Presumed retinal lead poisoning: a case report.

PURPOSE: To describe a case of presumed retinal lead poisoning. METHODS: Clinical examination, optical coherence tomography, fundus autofluorescence, fluorescein angiography, and electroretinography were used to study a 42-year-old male with the complaint of bilateral reduced vision following systemic lead poisoning. RESULTS: The fundus examination showed venous tortuosity, as well as macular atrophy, and pigmentary changes in his both eyes. Optical coherence tomography revealed retinal thinning, outer retinal and retinal pigment epithelium atrophy, as well as foveal schitic changes. Blue autofluorescence showed moderately hypoautofluorescence in peripapillary area of both eyes. Fluorescein angiogram showed a leopard-like pattern of hypo- and hyperfluorescence in the posterior pole. Electroretinogram showed a moderate reduction in photopic and scotopic responses. CONCLUSIONS: The most probable diagnosis of this case is early onset retinal lead poisoning.

Biomimetic Antidote Nanoparticles: a Novel Strategy for Chronic Heavy Metal Poisoning.

Chronic lead poisoning has become a major factor in global public health. Chelation therapy is usually used to manage lead poisoning. Dimercaptosuccinic acid (DMSA) is a widely used heavy metal chelation agent. However, DMSA has the characteristics of poor water solubility, low oral bioavailability, and short half-life, which limit its clinical application. Herein, a long-cycle slow-release nanodrug delivery system was constructed. We successfully coated the red blood cell membrane (RBCM) onto the surface of dimercaptosuccinic acid polylactic acid glycolic acid copolymer (PLGA) nanoparticles (RBCM-DMSA-NPs), which have a long cycle and detoxification capabilities. The NPs were characterized and observed by particle size meters and transmission electron microscopy. The results showed that the particle size of RBCM-DMSA-NPs was approximately 146.66 ± 2.41 nm, and the zeta potential was - 15.34 ± 1.60 mV. The homogeneous spherical shape and clear core-shell structure of the bionic nanoparticles were observed by transmission electron microscopy. In the animal tests, the area under the administration time curve of RBCM-DMSA-NPs was 156.52 ± 2.63 (mg/L·h), which was 5.21-fold and 2.36-fold that of free DMSA and DMSA-NPs, respectively. Furthermore, the median survival of the RBCM-DMSA-NP treatment group (47 days) was 3.61-fold, 1.32-fold, and 1.16-fold for the lead poisoning group, free DMSA, and DMSA-NP groups, respectively. The RBCM-DMSA-NP treatment significantly extended the cycle time of the drug in the body and improved the survival rate of mice with chronic lead poisoning. Histological analyses showed that RBCM-DMSA-NPs did not cause significant systemic toxicity. These results indicated that RBCM-DMSA-NPs could be a potential candidate for long-term chronic lead exposure treatment.

Chronic lead poisoning induced abdominal pain and anemia: a case report and review of the literature.

BACKGROUND: Chronic lead poisoning (CLP) is a rare cause of abdominal pain and is common in young children, in whom the incidence is higher than it is in adults. As the symptoms of CLP are nonspecific, misdiagnoses or missed diagnoses often occur, especially in sporadic cases. CASE PRESENTATION: We report a 28-year-old young man who was misdiagnosed with renal colic due to sudden acute abdominal pain. After a detailed medical history and physical examination, other possible causes were excluded, CLP was finally diagnosed, and he recovered after chelation treatment. CONCLUSION: Abdominal pain is a very common clinical symptom in adults, which has many causes. We should be vigilant against chronic poisoning, especially CLP. Detailed diagnosis and physical examination are crucial in early diagnosis and treatment.

Changes in inflammatory cytokines, antioxidants and liver stiffness after chelation therapy in individuals with chronic lead poisoning.

BACKGROUND: Chronic exposure to lead causes lead to accumulate mainly in the liver. In vivo studies have shown that lead toxicity is related to alterations in the inflammatory response. We aimed to evaluate the association between lead poisoning and liver fibrosis as well as the change in the degree of liver fibrosis, levels of inflammatory mediators and glutathione (GSH) after chelation therapy. METHODS: Workers from a battery factory who were exposed to lead for > 12 months and had a blood lead level (BLL) > 70 µg/dL were enrolled (n = 86) in the study. Participants underwent chelation therapy with intravenous CaNa2EDTA for 2 days followed by treatment with oral D-penicillamine for 90 days. The primary outcome was the change in the degree of liver fibrosis, which was presented as liver stiffness (LS) measured by FibroScan®. Secondary outcomes were the changes in the levels of serum GSH and inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) after chelation therapy. RESULTS: Among the 86 participants, there was a positive correlation between the duration of lead exposure and LS (r = 0.249, p = 0.021). To avoid the confounding effect of obesity-related steatosis, only 70 individuals who had controlled attenuation parameters < 296 dB/m, BMI < 25 kg/m2 and normal waist circumference were included in the interventional analysis. After chelation, the mean LS significantly decreased from 5.4 ± 0.9 to 4.8 ± 1.4 kPa (p = 0.001). Similarly, all of the inflammatory cytokines studied significantly decreased after chelation (p < 0.001); TNF-α decreased from 371.6 ± 211.3 to 215.8 ± 142.7; the levels of IL-1ß decreased from 29.8 ± 1.7 to 25.9 ± 4.3; and the levels of IL-6 decreased from 46.8 ± 10.2 to 35.0 ± 11.9. On the other hand, the mean GSH level increased significantly from 3.3 ± 3.3 to 13.1 ± 3.7 (p < 0.001) after chelation therapy. CONCLUSION: The duration of lead exposure was significantly correlated with the degree of liver fibrosis. Chelation treatment was associated with increased levels of GSH and decreased levels of proinflammatory cytokines and could potentially reduce the degree of LS. TRIAL REGISTRATION: This study was retrospectively registered and approved by the Thai Clinical Trial Registry (TCTR) on 2019-11-07. The TCTR identification number is TCTR20191108001 .

Lead encephalopathy in adults.

Lead poisoning is a common occupational health hazard in developing countries. We report the varied clinical presentation, diagnostic and management issues in two adult patients with lead encephalopathy. Both patients worked in a battery manufacturing unit. Both patients presented with seizures and one patient also complained of abdominal colic and vomiting. Both were anemic and a lead line was present. Blood lead level in both the patients was greater than 25 µg/dl. Magnetic resonance imaging of brain revealed bilateral symmetric involvement of the thalamus, lentiform nucleus in both patients and also the external capsules, sub-cortical white matter in one patient. All these changes, seen as hyperintensities in T2-weighted images suggested demyelination. They were advised avoidance of further exposure to lead and were treated with anti-epileptics; one patient also received D-penicillamine. They improved well on follow-up. Lead encephalopathy is an uncommon but important manifestation of lead toxicity in adults.