Predicting MacroB12: Data-Driven Assessment of Pre-PEG B12 Utility and Clinical Caveats

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Frías-Ruiz, Carmen, Gálvez-Navas, José María, García-Calcerrada, Isabel, Flórez, Silvia Heras, Fabregas, Rene
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866917033610838016
author Frías-Ruiz, Carmen
Gálvez-Navas, José María
García-Calcerrada, Isabel
Flórez, Silvia Heras
Fabregas, Rene
author_facet Frías-Ruiz, Carmen
Gálvez-Navas, José María
García-Calcerrada, Isabel
Flórez, Silvia Heras
Fabregas, Rene
contents MacroB12 interference presents a significant challenge in the diagnosis of Vitamin B12 status, potentially masking true deficiency. To establish robust predictors and quantify the utility of pre-polyethylene glycol (PEG) B12 levels, we conducted a retrospective analysis of 875 individuals with hypercobalaminaemia (greater than 1000 pg/mL), using multiple imputation to handle missing data. Multivariable regression modelling revealed that MacroB12 positivity (less than 30% PEG recovery) was independently associated with a profile suggestive of autoimmunity, including older age (adjusted odds ratio [aOR] 1.03 per year, P<0.001) and a Rheumatologic/Autoimmune diagnosis (aOR 2.96, P=0.01). We also identified a counterintuitive haematological signature, with higher haemoglobin (aOR 1.14, P=0.02) and Mean Corpuscular Volume (aOR 1.04, P=0.01) predicting MacroB12. Receiver Operating Characteristic (ROC) analysis of pre-PEG B12 concentration yielded only moderate discriminatory power (Area Under the Curve [AUC] = 0.744, 95% CI 0.707-0.782). The optimal threshold of 1584.0 pg/mL (sensitivity 71.3%, specificity 69.7%) serves to stratify clinical suspicion, but its performance confirms that it cannot replace definitive confirmatory testing. Our findings define a clinical and laboratory phenotype for suspected MacroB12 but highlight that confirmatory PEG precipitation remains essential for accurate diagnosis, particularly in older patients and those with autoimmune disease.
format Preprint
id arxiv_https___arxiv_org_abs_2510_00178
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Predicting MacroB12: Data-Driven Assessment of Pre-PEG B12 Utility and Clinical Caveats
Frías-Ruiz, Carmen
Gálvez-Navas, José María
García-Calcerrada, Isabel
Flórez, Silvia Heras
Fabregas, Rene
Quantitative Methods
Data Analysis, Statistics and Probability
62P10 (Primary), 62H30 (Secondary), 68T05 (Secondary), 00A71 (Secondary)
MacroB12 interference presents a significant challenge in the diagnosis of Vitamin B12 status, potentially masking true deficiency. To establish robust predictors and quantify the utility of pre-polyethylene glycol (PEG) B12 levels, we conducted a retrospective analysis of 875 individuals with hypercobalaminaemia (greater than 1000 pg/mL), using multiple imputation to handle missing data. Multivariable regression modelling revealed that MacroB12 positivity (less than 30% PEG recovery) was independently associated with a profile suggestive of autoimmunity, including older age (adjusted odds ratio [aOR] 1.03 per year, P<0.001) and a Rheumatologic/Autoimmune diagnosis (aOR 2.96, P=0.01). We also identified a counterintuitive haematological signature, with higher haemoglobin (aOR 1.14, P=0.02) and Mean Corpuscular Volume (aOR 1.04, P=0.01) predicting MacroB12. Receiver Operating Characteristic (ROC) analysis of pre-PEG B12 concentration yielded only moderate discriminatory power (Area Under the Curve [AUC] = 0.744, 95% CI 0.707-0.782). The optimal threshold of 1584.0 pg/mL (sensitivity 71.3%, specificity 69.7%) serves to stratify clinical suspicion, but its performance confirms that it cannot replace definitive confirmatory testing. Our findings define a clinical and laboratory phenotype for suspected MacroB12 but highlight that confirmatory PEG precipitation remains essential for accurate diagnosis, particularly in older patients and those with autoimmune disease.
title Predicting MacroB12: Data-Driven Assessment of Pre-PEG B12 Utility and Clinical Caveats
topic Quantitative Methods
Data Analysis, Statistics and Probability
62P10 (Primary), 62H30 (Secondary), 68T05 (Secondary), 00A71 (Secondary)
url https://arxiv.org/abs/2510.00178