Toxic nephropathy secondary to chronic mercury poisoning: clinical characteristics and outcomes

A Patient With Proteinuria, Myalgias, and Decreased Pigmentation of Facial Skin

A patient had bilateral leg edema, insomnia, myalgias, paresthesias in the fingertips, lighter pigmentation of the facial skin compared with other areas of the body, proteinuria, and an elevated creatinine level. What is the diagnosis and what would you do next?

Chronic kidney disease and the global public health agenda: an international consensus

Early detection is a key strategy to prevent kidney disease, its progression and related complications, but numerous studies show that awareness of kidney disease at the population level is low. Therefore, increasing knowledge and implementing sustainable solutions for early detection of kidney disease are public health priorities. Economic and epidemiological data underscore why kidney disease should be placed on the global public health agenda - kidney disease prevalence is increasing globally and it is now the seventh leading risk factor for mortality worldwide. Moreover, demographic trends, the obesity epidemic and the sequelae of climate change are all likely to increase kidney disease prevalence further, with serious implications for survival, quality of life and health care spending worldwide. Importantly, the burden of kidney disease is highest among historically disadvantaged populations that often have limited access to optimal kidney disease therapies, which greatly contributes to current socioeconomic disparities in health outcomes. This joint statement from the International Society of Nephrology, European Renal Association and American Society of Nephrology, supported by three other regional nephrology societies, advocates for the inclusion of kidney disease in the current WHO statement on major non-communicable disease drivers of premature mortality.

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

Heavy metal poisoning caused by Chinese folk remedies in psoriasis patients: a retrospective analysis

Psoriasis, characterized as a chronic relapsing disease with a protracted course, often drives patients to seek relief through Chinese folk remedies (CFR). Nonetheless, the complex compositions of these remedies frequently result in unintended adverse effects, notably various types of heavy metal poisoning. Our study involved an exhaustive collection and analysis of clinical data from psoriasis patients who developed heavy metal poisoning due to CFR usage, admitted to Beijing Chao-Yang Hospital from January 2011 to October 2023. Our analysis identified 44 cases of mercury poisoning, 17 of lead poisoning, 21 of arsenic poisoning, and 4 instances of mixed heavy metal poisoning. The folk remedies used ranged from fumigation and inhalation to skin application and oral administration. Distinct pathogenic characteristics were observed in each poisoning type. After treatment with metal chelating agents, all patients experienced a reduction in heavy metal levels in their bodies, accompanied by varying degrees of symptom alleviation. This study underscores the vital necessity of opting for formal, medically approved treatments for psoriasis, thereby avoiding the hazardous consequences of unregulated folk remedies that may lead to severe heavy metal poisoning.

Association of Combined Per- and Polyfluoroalkyl Substances and Metals with Chronic Kidney Disease

Background: Exposure to environmental pollutants such as metals and Per- and Polyfluoroalkyl Substances (PFAS) has become common and increasingly associated with a decrease in the estimated Glomerular Filtration Rate (eGFR), which is a marker often used to measure chronic kidney disease (CKD). However, there are limited studies involving the use of both eGFR and the urine albumin creatinine ratio (uACR), which are more comprehensive markers to determine the presence of CKD and the complexity of pollutant exposures and response interactions, especially for combined metals and PFAS, which has not been comprehensively elucidated. Objective: This study aims to assess the individual and combined effects of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), Cadmium (Cd), Mercury (Hg), and Lead (Pb) exposure on CKD using data from the National Health and Nutritional Examination Survey (NHANES) 2017-2018. Methods: We employed the use of bivariate logistic regression and Bayesian Kernel Machine Regression (BKMR) in our analysis of the data. Results: Logistic regression results revealed a positive association between PFOA and CKD. Our BKMR analysis revealed a non-linear and bi-phasic relationship between the metal exposures and CKD. In our univariate exposure-response function plot, Cd and Hg exhibited a U and N-shaped interaction, which indicated a non-linear and non-additive relationship with both low and high exposures associated with CKD. In addition, the bivariate exposure-response function between two exposures in a mixture revealed that Cd had a U-shaped relationship with CKD at different quantiles of Pb, Hg, PFOA, and PFOS, indicating that both low and high levels of Cd is associated with CKD, implying a non-linear and complex biological interaction. Hg's interaction plot demonstrated a N-shaped association across all quantiles of Cd, with the 75th quantile of Pb and the 50th and 75th quantiles of PFOA and PFOS. Furthermore, the PIP results underscored Cd's consistent association with CKD (PIP = 1.000) followed by Hg's (PIP = 0.9984), then PFOA and PFOS with a closely related PIP of 0.7880 and 0.7604, respectively, and finally Pb (PIP = 0.6940), contributing the least among the five environmental pollutants on CKD, though significant. Conclusions: Our findings revealed that exposure to environmental pollutants, particularly Hg and Cd, are associated with CKD. These findings highlight the need for public health interventions and strategies to mitigate the cumulative effect of PFAS and metal exposure and elucidate the significance of utilizing advanced statistical methods and tools to understand the impact of environmental pollutants on human health. Further research is needed to understand the mechanistic pathways of PFAS and metal-induced kidney injury and CKD, and longitudinal studies are required to ascertain the long-term impact of these environmental exposures.

An Updated Review of Membranous Nephropathy

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults. The discovery of phospholipase A2 receptor (PLA2R) as a target antigen has led to a paradigm shift in the understanding and management of MN. At present, serum PLA2R antibodies are used for diagnosis, prognostication, and guiding treatment. Now, with the discovery of more than 20 novel target antigens, antigen mapping is almost complete. The clinical association of certain antigens provides clues for clinicians, such as the association of nerve epidermal growth factor-like 1 with malignancies and indigenous medicines. Serum antibodies are detected for most target antigens, except exostosin 1 and 2 and transforming growth factor-beta receptor 3, but their clinical utility is yet to be defined. Genome-wide association studies and studies investigating environmental factors, such as air pollution, shed more light on the underpinnings of MN. The standard therapy of MN diversified from cyclical cyclophosphamide and steroids to include rituximab and calcineurin inhibitors over the past decades. Here, we provide a cutting-edge review of MN, focusing on genetics, immune system and environmental factors, novel target antigens and their clinical characteristics, and currently available and emerging novel therapies in MN.

Clinicopathological features and long-term prognosis of glomerular diseases associated with mercury-containing cosmetics

OBJECTIVE

The pathological types and long-term prognosis of glomerular diseases related to mercury exposure are unclear. This study retrospectively examined 41 cases of glomerulonephropathy caused by mercury-containing cosmetics.

METHODOLOGY

Forty-one subjects with glomerular diseases presumably caused by mercury-containing cosmetics were selected. Clinical features, kidney biopsy, treatment, and follow-up data were collected.

RESULTS

All patients were female with an average age of 39.4 ± 6.6 years at diagnosis. Median time of exposure to mercury-containing cosmetics was six months, and average urine mercury level was 66.80 ± 38.55ug/(g·Cr). Most patients presented with nephrotic syndrome. Renal histopathology showed membranous nephropathy in 22 patients (53.65%), minimal change disease in 13 patients (31.71%), IgA nephropathy with minimal change disease in 5 patients (12.20%), and focal segmental glomerulosclerosis in 1 patient. Median time of exposure to mercury was longer and the proportion of patients with autoantibodies (mainly antinuclear antibodies) was higher in patients with membranous nephropathy. Both blood phospholipase A2 receptor -Ab and kidney tissue phospholipase A2 receptor were negative. Thirty-six patients received glucocorticosteroids and/or immunosuppressants. Five patients were treated with an angiotensin receptor blocker, and nine patients were treated with chelation therapy. The median follow-up time was 40 months (range 27-94). All patients achieved complete remission, and the median time to complete remission was one month. They all successfully discontinued the drugs without relapsing; withdrawal time was 26 months.

CONCLUSION

Membranous nephropathy was the most common pathological type in mercury-induced glomerular disease. Patients were sensitive to glucocorticosteroids and immunosuppressants and achieved complete remission quickly. Contrary to primary glomerulonephritides, patients with mercury-induced glomerular diseases had no relapses after withdrawal of the mercury containing cosmetics.

The expanding spectrum and utility of antigens in membranous nephropathy

PURPOSE OF REVIEW

Multiple antigenic targets were discovered in membranous nephropathy, representing distinct autoimmune diseases with a similar morphologic pattern of injury. An overview of recent developments, including antigen types, clinical associations, serologic monitoring, and advancements in understanding disease pathogenesis are provided.

RECENT FINDINGS

Several new antigenic targets have defined subtypes of membranous nephropathy, including Neural epidermal growth factor-like 1, protocadherin 7, HTRA1, FAT1, SEMA3B, NTNG1, NCAM1, exostosin 1/2, transforming growth factor beta receptor 3, CNTN1, proprotein convertase subtilisin/kexin type 6, and neuron-derived neurotrophic factor. Autoantigens in membranous nephropathy may demonstrate unique clinical associations, assisting the nephrologist to identify potential disease etiologies and triggers, such as autoimmune disease, cancer, medications, and infections.

SUMMARY

We are entering an exciting era for which an antigen-based approach will further define subtypes of membranous nephropathy, allow for development of noninvasive diagnostics, and improve care for patients.

Mercury-associated neural epidermal growth factor-like 1 protein (NELL-1) positive membranous nephropathy after use of skin lightening creams

INTRODUCTION

Membranous nephropathy, one of the common causes of glomerulonephritis worldwide, is reported in association with mercury exposure. Neural epidermal growth factor-like 1 protein is a recently described target antigen in membranous nephropathy.

CASE SERIES

Three woman (ages 17, 39, and 19 years old) presented sequentially for our evaluation with complaints consistent with nephrotic syndrome. All three had nephrotic range proteinuria, hypoalbuminemia, hypercholesterolemia, hypothyroidism, and inactive urinary sediments. Kidney biopsies were performed in the first two patients, which demonstrated findings consistent with membranous nephropathy and positive staining for neural epidermal growth factor-like 1 protein. On discovery that they were all using the same skin-lightening cream, samples of the cream were tested and found to contain between 2,180 parts per million and 7,698 parts per million of mercury. Elevated urine and blood mercury concentrations were also found in the first two patients. All three patients improved following cessation of use and treatment with levothyroxine (all three patients) and corticosteroids and cyclophosphamide in patients one and two.

DISCUSSION

We hypothesize the role of autoimmunity triggered by mercury exposure in the pathogenesis of neural epidermal growth factor-like 1 protein membranous nephropathy.

CONCLUSION

Mercury exposure should be carefully assessed as a part of the evaluation of patients with neural epidermal growth factor-like 1 protein positive membranous nephropathy.

Lactic acid bacteria strains reduce in vitro mercury toxicity on the intestinal mucosa

A bicameral model consisting of Caco-2 and HT29-MTX intestinal epithelial cells and THP-1-derived macrophages has been used to test the ability of two strains of Lactobacillus to protect from damage caused by mercury. Exposure to 1 mg/ml mercury [Hg(II) or methyl-Hg] for seven days in this model resulted in an inflammatory and pro-oxidant response mainly driven by macrophages. This led to an impairment in the intestinal barrier, defective tight-junctions, increased permeability and mucus hypersecretion. In addition, the wound-healing capacity of the epithelial monolayer was also diminished. However, the presence of heat-killed Lactobacillus intestinalis or Lactobacillus johnsonii cells during Hg exposure reverted these effects, and most of the parameters recovered values similar to control cells. Both lactobacilli showed the capacity to bind Hg(II) and methyl-Hg under the cell culture conditions. This points to Hg sequestration as a likely mechanism that counteracted Hg toxicity. However, differences in the Hg binding capacity and in the effects between both strains suggest that other probiotic-mediated mechanisms may play a role in the alleviation of the damage elicited by Hg. These results show the potential of the bicameral intestinal epithelial model for screening of effective strains for their use in later in vivo studies.

Molecular Mechanisms of Cellular Injury and Role of Toxic Heavy Metals in Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive disease that affects millions of adults every year. Major risk factors include diabetes, hypertension, and obesity, which affect millions of adults worldwide. CKD is characterized by cellular injury followed by permanent loss of functional nephrons. As injured cells die and nephrons become sclerotic, remaining healthy nephrons attempt to compensate by undergoing various structural, molecular, and functional changes. While these changes are designed to maintain appropriate renal function, they may lead to additional cellular injury and progression of disease. As CKD progresses and filtration decreases, the ability to eliminate metabolic wastes and environmental toxicants declines. The inability to eliminate environmental toxicants such as arsenic, cadmium, and mercury may contribute to cellular injury and enhance the progression of CKD. The present review describes major molecular alterations that contribute to the pathogenesis of CKD and the effects of arsenic, cadmium, and mercury on the progression of CKD.

Risk assessment and early warning of the presence of heavy metal pollution in strawberries

Heavy metal pollution is a major threat to agricultural produce and it can pose potential ecological risks which subsequently impacts on human health. Strawberries are an economically important produce of China. The intrinsic link of heavy metal pollution risk in the soil-strawberry ecosystem is of concern. In this study, the pollution index of heavy metal pollutants in farmlands of different provinces were evaluated, and the results showed significantly high levels of cadmium. In addition, Nemerow integrated pollution index analysis showed that low-pollution farmlands only accounted for 14.07% of the total arable land area. Then, the transfer factors were used to calculate the migration of heavy metals from the soil into strawberries. The results showed that cadmium and nickel were relatively high in strawberries from the Guangxi province. Similar results were found for mercury in Jiangxi Province. The pollution index of single food pollution also showed that mercury in strawberries from Jiangxi Province was at a moderate pollution level. The comprehensive pollution index indicated that heavy metal pollution in strawberries in Central China may be severe. In addition, spatial clustering analysis showed that cadmium, chromium, lead, arsenic and zinc in strawberries had significant hotspot clustering in central, south and southwest China. Finally, our studies also suggested that the risk of carcinogenic and non-carcinogenic diseases was higher in the (2, 4] years age group than in other age groups. People in Yunnan Province were also found to have a higher non-carcinogenic risk than those in other provinces and cities in China. This study provides a comprehensive view of the potential risks of heavy metal contamination in strawberries, which could provide assistance in the design of regulatory and risk management programs for chemical pollutants in strawberries, thus ensuring the safety of consumption of these edible fruits.