Public health response to methanol mass poisoning in the Czech Republic in 2012: a case study

Methanol Induced Optic Neuropathy: Molecular Mysteries, Public Health Perspective, Clinical Insights and Treatment Strategies

Methanol-induced optic neuropathy (MION) represents a critical public health issue, particularly prevalent in lower socioeconomic populations and regions with restricted alcohol access. MION, characterized by irreversible visual impairment, arises from the toxic metabolization of methanol into formaldehyde and formic acid, leading to mitochondrial oxidative phosphorylation inhibition, oxidative stress, and subsequent neurotoxicity. The pathogenesis involves axonal and glial cell degeneration within the optic nerve and potential retinal damage. Despite advancements in therapeutic interventions, a significant proportion of affected individuals endure persistent visual sequelae. The study comprehensively investigates the pathophysiology of MION, encompassing the absorption and metabolism of methanol, subsequent systemic effects, and ocular impacts. Histopathological changes, including alterations in retinal layers and proteins, Müller cell dysfunction, and visual symptoms, are meticulously examined to provide insights into the disease mechanism. Furthermore, preventive measures and public health perspectives are discussed to highlight the importance of awareness and intervention strategies. Therapeutic approaches, such as decontamination procedures, ethanol and fomepizole administration, hemodialysis, intravenous fluids, electrolyte balance management, nutritional therapy, corticosteroid therapy, and erythropoietin (EPO) treatment, are evaluated for their efficacy in managing MION. This comprehensive review underscores the need for increased awareness, improved diagnostic strategies, and more effective treatments to mitigate the impact of MION on global health.

Acute and chronic blood serum proteome changes in patients with methanol poisoning

Twenty-four blood serum samples from patients with acute methanol poisoning (M) from the mass methanol poisoning outbreak in the Czech Republic in 2012 were compared with 46 patient samples taken four years after poisoning (S) (overlap of 10 people with group M) and with a control group (C) of 24 samples of patients with a similar proportion of chronic alcohol abuse. When comparing any two groups, tens to hundreds of proteins with a significant change in concentration were identified. Fifteen proteins showed significant changes when compared between any two groups. The group with acute methanol poisoning showed significant changes in protein concentrations for at least 64 proteins compared to the other groups. Among the most important identified proteins closely related to intoxication are mainly those involved in blood coagulation, metabolism of vitamin A (increased retinol-binding protein), immune response (e.g., increased complement factor I, complement factors C3 and C5), and lipid transport (increased apolipoprotein A I, apolipoprotein A II, adiponectin). For blood coagulation, the most affected proteins with significant changes in the methanol poisoning group were von Willebrand factor, carboxypeptidase N, alpha-2-antiplasmin (all increased), inter-alpha-trypsin inhibitor heavy chain H4, kininogen-1, plasma serine protease inhibitor, plasminogen (all decreased). However, heparin administration used for the methanol poisoning group could have interfered with some of the changes in their concentrations. Data are available via ProteomeXchange with the identifier PXD035726.

Estimation of long-term costs of postacute care in survivors of the methanol poisoning outbreak

OBJECTIVES

To fill the existing research gap related to long-term costs of postacute care in methanol poisoning survivors, healthcare cost for 6 years after the outbreak has been modelled and estimated.

DESIGN

In a prospective longitudinal cohort study, data collected from 55 survivors of the Czech methanol mass poisoning outbreak in 2012 were collected in four rounds (5 months, then 2, 4 and 6 years after the discharge) in the General University Hospital in Prague according to the same predefined study protocol. The collected data were used to inform the cost model.

SETTING AND PARTICIPANTS

All 83 patients discharged from a hospital poisoning treatment after the 2012 methanol outbreak were informed about the study and invited to participate. Fifty-five patients (66%) gave their written informed consent and were followed until their death or the last follow-up 6 years later. The costs were modelled from the Czech healthcare service (general health insurance) perspective.

MAIN OUTCOME MEASURES

Long-term national budget impact of the methanol poisoning outbreak, frequencies of sequelae and their average costs.

RESULTS

The postacute cost analysis concentrated on visual and neurological sequelae that were shown to be dominant. Collected data were used to create process maps portraying gradual changes in long-term sequelae over time. Individual process maps were created for the central nervous system, peripheral nervous system, sequelae detected during eye examinations and sequelae concerning the visual evoked potentials. Based on the process maps the costs of the postacute outpatient care were estimated.

CONCLUSIONS

In 2013-2019 the highest costs per patient related to postacute care were found in the first year; the average costs decreased afterwards, and remained almost constant for the rest of the studied period of time. These costs per patient ranged from CZK4142 in 2013 to CZK1845 in 2018, when they raised to CZK2519 in 2019 again.

MRI-based brain volumetry and retinal optical coherence tomography as the biomarkers of outcome in acute methanol poisoning

BACKGROUND

Basal ganglia lesions are typical findings on magnetic resonance imaging (MRI) of the brain in survivors of acute methanol poisoning. However, no data are available on the association between the magnitude of damaged brain regions, serum concentrations of markers of acute methanol toxicity, oxidative stress, neuroinflammation, and the rate of retinal nerve ganglion cell loss.

OBJECTIVES

To investigate the association between MRI-based volumetry of the basal ganglia, retinal nerve fibre layer (RNFL) thickness and prognostic laboratory markers of outcomes in acute methanol poisoning.

METHODS

MRI-based volumetry of putamen, nucleus caudatus and globus pallidus was performed and compared with laboratory parameters of severity of poisoning and acute serum markers of oxidative damage of lipids (8-isoprostan, MDA, HHE, HNE), nucleic acids (8-OHdG, 8-OHG, 5-OHMU), proteins (o-Thyr, NO-Thyr, Cl-Thyr) and leukotrienes (LTC4, LTD4, LTE4, LTB4), as well as with the results of RNFL measurements by optic coherence tomography (OCT) in 16 patients with acute methanol poisoning (Group I) and in 28 survivors of poisoning two years after discharge with the same markers measured within the follow-up examination (Group II). The control group consisted of 28 healthy subjects without methanol poisoning.

RESULTS

The survivors of acute methanol poisoning had significantly lower volumes of basal ganglia than the controls. The patients with MRI signs of methanol-induced toxic brain damage had significantly lower volumes of basal ganglia than those without these signs. A positive correlation was found between the volume of putamen and arterial blood pH on admission (r = 0.45; p = 0.02 and r = 0.44; p = 0.02 for left and right putamen, correspondingly). A negative correlation was present between the volumes of putamen and acute serum lactate (r = -0.63; p < 0.001 and r = -0.59; p = 0.01), creatinine (r = -0.53; p = 0.01 and r = -0.47; p = 0.01) and glucose (r = -0.55; p < 0.001 and r = -0.50; p = 0.01) concentrations. The volume of basal ganglia positively correlated with acute concentrations of markers of lipoperoxidation (8-isoprostan: r = 0.61; p < 0.05 and r = 0.59; p < 0.05 for left and right putamen, correspondingly) and inflammation (leukotriene LTB4: r = 0.61; p < 0.05 and r = 0.61; p < 0.05 for left and right putamen, correspondingly). The higher the volume of the basal ganglia, the higher the thickness of the RNFL, with the strongest positive association between global RNFL and the volume of putamen bilaterally (all p < 0.01). In the follow-up markers of oxidative stress and inflammation, only o-Thyr concentration negatively correlated with the volume of putamen bilaterally (r = -0.39; p < 0.05 and r = -0.37; p < 0.05 for left and right putamen, correspondingly).

CONCLUSION

In survivors of acute methanol poisoning with signs of toxic brain damage, the magnitude of affected areas correlated with acute parameters of severity of poisoning, markers of oxidative stress and neuroinflammation. There was a positive association between the basal ganglia volume and the thickness of RNFL, making OCT an important screening test and MRI-based volumetry the confirmative diagnostic method for the detection of CNS sequelae of methanol poisoning.