Membranous nephropathy due to skin-lightening cream

Low-level exposure to lead, cadmium and mercury, and histopathological findings in kidney biopsies

BACKGROUND

Lead (Pb), cadmium (Cd) and mercury (Hg) are all nephrotoxic metals, and a large part of the body burden of Cd and Hg is found in the kidneys. There are, however, few studies on associations between exposure to these toxic metals and renal biopsy findings, and none at low-level exposure.

AIM

To examine the hypothesis that low-level concentration of Pb, Cd or Hg in the kidneys is associated with histopathological changes in the kidneys.

METHODS

We determined concentrations of Pb, Cd and Hg in kidney, blood and urine in 109 healthy kidney donors, aged 24-70 years. The renal biopsies were scored according to the Banff classification regarding tubular atrophy, interstitial fibrosis, glomerulosclerosis, arteriosclerosis, and arteriolohyalinosis. Kidney function was assessed based on glomerular filtration rate (GFR) as well as urinary excretion of albumin, low molecular weight proteins, kidney injury molecule 1 and N-acetylglucose aminidase. Associations between metal concentrations and histopathological changes, were assessed in models also including age, sex and smoking.

RESULTS

The median kidney concentrations of Pb, Cd and Hg were 0.08, 13 and 0.21 μg/g, respectively. There were signs of tubular atrophy in 63%, interstitial fibrosis in 21%, glomerulosclerosis in 71%, arteriosclerosis in 47%, and arteriolohyalinosis in 36% of the donors, but, as could be expected, the histopathological findings were limited, mostly Banff grade 1. In models adjusted for age, sex and smoking, kidney Cd was positively associated with tubular atrophy (p = 0.03) and possibly with arteriolohyalinosis (p = 0.06). Kidney Hg was associated with arteriosclerosis (p = 0.004).

DISCUSSION AND CONCLUSIONS

The results suggest that even low levels of Cd in the kidney can induce a mild degree of tubular atrophy. This is in line with previous findings at high-level Cd exposure. The association between kidney Hg and renal arteriosclerosis was unexpected, and may be a chance finding.

Prevalence and Factors Associated with Acute Kidney Injury in Sub-Saharan African Adults: A Review of the Current Literature

Acute kidney injury (AKI) is a complex condition that can occur in both community and hospital settings and has many aetiologies. These aetiologies may be infectious, toxic, surgical, or related to the different management methods. Although it is a major public health problem worldwide, it must be emphasised that both its incidence and mortality rate appear to be very high in sub-Saharan African (SSA) countries compared to developed countries. The profile of AKI is very different from that of more developed countries. There are no reliable statistics on the incidence of AKI in SSA. Infections (malaria, HIV, diarrhoeal, and other diseases), nephrotoxins, and obstetric and surgical complications are the main aetiologies in Africa. The management of AKI is costly and associated with high rates of prolonged hospitalisation and in-hospital mortality.

Inhibition of Tyrosinase by Mercury Chloride: Spectroscopic and Docking Studies

Inorganic mercury compounds have been used in skin-lightening products since ancient times. Although a previous study demonstrated that mercury impeded the transfer of Cu²⁺ to the apotyrosinase, the effect of mercury on tyrosinase is still unclear. In the present study, the mechanism of mercury chloride (HgCl₂) induced inactivation of tyrosinase was investigated for the first time. The IC₅₀ values were 29.97 and 77.93 μmol/L for monophenolase and diphenolase, respectively. A kinetic analysis revealed that HgCl₂ inhibited tyrosinase activity in an irreversible non-competitive manner. The strong intrinsic fluorescence quenching suggested that the formation of the HgCl₂-tyrosinase complex induced conformational changes of the enzyme, and HgCl₂ had only one single binding site or a single class of binding site on tyrosinase. The molecular docking and further experiments demonstrated that HgCl₂ bound to the amino residuals (His) in the catalytic center of tyrosinase. To our knowledge, these findings presented in this paper were the first evidence of the direct interactions between HgCl₂ and tyrosinase, which provided a deep understanding of the inhibition mechanism of mercury on tyrosinase.

Use of skin-lightening products among selected urban communities in Accra, Ghana

BACKGROUND

The practice of skin lightening has been reported from North America, Europe, Asia, and Africa. In literature, some prevalence rates exceed 50%, and both sexes are involved. Common agents used include hydroquinone, mercury, corticosteroids, and caustic agents. The agents are easily accessible and affordable with very little regulation. Cutaneous and systemic side effects occur but do not appear to be a deterrent, as the notion of light skin as a surrogate for beauty is strong. In Ghana, anecdotal reports of high bleaching rates among certain urban communities resulted in a study supported by the Food and Drugs Authority to determine various facets of this practice.

METHODS

A cross-sectional study among adults in selected urban fishing communities of Accra was undertaken. Consecutive cases were enrolled after written informed consent. A questionnaire was administered, followed by physical examination and clinical photographs. Descriptive statistics were used to analyze the data.

RESULTS

Of the 555 participants from the three communities, prevalence was 279 (50.3%). Duration of use ranged from 2 months to 17 years. Approximately 212 (76%) used more than one product, and 231 (82%) used agents on their face and body. Dermatological features were hypopigmentation 270 (96.8%), other color changes including ochronosis 241 (86.4%), changes in consistency 141 (50.3%), striae 157 (56.3%), and infections 42 (15.1%).

CONCLUSIONS

The prevalence of skin bleaching was 50.3% in these communities, which is high considering the adverse effects from the practice. We recommend regulation of products by enforcing the law, more education, and a population prevalence study.

Mercury content in marketed cosmetics: analytical survey in Shijiazhuang, China

CONTEXT

Mercury is one of the skin-lightening ingredients in cosmetics as mercury ions are thought to inhibit the synthesis of the skin pigment melanin in melanocyte cells.

OBJECTIVE

The objective of this study was to evaluate the mercury levels of cosmetics currently marketed in Shijiazhuang, a northern city in China.

METHODS

We collected 146 random cosmetic samples and analyzed for mercury concentrations or levels by cold vapor atomic absorption spectrometry.

RESULTS

Among the 146 samples, 134 (91.8%) were positive for mercury, and the concentrations of mercury ranged from not detectable to 592 ng/g. Cosmetic samples for children and babies had the highest detection rate (100%), followed by shampoo and hair conditioner (92.3%) and skin-lightening cream (92.0%). All of them were lower than the acceptable limit (1 μg/g) in China.

DISCUSSION AND CONCLUSIONS

Cosmetics for skin had the highest mean mercury content (45 ng/g), followed by hair products (42.1 ng/g). The concentrations of mercury detected in samples were lower than the current legal limit in China, indicating it may not pose a risk to consumers.

Nephrotic syndrome of minimal change disease following exposure to mercury-containing skin-lightening cream

A 28-year-old female suffered from nephrotic syndrome after a long-term use of mercury-containing, skin-lightening cream. The blood and urinary mercury content of this patient increased with use. Renal biopsy showed minimal change disease. Her symptoms were relieved 6 months after discontinuing use of the cream and receiving sodium dimercaptosulfonate and glucocorticosteroid treatments. Proteinuria disappeared, and blood and urinary mercury levels returned to normal. Previous reports of nephrotic syndrome caused by mercury-containing, skin-lightening creams have mostly been identified as be.ing due to membranous nephropathy. Minimal change disease has been reported in a few case reports published in the English language. Here we report a case of nephrotic syndrome with minimal change disease following exposure to a mercury-containing, skin-lightening cream. We also reviewed relevant published reports to summarize clinical features and treatments and to explore the possible mechanisms involved.

Inorganic mercury poisoning associated with skin-lightening cosmetic products

INTRODUCTION

Mercury and mercury salts, including mercurous chloride and mercurous oxide, are prohibited for use in cosmetic products as skin-lightening agents because of their high toxicity. Yet, the public continue to have access to these products.

METHODS

Reports of skin-lightening cosmetic products containing mercury and cases of mercury poisoning following the use of such products were identified using Medline (1950 - 28 March 2011) with mercury, mercury compounds, mercury poisoning, cosmetics and skin absorption as the subject headings. These searches identified 118 citations of which 31 were relevant.

TOXICOKINETICS

The rate of dermal absorption increases with the concentration of mercury and prior hydration of the skin. The degree of dermal absorption varies with the skin integrity and lipid solubility of the vehicle in the cosmetic products. Ingestion may occur after topical application around the mouth and hand-to-mouth contact. After absorption, inorganic mercury is distributed widely and elimination occurs primarily through the urine and feces. With long-term exposure, urinary excretion is the major route of elimination. The half-life is approximately 1-2 months.

FEATURES

The kidneys are the major site of inorganic mercury deposition; renal damage includes reversible proteinuria, acute tubular necrosis and nephrotic syndrome. Gastrointestinal symptoms include a metallic taste, gingivostomatitis, nausea and hypersalivation. Although penetration of the blood-brain barrier by inorganic mercury is poor, prolonged exposure can result in central nervous system (CNS) accumulation and neurotoxicity. Inorganic mercury poisoning following the use of skin-lightening creams has been reported from Africa, Europe, USA, Mexico, Australia and Hong Kong. Nephrotic syndrome (mainly due to minimal change or membranous nephropathy) and neurotoxicity were the most common presenting features. As mercury-containing cosmetic products can contaminate the home, some close household contacts were also reported to have elevated urine mercury concentrations.

ASSESSMENT

Prevention from further exposure is the first step. Cream users and their close contacts should be evaluated for evidence of mercury exposure, the presence of target organ damage and the need for chelation treatment. Laboratory evaluation of affected subjects should include a complete blood count, serum electrolytes, liver and renal function tests, urinalysis, urine and blood mercury concentrations. Since blood mercury concentrations tend to return to normal within days of exposure, blood samples are useful primarily in short-term, higher-level exposures. Estimation of the urine mercury concentration is the best marker of exposure to inorganic mercury and indicator of body burden. A 24-hour urine for measurement of mercury excretion is preferred; a spot urine mercury concentration should be corrected for creatinine output.

MANAGEMENT

Chelation therapy is indicated in patients with features of mercury poisoning and elevated blood and/or urine mercury concentrations. Unithiol (2,3-dimercapto-1-propanesulfonic acid, DMPS) is the preferred antidote though succimer (dimercaptosuccinic acid, DMSA) has also been employed.

CONCLUSIONS

The use of mercury in cosmetic products should be strictly prohibited. The public should be warned not to use such products as their use can result in systemic absorption and accumulation of mercury causing renal, gastrointestinal and CNS toxicity.

Widespread use of toxic skin lightening compounds: medical and psychosocial aspects

Hyperpigmentation disorders and skin lightening treatments have a significant impact on the dermatologic, physiologic, psychologic, economic, social, and cultural aspects of life. Skin lightening compounds, such as hydroquinone and topical corticosteroids, are often used to treat hyperpigmentation disorders, such as melasma, or lighten skin for cosmetic purposes. Despite their established effectiveness, a multitude of dermatologic and systemic complications have been associated with these agents. Regulatory agencies have also recognized the adverse effects of skin lighteners and many countries around the world now forbid the production and sale of these compounds, although this prohibition has not significantly curtailed distribution. Dermatologists and users of cosmetic products should be aware of the various components in bleaching compounds, their potential adverse effects, and alternative options for skin lightening.

Accumulation of mercury in ovaries of mice after the application of skin-lightening creams

Skin-lightening creams are being increasingly used by women in particular, worldwide in an attempt to whiten their skin. Men and older people use these creams to remove age spots or other pigmentation disorders. Several studies have reported the presence of high mercury levels in skin-lightening cream. Women, especially pregnant and nursing mothers, who use these creams are at risk of mercury toxicity because long-term exposure can cause permanent neurological damage, nephrological disorders, fertility problems, and birth defects. Early exposure usually has no clinical symptoms. Mercury levels were measured in a total of 49 ovary tissue samples. The mean mercury contents in the ovaries of non-treated mice (11.70 +/- 13.38 ng/g) were compared to mice treated with Rose skin-lightening cream samples (2,471.92 +/- 1,336.31 ng/g) and those treated with Fair & Lovely skin-lightening creams (58.47 +/- 39.51 ng/g). The mercury content in the ovary tissues increased with number of cream applications and were highest in the ovaries of mice treated twice a day with Fair & Lovely (87.79 +/- 26.20 ng/g) and once a day with Rose (3,515.61 +/- 1,099.78 ng/g). Our data indicate that dermal exposure to mercury can result in a significant accumulation in the ovaries of mice following the application of skin-lightening cream. This may cause alterations in reproductive behavior and contribute to infertility or ovarian failure. Of course, these results need to be confirmed by further research. Imported or locally made skin-lightening creams are widely available in Saudi market. It would be ideal to ban the sale of these creams but unfortunately, advertisements in the mass media presenting celebrities and beauty specialists make these products more popular. Alternatively, public health authorities should encourage more reliance on prescribed creams for the treatment of skin pigmentation problems.

Skin bleaching: highlighting the misuse of cutaneous depigmenting agents

Hydroquinone and other cutaneous depigmenting agents are widely used by dermatologists to treat pigmentary disorders. On 29 August 2006, the US Food and Drug Administration (FDA) published a monograph in the US Federal Register proposing to ban all hydroquinone products that have not been approved via a New Drug Application process. Reports in the scientific literature on the occurrence of exogenous ochronosis, in relation to the use of hydroquinone, was one of the concerns expressed by the FDA in relation to this agent. However, a review of the English-language scientific literature reveals that most of the reported cases of hydroquinone-induced exogenous ochronosis occurs in Africa, where the cultural practice of skin bleaching is highly prevalent. Skin bleaching is the practice of applying hydroquinone and/or other depigmenting agents to specific or widespread areas of the body, the primary function being to lighten normally dark skin. This practice typically occurs in men and women with Fitzpatrick skin phototypes IV to VI. It is a dangerous practice associated with a diverse range of side-effects, including mercury poisoning. Thus, this current discussion within the dermatological community on the safety of hydroquinone provides a unique opportunity to raise awareness about skin bleaching.

Does low mercury containing skin-lightening cream (fair & lovely) affect the kidney, liver, and brain of female mice?

Fair & Lovely is an over-the-counter skin-lightening cream sold widely in Saudi markets. Its mercury content is 0.304+/-0.316 microg/g, in the range of 0.102 to 0.775 microg/g. This study was designed to evaluate its toxic effects on mice. The cream was applied on mice for a period of 1 month at different intervals. Mercury levels were measured in the liver, kidney, and brain tissue samples of a total of 75 adult female CD1 mice by Atomic Absorption Spectrophotometer coupled to a Vapor Generator Accessory. The mean mercury concentrations in the tissues of the treated mice were 0.193+/-0.319 microg/g; whereas for the control group, it was 0.041 microg/g+/-0.041microg/g. While the kidney was found to have the highest mercury content, the brain was found to have the lowest content. Treated mice showed a significant reduction in body weight. Marked histological changes were clearly noted in the kidney and, to a lesser extent, in the brain and liver. These results indicate that although Fair & Lovely mercury content is less than the U.S. Food and Drug Administration (FDA) permissible limits histopathological changes in the brain, kidney, and liver tissues are evidence of its possible toxicity.

Skin lightening and its complications among African people living in Paris

BACKGROUND

Complications caused by skin lightening practices have not been systematically studied in Europe.

OBJECTIVE

Our aim was to assess the complications of skin lightening among people of African descent living in Paris.

METHODS

This was a descriptive study. All patients presenting with complications from skin lightening procedures underwent a complete clinical examination and were questioned about their practice.

RESULTS

Forty-six patients from various African countries (39 women, 7 men) presented with skin changes suggestive of side effects from skin lightening practices. The complications seemed mainly related to the use of clobetasol and hydroquinone.

LIMITATIONS

The selection bias does not allow assessment of uncomplicated skin lightening.

CONCLUSION

Complications arising from skin lightening practices represent a significant health problem for people of African descent living in Paris.

Drug-induced glomerulopathies

Normal renal function depends upon an intact glomerular apparatus. Many drugs and chemicals are capable of damaging the glomerulus, causing its increased permeability to large molecules. Glomerular lesions are usually responsible for proteinuria and the nephrotic syndrome. This also holds true for the drug-induced glomerulopathies, of which membranous glomerulo-nephritis is the most frequent type of lesion encountered. Apart from this, several cases of different glomerular changes such as focal segmental glomerulosclerosis and crescentic glomerulonephritis have also been reported. The drug-induced glomerulopathies are probably immune mediated. This is, for instance, reflected in the fact that patients with drug-induced nephritic syndrome frequently have the HLA-B8 and DR3 antigens. In depth information is provided for the previously mentioned disorders.

A whitened face woman with nephrotic syndrome

Skin whitening cream from developing countries is a recognized source of chronic mercury poisoning. The authors report on a 34-year-old Indonesian domestic helper who presented with nephrotic syndrome secondary to membranous nephropathy. It was subsequently found that she used a skin whitening cream regularly that was found to contain a mercury level of almost 2,000 times above the allowable limit. Her blood and urinary mercury levels were both grossly elevated. Her symptoms improved after she stopped using the cream. However, she returned to her home country before chelating therapy could be arranged. Because mercury-containing skin products are still widely available in developing countries, the use of these products should be considered a possible cause of membranous nephropathy in immigrants from those countries.

Mercury poisoning associated with a Mexican beauty cream

OBJECTIVES

To describe demographic characteristics, patterns of use, and symptoms associated with mercury poisoning among persons who used a Mexican beauty cream containing mercurous chloride and to estimate the prevalence of cream use in Texas near the Mexico border.

DESIGN

Case series and cross-sectional survey.

SETTING

Border communities of Arizona, California, New Mexico, and Texas.

PARTICIPANTS

Persons who used the cream and contacted a health department in response to announcements about the cream and households that participated in the Survey of Health and Environmental Conditions in Texas Border Counties and Colonias, 1997.

MAIN OUTCOME MEASURES

Urine mercury concentrations, self-reported symptoms, and prevalence of cream use among households.

RESULTS

Of 330 cream users who contacted their health department, 96% were women, and 95% were Hispanic. The mean urine mercury concentration was 146.7 microg/L (reference range : 0-20 microg/L). In 5% of 2,194 randomly selected Texas households near the Mexico border, at least 1 person had used "Crema de Belleza-Manning" (Laboratorios Vida Natural, S.A., Tampico, Tamaulipas, Mexico) in the previous year.

CONCLUSIONS

Most cream users had increased urine mercury concentrations. Cream use was common in Texas near the Mexico border. Physicians should consider toxicity in patients with neurologic symptoms of unclear cause and use public health departments when investigating unusual illnesses.

T lymphocytes in mercury-exposed workers

In this work we have investigated the changes in T-helper and T-suppressor cells and T-cell proliferative response to phytohemagglutinin (PHA) in mercury-exposed workers. The study group consisted of 33 workers from a mercury-producing plant with a mean age of 29 years and a mean exposure period of 19 months. At the time of testing, and for the three previous months, the exposed population had urinary mercury levels below the currently accepted limit of 50 micrograms/g creatinine. A reverse CD4+/CD8+ ratio was observed in the mercury-exposed individuals which was characterized by a reduction in the number of CD4+ lymphocytes. No changes were observed in the proliferative response of lymphocytes from exposed individuals to PHA. Similarly, no proliferative response was observed when lymphocytes from normal individuals were cultivated in the presence of serum from the exposed workers. We found no correlations between lymphocytes changes and urinary mercury concentrations, time of exposure or the age of the workers.

B lymphocytes in mercury-exposed workers

We have investigated the number of B lymphocytes in mercury-exposed workers. The study group consisted of 33 workers from a mercury-producing plant, mean age 27 years and a mean exposure period 19 months. At the time of testing and for the three previous months, the exposed persons had urinary mercury levels below the currently accepted limit of 50 micrograms g creatinine. A significant reduction in the number of B lymphocytes was observed in the mercury-exposed individuals. We found no correlation between B lymphocytes changes and urinary mercury concentrations, length of exposure or age of the workers.

Chronic effects of methylmercury in rats. II. Pathological aspects

Chronic effects of methylmercury (MeHg) were examined pathologically in male Wistar rats fed on diet containing 0, 1 or 5 ppm Hg (as MeHg) for two years. Organs including the central nervous tissues were examined histopathologically using hematoxylin and eosin (H & E), Klüver-Barrera (KB), PAS or phenol-congo red stains. The peripheral nerve system tissues were also examined, using H & E and trichrome stains. Furthermore, immunoglobulins of renal specimens were demonstrated by direct immunofluorescence microscopy. Localization of mercury in the paraffin-embedded sections of the nervous tissue, kidney, liver, pancreas, spleen and testis was demonstrable by the photoemulsion histochemical method. In the 5 ppm group, mercury was readily detectable in tissues of the rats exposed for one year, one and half years, two years and two and half years. Mercury was detected in the cells of the brain such as neurons, neuroglial cells, and phagocytes, and also in most organs, particularly in the epithelium of renal tubules, liver cells, myocardium, in the macrophages of pancreas, spleen and testis. In the 1 ppm group, mercury was detectable in the epithelium of renal tubules and liver cells. Fibrosis of the glomeruli was found in the rat group given a high dose of methylmercury with all experimental methods. Granular IgG, IgM and C3 deposits were demonstrated in the glomeruli by direct immunofluorescence microscopy. The etiology of the pathological changes of glomeruli was suspected to be autoimmune glomerulopathy due to inorganic mercury filtration for a long time. It was difficult to determine the clinical signs and symptoms and pathological changes in the nervous system in spite of the deposition of mercury in the brain.

Mercury content in skin-lightening creams and potential hazards to the health of Saudi Women

It seems evident from a wealth of scientific research that mercury is toxic. Because of the nature of the Saudi markets, different brands of skin-lightening creams are widely available. In this study, 38 skin-lightening cream samples were collected and analyzed for mercury by inductively coupled plasma spectrometry after an acid digestion procedure. About 45% of the tested skin-lightening cream samples contained mercury at levels well above the FDA's acceptable limit of 1 ppm. These findings are alarming and have wide legal and educational implications for Saudi Arabia in particular and developing countries in general. Further investigation for possible adverse health effects is also needed.

Murine strain differences in response to mercuric chloride: antinucleolar antibodies production does not correlate with renal immune complex deposition

Mercuric chloride (HgCl2) induces the production of antinucleolar antibodies (ANucA) in susceptible strains of mice. Responder strains bearing the H-2(5) haplotype as well as several ANucA resistant strains have been shown to develop renal immune complex deposits after HgCl2 treatment. Sera obtained throughout 12 to 16 weeks of HgCl2 treatment from mice of four ANucA responder strains (A.SW/SnJ, A.CA/SnJ, DBA/1J, and P/J) and one ANucA-resistant strain (C57BL/10SnJ) were examined for ANucA production. Terminal sera were also tested for the presence of anti-glomerular basement membrane antibodies, and the kidneys were examined for the deposition of IgG and C3. Only one strain, A.SW, developed significant deposits of IgG in the renal glomeruli, although all four responder strains exhibited similar ANucA induction/production profiles. The differences seen by direct immunofluorescence assay (IFA) in renal immune complex deposition between the A.SW and histocompatibility congenic A.CA mice were corroborated by individually eluting and then quantitating the deposited IgG from renal tissues of Hg-treated A.SW and A.CA mice as well as control A.SW mice. The average amount of IgG eluted from A.SW renal tissue was significantly greater than that eluted from either A.CA or control A.SW renal tissues. All eluates from Hg-treated animals gave only a nucleolar fluorescence pattern when assayed by indirect IFA against a panel of rat organ tissues. In summary, no correlation was found between ANucA production and renal IgG deposition in response to treatment with HgCl2.

Influence of heavy metal ions on antibodies and immune complexes investigated by dynamic light scattering and enzyme-linked immunosorbent assay

The effect of Cd2+, Pb2+, Hg2+ and Cu2+ on the aggregation behaviour of monoclonal rat-IgG1-anti-mouse antibodies (kappa-light chain specific) and their antibody-antigen complexes with monoclonal mouse-IgG1 is reported. Investigations were done using the dynamic light scattering method. Cd2+ ions affected the hydrodynamic properties of the antibodies and the immune complex formation very little. More than 4 Cu2+ ions per antibody molecule led to large insoluble aggregates. Pb2+ ions also interacted with antibodies and immune complexes. Instead of "monomeric' antibodies (Ab) or immune complexes (Ab1Ag1), large soluble aggregates were detectable in the solution. Hg2+ ions induced complex formation with 3-4 antibodies per aggregate. Possible kinds of interaction are discussed. Additionally, we tested the antigen binding activity of metal-treated antibodies in ELISA-tests. The Sandwich ELISA technique was used to investigate the serological activity of the metal-treated antibodies, i.e., the reaction with the specific antigen. For these experiments we used the same monoclonal antibodies, mouse-IgG1 and rat-IgG1-anti-mouse. The influence of the above mentioned heavy metal ions was investigated up to a 10-fold molar excess over the antibody concentration. Even at these "unphysiological' high metal ion concentrations an inhibition of the antibody-antigen binding activity was not detectable.

Acute glomerulonephritis, Henoch-Schönlein purpura and dental amalgam in Swedish children: a case-control study

The issue of adverse health effects from dental amalgam and the concurrent low-dose exposure to inorganic mercury have been scrutinized by several Swedish expert groups during the past years. Only rarely have amalgam fillings in children been related to health effects. Experimental studies in genetically disposed animals have shown that low doses of inorganic mercury can induce autoimmune glomerulonephritis. The present case-control study included 31 children with acute glomerulonephritis and 33 with Henoch-Schönlein purpura retrieved from an in-patient register for the period 1973-1992 at the county hospital in Halmstad, Sweden. The median age was 10 and 9 years, respectively, for the two diagnostic groups. Dental clinics reported amalgam burden of the patients during the year before the date of diagnosis. Corresponding data were obtained for three randomly selected controls for each case, drawn from the case records of the same dental clinics, with matching for age and sex. Odds ratios (95% confidence interval) were 1.42 (0.49, 4.11) for Henoch-Schönlein purpura, 0.59 (0.25, 1.38) for acute glomerulonephritis and 0.84 (0.40, 1.75) for both diseases combined. The results of this study did not indicate increased disease risk in relation to amalgam burden.

Nephrotoxicity of xenobiotics

Nephrotoxicity can be grouped by the xenobiotics place of action, by the clinical presentation or by the generic toxic effect. The latter can be dose related, indirect, idiosyncratic or allergic. Nephrotoxicity of lithium, demeclocycline, aminoglycosides, cyclosporine, mercuric ion, nonsteroidal anti-inflammatory drugs, methoxyflurane, ethylene glycol, D-penicillamine and methicillin is reviewed in light of all these three viewpoints, but emphasis is on toxic mechanisms.

Dental amalgam, low-dose exposure to mercury, and urinary proteins in young Swedish men

Chronic exposure to inorganic mercury can cause kidney injury. Evidence gained from occupational medicine indicates that individuals who are exposed to only environmental sources, including amalgam tooth fillings, are at very little risk. Animal experiments, however, have revealed glomerular lesions of immunologic origin after low-dose exposure to inorganic mercury. In this study, the association between the number of amalgam tooth surfaces, urinary mercury, and proteinuria was explored in a sample of 48 randomly selected, apparently healthy male students who were 17-22 y of age. Presence of any of the following proteins in two separate urine samples was considered to be potentially indicative of any tubular and/or glomerular lesion: albumin, alpha-1-microglobulin (HC-protein), kappa and lambda light chains, and N-acetyl-beta-D-glucosaminidase. No significant relationship was found between any of the proteins and amalgam or urinary mercury. The results of this study did not suggest that amalgam fillings cause kidney dysfunction in humans.

Measurement of the respiratory burst and chemotaxis in polymorphonuclear leukocytes from mercury-exposed workers

The chemotactic and nitroblue tetrazolium reducing activities of neutrophils from 48 mercury-exposed workers were examined and compared with those of non-exposed, age- and sex-matched individuals. At the time of testing, the exposed population had a mean (+/- s.d.) urinary mercury concentration of 24.0 +/- 20.1 micrograms g-1 creatinine and in 44 of these workers urinary mercury levels were below the accepted threshold level (TLV) of 50 micrograms g-1 creatinine. The two neutrophil functions were significantly reduced in the mercury-exposed workers compared with the controls. In 28 of these workers, chemotaxis was re-evaluated 6 months later. During the intervening 6 months, the level of hygiene was improved throughout the plant and urinary mercury concentrations were determined monthly in each worker. Despite a significant reduction in urinary mercury concentrations, neutrophil migration did not return to within the normal range. These results suggest that 'safe' level mercury exposure may lead to impairment of neutrophil function.

Polymorphonuclear phagocytosis and killing in workers exposed to inorganic mercury

The ability of neutrophils to phagocytose and kill Candida species as well as the splenic phagocytic function were investigated in workers from a mercury-producing plant. In the neutrophil phagocytosis study, two species of Candida were used since in individuals with myeloperoxidase deficiency neutrophils are unable to kill Candida albicans, while Candida pseudotropicalis can be effectively lysed. Phagocytosis of both antigens and splenic phagocytic function were normal in all the workers studied. However, following ingestion of the organisms there was considerable reduction in the ability of neutrophils from exposed workers to kill both species of Candida, and this was not explained by a mild impairment of phagocytosis. After improvement in the hygiene conditions in the factory, a new evaluation was performed, 6 months later, in the same workers and urinary mercury concentrations were determined monthly in each worker. Despite a significant reduction in urinary mercury concentrations, a greater impairment in the ability of neutrophils to kill C. albicans was observed. The killing of C. pseudotropicalis presented no further impairment when compared to the previous evaluation. These results suggest that impairment of the lytic activity of neutrophils from workers with urinary mercury concentrations within the safe level for exposed population is due, at least in part, to some interference with myeloperoxidase activity. In addition, the mercury-NADPH complex, once formed, could limit the utilization of reduced pyridine nucleotides by NADPH-dependent enzymes such as NADPH oxidase, thereby inhibiting the PMN respiratory burst.

Immune factors, dental amalgam, and low-dose exposure to mercury in Swedish adolescents

Occupational high-dose exposure to metallic mercury can cause immune disturbances in sensitive individuals. Whether low-dose exposure to inorganic mercury from dental amalgam has this effect in humans is one of the issues related to the concept of oral galvanism and is supported by results of animal studies. This study explored some cellular immune factors (B- and T-lymphocytes, T4, T8, monocytes, neutrophilic, eosinophilic, and basophilic granulocytes, and large unstained cells) and some humoral immune factors (immunoglobulins IgG, IgG1, IgG2, IgG3, IgG4, IgA, IgM, IgE, albumin, alfa-1-antitrypsin, orosomucoid, haptoglobin, and antinuclear antibodies) in 41 healthy 15-y-old schoolchildren. The relationship between these factors and amalgam fillings and mercury concentrations in plasma (P-Hg) were investigated. A low, but significant correlation (r = 0.40, p < .05) was found between the number of amalgam surfaces and the P-Hg values, which were low for both sexes (median value = 1.8 nmol/l). There was no significant influence of the number of amalgam surfaces or P-Hg on the immune factors tested, except random findings. The girls had significantly higher values of T8, IgG, and IgG1 than the boys.

Immunoglobulin levels in workers exposed to inorganic mercury

The serum immunoglobulin (IgG, IgM and IgA) concentrations of 44 mercury-exposed workers were examined and compared with those of non-exposed, age- and sex-matched individuals. At the time of testing, the exposed population had a mean (+/- S.D.) mercury urinary concentration of 24.7 +/- 19.1 and in 40 of them urinary mercury levels were below the currently accepted limit of 50 micrograms/g creatinine. Increased IgG, IgA and IgM levels were found in the mercury-exposed individuals and in 16, a second evaluation was performed six months later. During the intervening six months, the level of hygiene was improved throughout the plant, and urinary mercury concentrations were determined monthly in each worker. Despite a significant reduction in mercury urinary concentrations, serum immunoglobulin levels did not return to the normal range. There was no correlation between the length or level of exposure and the immunoglobulin levels. Liver protein synthesis, as studied by factor V, prothrombin time, prealbumin and transaminase activity, was normal and liver injury, as evaluated by serum aspartate and alanine aminotransferase activities (AST and ALT, respectively), was not observed. No haematological abnormalities were noted. These results indicate that "safe" levels of mercury exposure may lead to humoral immunological stimulation.

Membranous nephropathy in two human leukocyte antigen-identical brothers

We describe two Hispanic brothers with membranous nephropathy who had nephrotic syndrome in the first 2 years of life. Secondary causes of membranous nephropathy were excluded by clinical history and laboratory data. The occurrence of membranous nephropathy in these two young brothers, as well as in other familial cases reported to date, suggests an X-linked mode of inheritance.

Dose-response studies in murine mercury-induced autoimmunity and immune-complex disease

Female SJL/N mice were given either 5.0, 2.5, 1.25, or 0.625 mg mercuric chloride per liter drinking water (ppm HgCl2). Serum antinucleolar antibodies (ANuA) of the IgG class were seen in mice given at least 1.25 ppm HgCl2 for 10 weeks, a dose which corresponded to a mean renal mercury concentration, as measured with atomic absorption spectrophotometry, of 2.4 +/- 0.43 microgram Hg/g wet weight (ppm Hg; means +/- 1 SD). At a dose of 5.0 ppm HgCl2 all mice showed IgG ANuA with a mean titer of 1:846 and a mean renal mercury concentration of 14.8 +/- 3.9 ppm. Significantly increased titers of granular IgG deposits, corresponding to immune-complex (IC) deposits, developed in the renal mesangium of mice given 5.0 ppm HgCl2. Mice with heavy mesangial IgG deposits showed a mild glomerular endocapillary cell proliferation and widening of the mesangium. Renal vessel wall IgG deposits were found only in mice given 5.0 ppm HgCl2, whereas such deposits were seen in splenic and cardiac arteries of mice receiving 1.25 ppm or more of HgCl2. The renal and splenic mercury concentration was significantly increased in all groups of mercuric chloride-exposed mice and correlated with the dose. We conclude that 10 weeks peroral treatment with mercuric chloride in drinking water is able to elicit autoimmunity and IC disease in genetically homogeneous, mercury-sensitive mice at a body burden similar to that reported in some occupationally exposed humans.

The treatment of melasma. 20% azelaic acid versus 4% hydroquinone cream

The efficacy of 20% azelaic acid cream and 4% hydroquinone cream, both used in conjunction with a broad-spectrum sunscreen, against melasma was investigated in a 24-week, double-blind study with 329 women. Over the treatment period the azelaic acid cream yielded 65% good or excellent results; no significant treatment differences were observed with regard to overall rating, reduction in lesion size, and pigmentary intensity. Severe side effects such as allergic sensitization or exogenous ochronosis were not observed with azelaic acid.

Membranous nephropathy caused by mercury-containing skin lightening cream

A 46 year old woman developed membranous nephropathy following the use of a mercury-containing skin lightening cream. This association has not been reported in the literature for over a decade and apparently never from this country. It is important that clinicians are aware of this usually eminently treatable cause of the nephrotic syndrome as it is likely to be missed unless specifically enquired for.

Membranous glomerulonephritis

In a clinicopathological survey of idiopathic membranous glomerulonephritis (MGN) in 85 patients the predominance of the condition among men could be at least partly explained by an increased risk of exposure to organic solvents and heavy metals in the course of work. This may have implications for the advice given to these patients after MGN has been diagnosed. The selectivity of proteinuria could predict the likely outcome of the disease.

Distribution of [3H]-D-penicillamine in mouse kidney. An autoradiographic study

3H-labeled D-penicillamine has been injected in mice in order to study by autoradiography its distribution in the kidney. The results show heavy accumulation of the drug in the epithelial cells of the proximal tubules of the kidney, whereas glomeruli and distal tubules do not show any significant accumulation. This peculiar tropism of penicillamine to proximal tubules is entirely consistent with the Heymann's nephritis model suggested by Bacon as a pathogenetic model for penicillamine-induced nephropathy.

Cosmetic and dermatology: bleaching creams

Bleaching creams containing hydroquinone are modestly effective in treating some pigmentary disorders. In 2.0% to 5.0% concentrations, hydroquinone is generally quite safe; allergic contact dermatitis may rarely necessitate stopping therapy. Achieving successful results depends on diligent, long-term treatment by patients who have carefully instructed in methods of use as well as protection from sun exposure. Supplemental use of topical corticosteroids, salicylic acid, or tretinoin, under a physician's supervision, improves the results considerably. However, even with the most persistent and careful management, most patients experience at best only partial improvement.