Misdiagnosis and long-term outcome of 13 patients with acute thallium poisoning in China

Thallium-induced DNA damage, genetic, and epigenetic alterations

Thallium (Tl) is a toxic heavy metal responsible for noxious effects in living organisms. As a pollutant, Tl can be found in the environment at high concentrations, especially in industrial areas. Systemic toxicity induced by this toxic metal can affect cell metabolism, including redox alterations, mitochondrial dysfunction, and activation of apoptotic signaling pathways. Recent focus on Tl toxicity has been devoted to the characterization of its effects at the nuclear level, with emphasis on DNA, which, in turn, may be responsible for cytogenetic damage, mutations, and epigenetic changes. In this work, we review and discuss past and recent evidence on the toxic effects of Tl at the systemic level and its effects on DNA. We also address Tl's role in cancer and its control.

Early diagnosis, treatment, and outcomes of five patients with acute thallium poisoning

BACKGROUND

Thallium poisoning is rare and difficult to recognize. Early diagnosis and treatment of thallium-poisoned patients are essential to prevent morbidity and mortality.

AIM

To evaluate the efficacy of treatments and outcomes of five patients with early diagnosis of acute thallium poisoning.

METHODS

Five patients who consumed a thallium-contaminated meal were hospitalized in succession, and underwent clinical examinations such as blood tests and electromyography tests. Urine and blood tests confirmed the diagnosis of thallotoxicosis, revealing the occurrence of food poisoning. All patients underwent detoxification treatment, including hemoperfusion (HP) and treatment with Prussian blue (PB). A 24-mo follow-up was performed to evaluate the long-term outcomes on the patients after discharge.

RESULTS

Initially, the patients presented with symptoms of acute thallium poisoning including hyperalgesia of the limbs and abdominalgia, which may differ from common peripheral neuropathy. Accompanying symptoms such as hepatic damage and alopecia were observed in all the patients, which further confirmed the diagnosis of poisoning. Treatment with chelating agents was ineffective, while HP and treatment with PB drastically decreased the thallium concentration in the urine and blood. With early diagnosis and intervention, four patients had a good prognosis and no permanent sequelae. One patient developed blindness and disability during the 24-mo follow-up period.

CONCLUSION

Identification of incident cluster and characteristic symptoms is extremely important for early diagnosis of acute thallium poisoning. HP plus PB is essential to improve the prognosis of thallium-poisoned patients.

Dual dye-labeled G-quadruplex aptasensor for detection of thallium(I) using ratiometric fluorescence resonance energy transfer

A fluorescent probe was developed for ratiometric detection of thallium ions in mineral water samples by modifying a G-rich aptamer (PS2.M - 7) with a fluorescence donor (Cyanine-3, Cy₃) and a quencher (Cyanine-5, Cy₅). The probe had a random coil structure that changed into a G-quadruplex structure upon binding with Tl⁺. This change in structure decreased the distance between the donor and acceptor moieties, which resulted in fluorescence resonance energy transfer between Cy₃ and Cy₅. Under optimized conditions, the limit of detection and linear concentration range for Tl⁺ were 30.1 μM (3σ) and 10 μM-10 mM (R² = 0.9981), respectively. This simple and cost-effective fluorescence sensor provided satisfactory results for detection of thallium ions in spiked mineral water samples.

Long-term misdiagnosis and neurologic outcomes of thallium poisoning: A case report and literature review

INTRODUCTION

Thallium poisoning is a rare occurrence. Therefore, thallium poisoning is easily misdiagnosed and is often accompanied by a series of serious sequelae and can even result in death in severe cases. Here, we report long-term follow-up of a case of a patient who was poisoned with thallium on two separate occasions.

METHODS

A 43-year-old man was initially misdiagnosed as gastroenteritis, diabetic peripheral neuropathy, and Guillain-Barré Syndrome (GBS) within 21 months. The correct diagnosis was confirmed by blood and urine thallium assays. After Prussian blue treatment, thallium was undetectable in the blood by day 60. Following this investigation, a criminal suspect confessed to two instances of adulterating thallium sulfate in the patient's beverage. A 6-year follow-up was performed after discharge, and a comprehensive literature was review.

RESULTS

We found that the original gastrointestinal symptoms, skin lesions, and hair loss were reversed and had recovered, except for residual neurologic damage, even with long-term rehabilitation.

DISCUSSION

Thallium intoxication may have been initially identified if neurologic symptoms had occurred concurrently with gastrointestinal and cutaneous symptoms. Neurologic damage represented the main sequelae of thallium poisoning in our present case report.

Prenatal serum thallium exposure and 36-month-old children's attention-deficit/hyperactivity disorder symptoms: Ma'anshan birth cohort study

Thallium (Tl) is a highly toxic heavy metal that has been suggested to be responsible for oxidative stress and mitochondrial dysfunction. However, few studies have focused on the relationship of prenatal Tl exposure with children's neurobehavioural development. The purpose of our study was to investigate the association between prenatal Tl exposure and attention-deficit/hyperactivity disorder (ADHD) symptoms in 36-month-old children. We used data from 2851 mother-newborn pairs from the Ma'anshan Birth Cohort Study (MABC); serum Tl concentration was assessed in the first, second and third trimesters of pregnancy as well as in the umbilical cord blood. We assessed ADHD symptoms in the children using the Chinese version of the Conners abbreviated symptom questionnaire (C-ASQ). The adjusted odds ratio (OR) for the risk of ADHD symptoms was 2.00 [95% confidence interval (CI): 1.20, 3.32] and 2.08 (95% CI: 1.26, 3.43) for the third (60.25-75.21 ng/L) and fourth quartiles of serum Tl (>75.21 ng/L), respectively, in the second trimester of pregnancy, in comparison with the first quartile of serum Tl (<50.86 ng/L). The risk of ADHD symptoms was elevated among boys exposed to the fourth quartile of serum Tl in the second trimester of pregnancy (adjusted OR 2.08, 95% CI: 1.13, 3.83). Our results demonstrated that high levels of Tl exposure in the second trimester of pregnancy were related to a higher risk of ADHD symptoms in 36-month-old children, and the association of higher serum Tl exposure in the second trimester with ADHD symptoms was only found in boys.

Clinical characteristics and treatment of thallium poisoning in patients with delayed admission in China

Thallium is highly toxic and its effects are cumulative. The clinical symptoms of thallium poisoning are non-specific, thereby delaying admission and treatment. This study aimed to summarize the clinical features and treatment experience of patients with delayed admission who experience thallium poisoning.We conducted a retrospective descriptive analysis of patients in our hospital from 2008 to 2018 who had thallium poisoning and experienced a delay in hospital admission. The time from symptom onset to admission was assessed. The patients were divided into 3 groups and descriptive analyses of their clinical characteristics, including basic patient information, symptoms, laboratory test results, examination findings, treatment methods, outcomes, and follow-up information, were conducted.A total of 34 patients with thallium poisoning were included: 8 were admitted to the hospital early or with mild delay, 9 had a moderate delay, and 17 had a severely delayed admission. The time from illness onset to admission was 13 (interquartile range, 7.5-26) days. Some patients with delayed admission had significant symptoms associated with central nervous system damage, and changes in magnetic resonance images and electroencephalograms were also noted. After admission, all patients received Prussian blue treatment, and some patients with relatively high blood concentration received blood purification treatments. Following treatment, the blood and urine thallium concentrations of all patients decreased significantly, and their symptoms were alleviated.Our results show that delayed patient admission in cases of thallium poisoning is associated with greater risk of central nervous system damage. Use of Prussian blue combined with blood purification treatments might improve patients' conditions.

Successful treatment of a patient with severe thallium poisoning in a coma using Prussian blue and plasma exchange: A case report

RATIONALE

This is the first reported severe thallium poisoning patient successfully treated with Prussian blue (PB) and plasma exchange (PE).

PATIENT CONCERNS

A 42-year-old woman in a coma owing to severe thallium poisoning was admitted to our department after day 44 of poisoning. At admission, blood and urine thallium concentrations were 380.0 and 2580.0 ng/mL, respectively.

DIAGNOSIS

The patient was diagnosed with toxic encephalopathy induced by thallium poisoning; in addition, she was also diagnosed with bilateral pneumonia, respiratory failure, moderate anemia, hypoproteinemia, and electrolyte imbalance based on her chest X-ray, blood gas analysis, Hb level, albumin levels, and serum electrolyte results.

INTERVENTIONS

The patient was intubated and treated with PB (6600 mg/d, 15 days in total) combined with PE (once daily, 5 days in total) as well as other symptomatic supportive care measures.

OUTCOMES

After treatments, her blood and urinary thallium concentrations gradually decreased and on the 13th day after admission, the blood thallium concentration decreased to 0 ng/mL. The oxygenation index gradually improved, meantime, the patient gradually regained consciousness, and on the 50th day of admission, the patient's consciousness reverted to a clear-headed state. The patient recovered mostly after 37 months of follow-up.

LESSONS

Through this case, we learned that the gradual reduction in blood and urine thallium concentration and the patient's improved condition is correlated with PB and PE treatment. For patients with severe thallium poisoning, this treatment method might be effective; but the exact curative effect is unconfirmed, requiring further research to verify.

Hair Loss: Evidence to Thallium Poisoning

In clinical practice, thallium poisoning is very hard to diagnose, because it is a very uncommon disease and its clinical manifestations are extremely complicated. In the present study, we investigated a case of a 53-year-old man who was hospitalized for persistent stabbing pain in the abdomen and lower extremities for 20 days. Physical examination revealed diffuse alopecia of the scalp. The final diagnosis of thallium poisoning was confirmed based on high blood and urine thallium levels. The patient was cured by an oral administration of Prussian blue combined with hemoperfusion and continuous veno-venous hemofiltration.

Metals and Neurodegeneration

Metals play important roles in the human body, maintaining cell structure and regulating gene expression, neurotransmission, and antioxidant response, to name a few. However, excessive metal accumulation in the nervous system may be toxic, inducing oxidative stress, disrupting mitochondrial function, and impairing the activity of numerous enzymes. Damage caused by metal accumulation may result in permanent injuries, including severe neurological disorders. Epidemiological and clinical studies have shown a strong correlation between aberrant metal exposure and a number of neurological diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, autism spectrum disorders, Guillain–Barré disease, Gulf War syndrome, Huntington’s disease, multiple sclerosis, Parkinson’s disease, and Wilson’s disease. Here, we briefly survey the literature relating to the role of metals in neurodegeneration.

Thallium Transfer from Hydrochloric Acid Media into Pure Ionic Liquids

Pure hydrophobic ionic liquids are known to extract metallic species from aqueous solutions. In this work we have systematically investigated thallium (Tl) extraction from aqueous hydrochloric acid (HCl) solutions into six pure fluorinated ionic liquids, namely imidazolium- and pyrrolidinium-based ionic liquids with bis(trifluoromethanesulfonyl)imide and bis(fluorosulfonyl)-imide anions. The dependence of the Tl extraction efficiency on the structure and composition of the ionic liquid ions, metal oxidation state, and initial metal and aqueous acid concentrations have been studied. Tl concentrations were on the order of picomolar (analyzed using radioactive tracers) and millimolar (analyzed using inductively coupled plasma mass spectrometry). The extraction of the cationic thallium species Tl(+) is higher for ionic liquids with more hydrophilic cations, while for the TlX(z)(3-z) anionic species (where X = Cl(-) and/or Br(-)), the extraction efficiency is greater for ionic liquids with more hydrophobic cations. The highest distribution value of Tl(III) was approximately 2000. An improved mathematical model based on ion exchange and ion pair formation mechanisms has been developed to describe the coextraction of two different anionic species, and the relative contributions of each mechanism have been determined.