%) at 26 weeks. Serum cobalamin concentration was increased (P < .05) and maintained by diet. Serum folate concentration decreased posttreatment (P < .05) but was restored by dietary supplementation. Hydrolyzed fish diets supported weight gain, serum albumin concentration, and recovery (P < .05) in dogs with PLE. Changing diet, independent of antigen restriction or supplemental ingredients, induced long-term remission in dogs with non-PLE CE. Serum cobalamin and folate concentrations were maintained by diet. Hydrolyzed fish diets supported clinical recovery and remission in PLE.