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• Thiamine compounds in humans
  Marco Poloni
  Published on: 13 April 2016

• Published on: 13 April 2016

  Thiamine compounds in humans

  • Marco Poloni, researcher

  I have some comments concerning the report by S. Jesse, D.R. Thal and A.C. Ludolph, recently published in JNNP September 15 2015, pag. 1166-1168 "Thiamine deficiency in Amyotrophic Lateral Sclerosis". In a research dated 1981 Rindi et al. showed that in 12 CSF samples obtained from different healthy subjects, without any clinical disorder involving thiamin status, the only thiamin compounds detected after electrophoretic...

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  I have some comments concerning the report by S. Jesse, D.R. Thal and A.C. Ludolph, recently published in JNNP September 15 2015, pag. 1166-1168 "Thiamine deficiency in Amyotrophic Lateral Sclerosis". In a research dated 1981 Rindi et al. showed that in 12 CSF samples obtained from different healthy subjects, without any clinical disorder involving thiamin status, the only thiamin compounds detected after electrophoretic separation were constantly free thiamine (T) and thiamine- monophosphate (TMP), their mean percentage being 40.7% and 59.3% of total thiamin content respectively. EXPERIENTIA 37, 975-976 (1981). In a successive study Poloni et al. (Arch. Neurol., 1982,39, 507-509) measured free thiamin and thiamin monophosphate levels in plasma and cerebral spinal fluid of patients with ALS, alcoholics, and controls. In plasma of patients with ALS, as well as in plasma and cerebrospinal fluid (CSF) of alcoholics, both thiamin and thiamin monophosphate concentrations were decreased. In CSF of patients with ALS, however, thiamin monophosphate values decreased much more than thiamin levels. This same finding has been observed, interestingly, only in pigs who showed together with rabbits, the highest levels of thiamine in the CSF. In our opinion the selective impairment of thiamin monophosphate production by nerve cells is likely to result from the reduction of the activity of thiamin pyrophosphatase, an enzyme synthesized and highly concentrated in the Golgi complex, a component of the cell where complex molecules such as proteins are synthesized and packaged for use in the body. Thiamin pyrophosphatase diminish in ALS, as well as in experimental motor neuronal degeneration or axotomy. Thus, the thiamin to thiamin monophosphate ratio could be taken as an index of the impairment of neuronal protein synthesis in ALS (Poloni et al.., Arch. Neurol., 1982, 39, 507-509). In an other study, thiamine and thiamine monophosphate levels were measured in the CSF of patients with typical sporadic ALS (50 cases), in other motor neuron diseases (MND) (14 cases), and in patients with upper and/or lower motor neuron lesions of varying origin (disseminated sclerosis, polyneuropathy, spondylotic myelopathy). The thiamine to thiamine monophosphate ratio was greater than or equal to 1 in a high percentage of patients with typical sporadic ALS (94%), in 35.7% of cases with other MND, while it was below one in all the other patients. The decrease of thiamin monophosphate with the inversion of the thiamin to thiamin monophosphate ratio is a finding highly specific to typical sporadic ALS (Poloni et al. It.J.Neurol: Sci.,1986). Other researchers measured the enzymes involved in thiamin synthesis: thiamin pyrophosphatase (TPPase) and thiamin monophosphatase (TMPase) in brain tissue obtained at autopsy from ALS and Parkinsonism-dementia patients from Guam and from Guamanian patients who died from other diseases (controls). TPPase content, chemically determined at pH 9.0, was found to be significantly reduced in the frontal cortex of ALS and Parkinsonism-dementia patients compared to controls. TMPase content, on the contrary, was unchanged (Laforenza et al., J. Neurol. Sci., 1992). Thiamin deficiency causes dry beriberi, a neurologic al disease characterized by "burning" feet, peripheral neuropathy, and Wernicke- Korsakoff syndrome; on this background, in my opinion the method used in this paper to determinate the level of thiamine is indirect and easily subject to drawbacks; Wernicke encephalopathy, istologically observed in two ALS cases, may be due to undernutrition that may be frequently associated in a disease where severe dysphagia may be present in the terminal stage. The reason of the low TMP CSF levels with inversion of the ratio T/TMP, peculiar of ALS patients and ineterestingly found only in pigs, remains unexplained.

  Conflict of Interest:

  None declared

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  Conflict of Interest:
  None declared.

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