Etiology, Clinical Manifestations, Diagnosis, and Treatment of Cobalamin (Vitamin B12) Deficiency.

Cobalamin, also known as vitamin B12, is a water-soluble vitamin. Cobalamin deficiency can be frequently seen in people all around the world. It can have non-specific symptoms, and in patients who are in a very critical state, it can lead to neurological or hematological abnormalities. While pernicious anemia used to be the main cause, it now accounts for a smaller number of cases, with food-bound cobalamin malabsorption being more common. Early diagnosis and appropriate management are crucial to avoid severe complications like spinal cord degeneration and pancytopenia. The primary method of treatment has been injections of vitamin B12 which are given through the intramuscular route but now the oral replacement therapy has also been very effective in treating the patients. There is increasing evidence linking increased levels of vitamin B12 to hematological and hepatic disorders, particularly cancers. This review has primarily highlighted the metabolism, clinical manifestations, diagnosis, and treatment of cobalamin deficiency in the past decade.

An update on VEXAS syndrome.

INTRODUCTION: VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a recently described, late-onset, acquired autoinflammatory disorder caused by mutations in the UBA1 gene. The various clinical manifestations of VEXAS broadly divided into inflammatory or haematological. VEXAS defines a new disease category - the hematoinflammatory disorders triggered by somatic mutations restricted to blood but causing systemic inflammation with multi-organ involvement and associated with aberrant bone marrow status. VEXAS causes significant morbidity and reduced life expectancy, but the optimum standard of care remains undefined. AREAS COVERED: This review describes the discovery of VEXAS, relevant genetic causes and immunopathology of the disease. A detailed account of its various clinical manifestations and disease mimics is provided. Current treatment and management options are discussed. EXPERT OPINION: New rare variants in UBA1 and VEXAS-like UBA1 negative cases are reported. Consensus diagnostic criteria might be required to define VEXAS and its related disorders. Investigation of sporadic, VEXAS-like cases will require the application of deep sequencing using DNA obtained from various cellular or tissue locations. Prospective studies are needed to define the optimal supportive and treatment options for patients with varying disease severity and prognosis. VEXAS-specific hematopoietic stem cell transplant selection criteria also require development.

The Effects of Proton Pump Inhibitors in Acid Hypersecretion-Induced Vitamin B12 Deficiency: A Systematic Review (2022).

Gastroesophageal reflux disease (GERD) is the most common disease, for which proton pump inhibitors (PPIs) are a widely used class of drugs. Due to their efficacy and relative safety profile, PPIs are used chronically by GERD patients. Although it is a safe drug, particular attention focuses on the long-term adverse effects of PPI. The association with vitamin deficiencies has received additional focus since chronic PPI treatment increases the incidence of vitamin B12 deficiency, especially in the elderly. However, numerous studies regarding the establishment of an association between PPI and vitamin B12 status revealed conflicting results. In this systematic review, we systematically examined observational studies that focused on the impact of chronic PPI effects on vitamin B12 absorption and diagnostic biomarkers of vitamin B12 deficiency. Our review showed significant changes in diagnostic biomarkers of vitamin B12 status in long-term PPI users, including elevated homocysteine and methylmalonic acid (MMA) concentration levels defining cellular vitamin B12 deficiency. Although there is uncertainty regarding the exact mechanism, it supports the concept that long-term intake of PPI can have clinical implications for vitamins.

VEXAS syndrome: lessons learnt from an early Australian case series.

VEXAS is a newly recognised adult-onset autoinflammatory syndrome resulting from a somatic mutation in the UBA1 gene. Herein, we present three cases of VEXAS syndrome in Sydney, Australia, that capture key clinical features and the refractory nature of the condition. They highlight the importance of multidisciplinary collaboration for early diagnosis and the need for new therapeutic options.

Macrocytic Anaemia: Not Always a Straightforward Diagnosis.

Macrocytosis is defined as a mean corpuscular volume greater than 100 femtolitres (fL). There are several causes for macrocytic anaemia, and they can be divided into megaloblastic or non-megaloblastic anaemia. Vitamin B12 deficiency is one of the most common causes of megaloblastic anaemia. The cause of vitamin B12 deficiency must be evaluated including the presence of pernicious anaemia as it could alter the treatment and follow-up. Pernicious anaemia can be associated with other autoimmune diseases constituting polyglandular syndromes.

Prevalence of potential underlying aetiology of macrocytic anaemia in Dutch general practice.

BACKGROUND: Macrocytic anaemia (MCV ≥ 100 fL) is a relatively common finding in general practice. However, literature on the prevalence of the different causes in this population is limited. The prevalence of macrocytic anaemia and its underlying aetiology were analysed in a general practice population. The potential effect of the different aetiology on survival was also evaluated. METHODS: Between the 1st of February 2007 and the 1st of February 2015, patients aged 50 years or older and presenting to their general practitioner with a newly diagnosed anaemia, were included in the study. Anaemia was defined as haemoglobin level below 13.7 g/dL in men and below 12.1 g/dL in women. A broad range of laboratory tests was performed for each patient. The causes of anaemia were consequently determined by two independent observers based on the laboratory results. RESULTS: Of the 3324 included patients, 249 (7.5 %) displayed a macrocytic anaemia and were subsequently analysed. An underlying explanation could be established in 204 patients (81.9 %) with 27 patients (13.2 %) displaying multiple causes. Classic aetiology (i.e. alcohol abuse, vitamin B12/folic acid deficiency, haemolysis and possible bone marrow disease) was found in 115 patients. Alternative causes (i.e. anaemia of chronic disease, iron deficiency, renal anaemia and other causes) were encountered in 101 patients. In addition, a notable finding was the median gamma GT of 277 U/L in patients diagnosed with alcohol abuse (N = 24, IQR 118.0-925.5) and 23 U/L in the remaining cohort (N = 138, IQR 14.0-61.0). The distribution of gamma GT values was statistically different (P < 0.001). Five year survival rates were determined for six categories of causes, ranging from 39.9 % (95 % CI 12.9-66.9) for renal anaemia to 76.2 % (95 % CI 49.4-103.0) for the category multiple causes. CONCLUSION: In addition to classic explanations for macrocytosis, alternative causes are frequently encountered in patients with macrocytic anaemia in general practice.