Serum IgE elevation correlates with blood lead levels in battery manufacturing workers

Immune Responses to COVID-19 Vaccines in Patients with Chronic Kidney Disease and Lead Exposure

Literature data regarding the response rate to COVID-19 vaccination in chronic kidney disease (CKD) patients remain inconclusive. Furthermore, studies have reported a relationship between lead exposure and susceptibility to viral infections. This study examined immune responses to COVID-19 vaccines in patients with CKD and lead exposure. Between October and December 2021, 50 lead-exposed CKD patients received two doses of vaccination against COVID-19 at Chang Gung Memorial Hospital. Patients were stratified into two groups based on the median blood lead level (BLL): upper (≥1.30 μg/dL, n = 24) and lower (<1.30 μg/dL, n = 26) 50th percentile. The patients were aged 65.9 ± 11.8 years. CKD stages 1, 2, 3, 4 and 5 accounted for 26.0%, 20.0%, 22.0%, 8.0% and 24.0% of the patients, respectively. Patients in the lower 50th percentile of BLL had a lower proportion of CKD stage 5 than patients in the upper 50th percentile BLL group (p = 0.047). The patients in the lower 50th percentile BLL group also received a higher proportion of messenger RNA vaccines and a lower proportion of adenovirus-vectored vaccines than the patients in the upper 50th percentile BLL group (p = 0.031). Notably, the neutralizing antibody titers were higher in the lower 50th percentile than in the upper 50th percentile BLL group. Furthermore, the circulating levels of granulocyte-colony stimulating factor, interleukin-8, monocyte chemoattractant protein-1 and macrophage inflammatory protein-1α were higher in the upper 50th percentile than in the lower 50th percentile BLL group. Therefore, it was concluded that lead-exposed CKD patients are characterized by an impaired immune response to COVID-19 vaccination with diminished neutralizing antibodies and augmented inflammatory reactions.

Effects of long-term high-level lead exposure on the immune function of workers

This work was undertaken to study the immunomodulatory effects of long-term exposure to varying levels of lead (Pb) in workers. A total of 49 people who underwent occupational health examinations from 2009 to 2018 were selected as study subjects. Differences between the two group populations regarding the levels of T-lymphocytes, B-lymphocytes, natural killer (NK) cells, and granulocytes, as well as the levels of T_H1/T_H2/T_H17 cytokines, were evaluated. The results indicated that the percentages of CD3⁺ cells in the high-Pb group were significantly higher than those in the low-Pb counterparts (p < .05). In contrast, the percentages of CD3^-CD16⁺CD56⁺ cells were significantly lower in the high-Pb workers. There were no significant differences in other immunommy cells and T_H1/T_H2/T_H17 cytokine between the groups. CD3⁺ cell levels in workers positively correlated with blood Pb levels (Rs = 0.378, p = .007), while the expression of CD3^-CD16⁺CD56⁺ cells was negatively correlated (Rs = -0.320, p = .025). There was no significant correlation between blood Pb concentration and the other immune endpoints evaluated here.

Effects of Lead, Mercury, and Cadmium Co-exposure on Children's Pulmonary Function

Accumulating evidence has shown that toxic metals exposure can have adverse effects on children, but the effects of blood Pb, Hg, and Cd co-exposure on pulmonary function in children remains to be clarified. This cross-sectional multicenter study was conducted in Wuxi City, China. A total of 221 healthy children free from chronic obstructive pulmonary disease were recruited. The blood samples were collected while blood Pb, Hg, and Cd levels were determined. The forced vital capacity volume (FVC) and forced expiratory volume in the 1 s (FEV1) were measured. The associations between metals concentration and pulmonary function were analyzed by multiple linear regression models. The geometric means of the blood Pb, Hg, and Cd levels in our study were 37.27 μg/L, 1.41 μg/L, and 0.28 μg/L, respectively. After adjusting for age, sex, maternal education, annual family income, fish consumption, and second-hand smoking exposure, only the blood Pb levels were significantly negatively associated with the pulmonary function. In addition, a significantly positive interaction between blood Pb and blood Cd on pulmonary function were also detected. Although causal relationship cannot be confirmed in this study, at least higher levels of Pb in blood are associated with decreased pulmonary parameters in children.

Leukocyte apoptosis, TNF-α concentration and oxidative damage in lead-exposed workers

Lead intoxication can generate pro-inflammatory conditions that have been proposed to be associated with cell injuries and oxidative stress. The pro-inflammatory state can participate in the pathophysiology of this toxicity to generate immune response dysfunctions, which could condition the presence of clinical manifestations and susceptibility to infections already described in lead-exposed patients. In the present work, we study workers of a battery recycler factory (n = 24) who are chronically exposed to lead and compared them with non-lead exposed workers (n = 17). Lead-exposed workers had high lead concentrations in blood (med 69.8 vs. 1.7 μg/dL), low δ-ALAD activity (med 149 vs. 1100 nmol PBG/h/mL), high lipid peroxidation (med 0.86 vs. 0.69 nmol/mL) and high erythrocytes apoptosis (med 0.81 vs. 0.50% PS externalization) in relation to non-lead exposed workers. Also, lead-exposed workers had a high incidence of signs and symptoms related to lead intoxication and a higher frequency of infections. The higher leukocyte apoptosis (med 18.3 vs. 8.2% PS externalization) and lower basal TNF-α concentration (med 0.38 vs. 0.94 pg/mL) in lead-exposed workers imply an immune response dysfunction; however, there was no difference in the TNF-α concentration when leukocytes were stimulated with lipopolysaccharide in whole blood (med 44 vs. 70 pg/mL), suggesting that lead-exposed workers might develop adaptation mechanisms to reduce basal TNF-α release through downregulation processes proposed for this cytokine.

Lead exposure, IgE, and the risk of asthma in children

Lead (Pb) has adverse effects on our nervous system and renal systems. Young children are more vulnerable to Pb exposure. However, the role of low-level Pb exposure in the immune system and allergic diseases in children is not well established. The aims of this study are to investigate the associations between Pb exposure and allergic diseases; between Pb and immunoglobulin E (IgE) as an intervening variable; and gender-based differences. We used multistage stratified random sampling to recruit kindergarten children nationwide in Taiwan. Information about allergic diseases and environmental exposures was collected by questionnaire. We compared children with and without allergic diseases for blood Pb levels measured by inductively coupled plasma mass spectrometry. The association between blood Pb and allergic diseases was assessed by logistic regression and those between Pb and IgE by generalized linear models. We also conducted mediation analysis to evaluate how much risk of allergic diseases related to Pb exposure is explained by IgE. A total of 930 children completed specimen collections. There was a positive association between Pb and asthma. Blood Pb were also positively linked with serum IgE (β=0.26 kU/l per ln-unit increase Pb concentration; 95% CI 0.009-0.50 kU/l), after adjusting for potential confounders. Analyses stratified by gender revealed that blood Pb correlated with IgE only in boys (β=0.40 kU/l; 95% CI 0.03-0.76 kU/l). We estimated that 38% of the total effect of Pb exposure on asthma is mediated by IgE levels. In conclusion, Pb exposure is associated with both blood IgE and asthma in boys. Moreover, the effect of Pb exposure on asthma may be mediated by IgE levels.

The chemical disruption of human metabolism

BACKGROUND

Recent evidence highlights the reality of unprecedented human exposure to toxic chemical agents found throughout our environment - in our food and water supply, in the air we breathe, in the products we apply to our skin, in the medical and dental materials placed into our bodies, and even within the confines of the womb. With biomonitoring confirming the widespread bioaccumulation of myriad toxicants among population groups, expanding research continues to explore the pathobiological impact of these agents on human metabolism.

METHODS

This review was prepared by assessing available medical and scientific literature from Medline as well as by reviewing several books, toxicology journals, government publications, and conference proceedings. The format of a traditional integrated review was chosen.

RESULTS

Toxicant exposure and accrual has been linked to numerous biochemical and pathophysiological mechanisms of harm. Some toxicants effect metabolic disruption via multiple mechanisms.

CONCLUSIONS

As a primary causative determinant of chronic disease, toxicant exposures induce metabolic disruption in myriad ways, which consequently result in varied clinical manifestations, which are then categorized by health providers into innumerable diagnoses. Chemical disruption of human metabolism has become an etiological determinant of much illness throughout the lifecycle, from neurodevelopmental abnormalities in-utero to dementia in the elderly.

The association between serum lead and total immunoglobulin E levels according to allergic sensitization

BACKGROUND

Results of several studies showed that blood lead concentration is positively associated with total immunoglobulin E (IgE) value. However, no study has investigated whether allergic sensitization could be responsible for the association between lead exposure and total IgE value.

OBJECTIVE

We investigated whether there was difference in the association between lead exposure and the total IgE value, depending on the presence or absence of Dermatophagoides farinae sensitization.

METHODS

We used data obtained from the Korea National Health and Nutrition Examination Survey. Serum levels of heavy metals, such as mercury, cadmium, and lead, were measured. Total and D. farinae specific IgE levels were measured, and the urinary cotinine level was investigated. Information about sex, age, body mass index, and household income were also obtained. We analyzed the association between serum lead and total IgE levels, after adjusting other variables.

RESULTS

In an multivariate linear regression analysis, only the serum concentration of lead among the three heavy metals was positively associated with logarithmic transformed total IgE (coefficient [B], 0.026 [95% confidence interval {CI}], 0.008-0.044). When we performed the same analysis on groups divided by allergic D. farinae sensitization status, we found a significant positive association between serum lead and logarithmic transformed total IgE values in subjects with D. farinae sensitization (B, 0.043 [95% CI, 0.014-0.071]) but not in subjects without D. farinae sensitization (B, 0.015 [95% CI, -0.008 to 0.039]).

CONCLUSIONS

A positive association between the serum lead and total IgE levels was statistically significant in subjects with D. farinae sensitization, which indicated that the immunologic effects of lead exposure may be greater in people with allergic sensitization.

Environmental cigarette smoke exposure modulates IgE levels of Pb-exposed children

In urban areas with a predominance of early to mid-20th century housing stock, islands of children possessing blood lead levels (PbB) in excess of CDC guidelines (>10μg/dL) exist. Many of these children are also exposed to environmental tobacco smoke (ETS). The current study examined the impact of Pb-exposure (PbB levels of 1-55μg/dL) with/without concurrent ETS exposure on immune system function in 318 children aged 6-84 months from the urban area of Springfield-Greene County, MO. In this population, 36.5% of children possessed PbB levels >10μg/dL, 62.9% of children came from smoking homes, 51.9% of children were under 2 years of age, and the population was WIC eligible and predominantly of white, non-Hispanic ethnicity. Multiple immune function markers including cell counts, IgE levels, sCD25 (sIL2R) and IL4 concentrations, and titers to common childhood immunizations were analyzed for correlation with Pb and/or ETS exposure. Increased IgE levels (p<0.01) were found in children with PbB levels within CDC Classes II-IV - this finding was primarily attributable to elevated IgE levels in the subpopulation of children with concurrent Pb and ETS exposure. A trend (0.05<p<0.01) of increases in % total T-cells (p=0.06) was also found in children with concurrent elevated PbB levels and ETS exposure. This trend was not found in the subset of children without ETS exposure nor was it present in the analysis of the entire population set. Conversely, alterations in median values for % lymphocytes, % granulocytes, and % activated T-cells across Pb classes were present in the subpopulation of children expose to Pb alone (without concurrent ETS exposure) though a clear trend was not evident. In the entire population set, a statistically significant correlation between ETS and PbB levels was found. This study indicates that prior reports of a correlation between elevated PbB levels and serum IgE levels may be strongly influenced by exposure to ETS. Findings from this study also indicate that Pb is an immune modulator and PbB levels may be influenced by ETS exposure.

Review: Lead exposure in battery manufacturing and recycling in developing countries and among children in nearby communities

The battery industry is the largest consumer of lead, using an estimated 80% of the global lead production. The industry is also rapidly expanding in emerging market countries. A review of published literature on exposures from lead-acid battery manufacturing and recycling plants in developing countries was conducted. The review included studies from 37 countries published from 1993 to 2010 and excluded facilities in developed countries, such as the United States and those in Western Europe, except for providing comparisons to reported findings. The average worker blood lead level (BLL) in developing countries was 47 μg/dL in battery manufacturing plants and 64 μg/dL in recycling facilities. Airborne lead concentrations reported in battery plants in developing countries averaged 367 μg/m3, which is 7-fold greater than the U.S. Occupational Safety and Health Administration's 50 μg/m3 permissible exposure limit. The geometric mean BLL of children residing near battery plants in developing countries was 19 μg/dL, which is about 13-fold greater than the levels observed among children in the United States. The blood lead and airborne lead exposure concentrations for battery workers were substantially higher in developing countries than in the United States. This disparity may worsen due to rapid growth in lead-acid battery manufacturing and recycling operations worldwide. Given the lack of regulatory and enforcement capacity in most developing countries, third-party certification programs may be the only viable option to improve conditions.

Effects of environmental lead exposure on T-helper cell-specific cytokines in children

Lead (Pb) may alter T-lymphocyte reactivity in situ by preferentially enhancing the development of T-helper 2 (T(H)2)- and inhibiting T(H)1-lymphocyte development. These effects could result in dysregulation of the presence/availability of T(H)1- and T(H)2-associated cytokines. The aim of this study was two-fold, that is, to assess whole blood Pb levels in schoolchildren from Taiwanese communities that varied in degree of potential for Pb exposure and then ascertain if there were relationships between Pb exposure and changes in levels of key T(H)1 and T(H)2 cytokines. Grades 5 and 6 students were selected from four different community schools, i.e., one from: urban area with new homes; urban area with old homes; rural site with old homes; and area located near an oil refinery. Students at each site were further divided into healthy and respiratory allergy subgroups. Blood was collected and whole blood Pb levels and serum interferon (IFN)-γ, interleukin (IL)-12, -4, and -5 levels were determined. The results indicate no differences in whole blood Pb levels (<4 µg/dl) among students from urban and rural sites; these values were similar in the healthy and allergic subjects. Serum T(H)1 and T(H)2 cytokine levels also did not differ among/within the groups. In contrast, refinery children had significantly increased Pb levels (5.2-8.8 µg/dl) relative to any of the other sets' levels. Of these, children with allergies had serum T(H)2 cytokine levels significantly higher and T(H)1 cytokine levels significantly lower than their healthy counterparts. Oddly, though having elevated Pb levels, healthy refinery students did not display altered T(H)1 or T(H)2 cytokine levels relative to control student values. From this, we conclude that substantively increased whole blood Pb levels may promote T(H) cell dysregulation and alter the availability of key T(H)1 and T(H)2 cytokines, effects that could ultimately contribute to development of pulmonary allergic diseases.

Erythrocyte acetylcholinesterase activity as a surrogate indicator of lead-induced neurotoxicity in occupational lead exposure in Abeokuta, Nigeria

Dose-effect and dose-response relationships in occupational neurotoxicology are rarely studied by means of biochemical methods. In order to investigate the potential neurotoxic effects of lead during occupational exposure to this metal, the activity of erythrocyte acetylcholinesterase (AcChE), as well as blood pressure and pulse, were determined in various artisans in Abeokuta, Nigeria, who have been shown to be occupationally exposed to lead, and these were related to blood lead levels. AcChE activity in the artisans was inhibited to varying extents. While AcChE activity was inhibited to the tune of 39% in the male petrol station attendants, the inhibition amounted to 32% in female petrol station attendants. In other artisans, AcChE inhibition ranged from 31% in the welders to 38% in painters. The lowest inhibition of 15% was obtained in the panel beaters. Correlations, as calculated by Pearson's method, revealed a significant (p<0.001) inverse linear relationship between AcChE activity and blood lead levels (r=-0.40; y=-120.38x+13935.59; p<0.001). Blood pressure and pulse were not significantly different between control and lead-exposed subjects. Our findings suggest that erythrocyte AcChE activity could be used as a biomarker of lead-induced neurotoxicity in occupationally exposed subjects.

Pronounced susceptibility to infection by Salmonella enterica serovar Typhimurium in mice chronically exposed to lead correlates with a shift to Th2-type immune responses

Persistent exposure to inorganic lead (Pb) is known to adversely affect the immune system. In the present study, we assessed the effect of chronic Pb exposure on susceptibility to infection by the facultative intracellular pathogen Salmonella enterica serovar Typhimurium. Mice were exposed to 10 mM Pb-acetate in drinking water for approximately 16 weeks, resulting in a significant level of Pb in the blood (106.2+/-8.9 microg/dl). Pb exposure rendered mice susceptible to Salmonella infection, manifested by increased bacterial burden in target organs and heightened mortality. Flow cytometric analysis of the splenic cellular composition in normal and Pb-exposed mice revealed no gross alteration in the ratios of B and T lymphocytes or myeloid cells. Similarly, the capacity of B and T cells to upregulate the expression of activation antigens in response to mitogenic or inflammatory stimuli was not hindered by Pb exposure. Analysis of the ability of ex vivo-cultured splenocytes to secrete cytokines demonstrated a marked reduction in IFN-gamma and IL-12p40 production associated with Pb exposure. In contrast, secretion of IL-4 by splenocytes of Pb-treated mice was 3- to 3.6-fold higher than in normal mice. The increased capacity to produce IL-4 correlated with a shift in the in vivo anti-Salmonella antibody response from the protective IgG2a isotype to the Th2-induced IgG1 isotype. We conclude that chronic exposure to high levels of Pb results in a state of immunodeficiency which is not due to an overt cytotoxic or immunosuppressive mechanism, but rather is largely caused by a shift in immune responsiveness to Th2-type reactions.

Lead and immune function

The heavy metal lead is a widely deposited environmental toxicant known to impact numerous physiological systems, including the reproductive, neurological, hepatic, renal, and immune systems. Studies illustrating the capacity of lead to impair immune function and/or host resistance to disease date back to at least the 1960s. However, it has only been in recent years that lead has been recognized among a new category of immunotoxicants-those that dramatically shift immune functional capacity while producing only modest changes to immune cell populations and lymphoid organs. These relatively noncytotoxic immunomodulating chemicals and drugs represent the immunotoxic hazards most difficult to identify and problematic for risk assessment using historic approaches. As a result, such environmental factors are also among the most likely to contribute to chronic immune-related disease at relevant exposure levels. This review considers the animal and human evidence that lead exposure can produce a stark shift in immune functional capacity with a skewing predicted to elevate the risk of atopic and certain autoimmune diseases. At the same time, host defenses against infectious agents and cancer may be reduced. Age-based exposure studies also suggest that levels of blood lead previously thought to be safe, that is, below 10 microg/dl, may be associated with later life immune alterations.

Gene expression influences on metal immunomodulation

Heavy metals in the environment originate from both human activities and natural processes. Exposure to these metals can result in important changes to immune activity. Depending on the metal and dose, these changes can result in enhanced immune function, diminished immune responses, or altered responses that produce autoimmune disease. One of the intriguing aspects of these various phenomena are the multiple points of interaction with cellular machinery at which metals elicit these changes. The individual sections of this review serve to underscore the variety of targets that can be altered by exposure to heavy metals, and provide some comparisons between the effects of specific heavy metals on the immune system. These observations may ultimately lead us to a comprehensive understanding of the mechanisms by which metals alter the immune system, and may enable the development of countermeasures to offset these effects.

Dose-Dependent Modulation of the In Vitro Cytokine Production of Human Immune Competent Cells by Lead Salts

Lead pollution constitutes a major health problem that has been intensively debated. To reveal its effects on the immune response, the influence of lead on the in vitro cytokine production of human peripheral mononuclear blood cells was investigated. Isolated cells were exposed to lead acetate or lead chloride for 24 h in the presence of either heat-killed Salmonella enteritidis (hk-SE) or monoclonal antibodies (anti-CD3, anti-CD28, anti-CD40) as cell activators. Our results showed that while higher lead doses are toxic, lower ones evoke immunomodulatory effects. All tested lead doses significantly reduced cell vitality and/or proliferation and affected secretion of proinflammatory, T helper cell type (T(H))1 and T(H)2 cytokines. Expression of interferon (IFN)-gamma, interleukin (IL)-1beta, and tumor necrosis factor (TNF)-alpha was reduced at lower lead doses in both models of cell stimulation. Although hk-SE failed to induce detectable IL-4 levels, monoclonal antibody-induced IL-4, IL-6, and IL-10 secretion increased in the presence of lower lead doses. Also, levels of hk-SE-induced IL-10 and IL-6 secretion were increased at lower lead doses. Thus, exposure to lower doses leads to suppression of the T(H)1 cytokine IFN-gamma and the proinflammatory cytokines TNF-alpha and IL-1beta. The elevated production of IL-4 and/or IL-10 can induce and maintain a T(H)2 immune response and might contribute to increased susceptibility to pathologic agents as well as the incidence of allergic hypersensitivity and/or T(H)2-dominated autoimmune diseases.

Immune function biomarkers in children exposed to lead and organochlorine compounds: a cross-sectional study

BACKGROUND

Different organochlorines and lead (Pb) have been shown to have immunomodulating properties. Children are at greater risk for exposure to these environmental toxicants, but very little data exist on simultaneous exposures to these substances.

METHODS

We investigated whether the organochlorine compounds (OC) dichlorodiphenylethylene (DDE), hexachlorobenzene (HCB), hexachlorocyclohexane (gamma-HCH), the sum of polychlorinated biphenyls (SigmaPCBs) and Pb were associated with immune markers such as immunoglobulin (Ig) levels, white blood cell (WBC), counts of lymphocytes; eosinophils and their eosinophilic granula as well as IgE count on basophils. The investigation was part of a cross-sectional environmental study in Hesse, Germany. In 1995, exposure to OC and Pb were determined, questionnaire data collected and immune markers quantified in 331 children. For the analyses, exposure (OC and Pb) concentrations were grouped in quartiles (gamma-HCH into tertiles). Using linear regression, controlling for age, gender, passive smoking, serum lipids, and infections in the previous 12 months, we assessed the association between exposures and immune markers. Adjusted geometric means are provided for the different exposure levels.

RESULTS

Geometric means were: DDE 0.32 microg/L, SigmaPCBs 0.50 microg/L, HCB 0.22 microg/L, gamma-HCH 0.02 microg/L and Pb 26.8 microg/L. The SigmaPCBs was significantly associated with increased IgM levels, whereas HCB was inversely related to IgM. There was a higher number of NK cells (CD56+) with increased gamma-HCH concentrations. At higher lead concentrations we saw increased IgE levels. DDE showed the most associations with significant increases in WBC count, in IgE count on basophils, IgE, IgG, and IgA levels. DDE was also found to significantly decrease eosinophilic granula content.

CONCLUSION

Low-level exposures to OC and lead (Pb) in children may have immunomodulating effects. The increased IgE levels, IgE count on basophils, and the reduction of eosinophilic granula at higher DDE concentrations showed a most consistent pattern, which could be of clinical importance in the etiology of allergic diseases.