Clinical picture and diagnostics of vitamin B12 deficiency in children.

Brakema, L. (Liesanne) (2015) Clinical picture and diagnostics of vitamin B12 deficiency in children. thesis, Medicine.

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Abstract

Background Vitamin B12 deficiency in children may be more common than realised. Diagnostics of vitamin B12 deficiency in children is challenging. Vitamin B12 deficiency in children can present with classic neurological & psychiatric manifestations and macrocytic anaemia, but it can also present with non-specific symptoms, which have a limited diagnostic precision. Also, when it comes to the parameters to test vitamin B12 deficiency; vitamin B12, MMA, homocysteine and HoloTC, there is no diagnostic golden standard to establish the diagnosis. In addition, cut off values of these parameters vary widely and the sensitivities and specificities for these tests in children are not yet determined. Methods We investigated children with suspected vitamin B12 deficiency (n=74, aged 1- 17 years). We established the diagnosis vitamin B12 deficiency by the clinical picture of the patients, all the parameters of vitamin B12 deficiency (vitamin B12, MMA, homocysteine (tHcy) and HoloTC), the judgement of the treating physician and the effect of treatment. In the patients with established vitamin B12 deficiency we investigated the symptoms and looked for causes of vitamin B12 deficiency. To estimate the accuracy of the different tests, we performed ROC curve analyses for vitamin B12, MMA, tHcy and HoloTC and calculated the sensitivity and specificity of these tests in children with suspected vitamin B12 deficiency. We looked for significant correlations between the parameters and we also investigated if there was a correlation between age and the parameters in children with suspected vitamin B12 deficiency. Results We found that in patients with established vitamin B12 deficiency the most reported symptoms were: fatigue, stomach ache/nausea/vomiting, head ache, decreased physical performance, concentration problems/ memory loss, pain in muscles and/or joints and dizziness. Found causes in patients with vitamin B12 deficiency were: vegetarian diet, unbalanced diet, pernicious anaemia, the use of proton pump inhibitors and Imerslund Grasbeck syndrome. In 70% of the patients, no cause was found. Haematological changes were only found in a small percentage of patients. The best predictor of vitamin B12 deficiency was HoloTC, followed by tHcy, vitamin B12 and MMA. Furthermore we found that vitamin B12 was negatively correlated with MMA and tHcy and positively correlated with HoloTC. The sensitivity of vitamin B12 (cut off value: 200 pmol/l) was 82.2% and the specificity was 67.9%. The sensitivity of MMA (cut off value 280 nmol/l) was 79.1% and the specificity was 71.4%. The sensitivity of tHcy (cut off value 10 μmol/l) was 82.1% and the specificity was 71.4%. The sensitivity of HoloTC (cut off value 38 pmol/l) was 79.3% and the specificity was 72.7%. Conclusion Vitamin B12 deficiency in children may at presentation lack classical haematological and neurological symptoms and presents in less severe cases with many different non-specific symptoms. In addition, the cause of the vitamin B12 deficiency in children is frequently not found. Correlation between vitamin B12, the biomarkers and HoloTC have been well established. All the parameters seem to be good tests to establish vitamin B12 deficiency, with HoloTC being the best test. Estimated sensitivities & specificities of the parameters vary from 70 to 80% in children with suspected vitamin B12 deficiency. Since there is no test with a perfect discrimination between disease and no disease, we recommend using the clinical picture of the patient and all the parameters; vitamin B12, MMA, tHcy and HoloTC for the diagnosis of vitamin B12 deficiency in children. In the end, a positive treatment response corroborates the diagnosis.

Item Type:	Thesis (Thesis)
Supervisor name:	Tamminga, Dr. R.Y.J.
Faculty:	Medical Sciences
Date Deposited:	25 Jun 2020 10:59
Last Modified:	25 Jun 2020 10:59
URI:	https://umcg.studenttheses.ub.rug.nl/id/eprint/1934

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