A case-control study of oral cancer and pre-diagnostic concentrations of selenium and zinc in nail tissue

Selenoprotein genetic variants may modify the association between serum selenium and oral cancer risk

OBJECTIVE

The relationship between selenium (Se) and oral cancer is still controversial, and the selenoprotein genes play crucial roles in selenium metabolism. We aim to investigate the potential effect of selenoprotein genes (including GPx and TXNRD) in the association of serum Se with oral cancer risk.

METHODS

A case-control study including 235 oral cancer cases and 406 controls from September 2011 to December 2018 was conducted in Fujian, China. The peripheral blood samples were obtained from each participant. Genotyping was performed by MassARRAY system, and serum Se levels were measured by inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

Compared with the lowest tertile of Se concentration, those with Se levels in the third tertile were associated with the lower risk of oral cancer (OR = 0.228; 95% CI: 0.135, 0.384). After additional adjustment for genetic risk score (GRS, derived from selenoprotein genetic variants), the model demonstrated the superior goodness of fit. When stratified by GRS, the negative correlation of serum Se was more pronounced among those with low risk (i.e., lower GRS). Moreover, there is a multiplicative interaction between serum Se and GRS for the risk of oral cancer (p = .001).

CONCLUSIONS

The present study suggests that serum Se levels may be significantly associated with oral cancer risk, yet the association may be modified by the effects of selenoprotein genetic variants.

Selenium Influences Trace Elements Homeostasis, Cancer Biomarkers in Squamous Cell Carcinoma Patients Administered with Cancerocidal Radiotherapy

In the perspective of selenium as an antioxidant and anti-carcinogen, so far no strong intervention trials with selenium over radiation-treated oral squamous cell carcinoma cases have been conducted, to examine the response of the disease and the subsequent biochemical alterations. In the present study, untreated oral cancer cases (Gp II) were compared with radiation-treated groups with and without selenium (Gp IIa, IIb), forward to find the trace elements and cancer biomarkers status, at a follow-up of 6 months. Severe alteration in the trace elements levels of Se, Cu, Fe, Zn, Na, K, Ca, Cl, were noticed in Gp II. Though Gp IIa showed slight improvement, administration of selenium (Gp IIb) improved the level of all these elements to a greater extent (p<0.001). GpII and IIa showed increased level of bio markers 5’-nucleotidase, PschE, LAP, γ-GTP, LDH, SGOT, SGPT, ACP, ALP, CPK, TNF, CEA, AFP, Scc-Ag. The greater extent of restitution to near normalcy was observed in patients given selenium (Gp IIb) (p<0.001). Owing to the fact that selenium scavengers oxidants and hence decelerate carcinogenesis by eliminating tumors, so the tumor released constituents into the systemic circulation declined significantly. Therefore, the outcome of the study suggests selenium as a valuable therapeutic measure as adjuvant for oral cancer patients undergoing cancerocidal radiotherapy.

The Epidemiology of Selenium and Human Cancer

The relation between the trace element selenium and the etiology of cancer in humans remains elusive and intriguing, despite the number of epidemiologic studies published on the topic. We address some methodologic issues, such as misclassification of exposure, particularly to single selenium compounds, effect modification, confounding, and other sources of bias, which may explain the inconsistencies in the literature. We also review the results of cohort studies, which have yielded either inverse or null or direct associations between selenium exposure and subsequent cancer risk. To date, no beneficial effect on cancer incidence at major sites, including prostate cancer, has emerged from the Finnish program begun in 1984 to increase the average selenium intake in its population. Populations exposed to unusually high or low levels of environmental selenium might offer unique opportunities to investigate if selenium exposure is related to the etiology of human cancer.

Serum selenium levels and the risk of progression of laryngeal cancer

Background

Observational studies have reported an inverse relationship between selenium status (blood or toenail) and the risk of laryngeal cancer; however, the impact of low serum selenium level on survival has not been evaluated.

Methods

We conducted a prospective study of 296 patients diagnosed with laryngeal cancer in Szczecin, Poland. Serum selenium was measured at diagnosis and prior to treatment. Patients were followed from the date of diagnosis to death at five years. Vital status was obtained by linkage to the Polish National Death Registry.

Results

The five-year survival after diagnosis was 82.0% (95% CI: 68% to 91%) for individuals in the highest quartile of serum selenium (> 66.8 μg/L) and was 28.6% (95% CI 19% to 42%) for individuals in the lowest quartile (<50.0 μg/L). In an age- and sex-adjusted analysis, the hazard ratio (HR) for death from all causes was 7.01 (95% CI 3.81 to 12.9) for patients in the lowest quartile of serum selenium, compared to those in the highest quartile. The corresponding multivariate HR was 3.07 (95% CI 1.59 to 5.94).

Conclusions

This study suggests that a selenium level in excess of 70 μg/L is associated with improved outcome among patients undergoing treatment for laryngeal cancer. Further studies are needed to evaluate if selenium supplementation to achieve this level might improve overall prognosis.

Nail DNA and possible biomarkers: a pilot study

OBJECTIVES

Nail has been a substitute DNA source for genotyping. To investigate the integrity and consistency of nail DNA amplification for biomarker study, nail clippings from 12 subjects were collected at monthly intervals. The possibility of longer amplification and existence of GAPDH RNA/protein, were also investigated with three nail samples.

METHODS

Three primer sets were designed for quantitative amplification of nuclear and mitochondrial genes and analysis of their consistency. The mean threshold cycles in amplification of the target genes were compared to test the consistency of polymerase chain reaction (PCR) performance among individual factors including age groups, sex, family, the nail source, and by the size of the amplification segments.

RESULTS

The amplification of the target genes from nail DNA showed similar integrity and consistency between the nail sources, and among the serial collections. However, nail DNA from those in their forties showed earlier threshold cycles in amplification than those in their teens or seventies. Mitochondrial DNA (mtDNA) showed better DNA integrity and consistency in amplification of all three targets than did nuclear DNA (nucDNA). Over 9 kb of mtDNA was successfully amplified, and nested quantitative PCR showed reliable copy numbers (%) between the two loci. Reverse transcription PCR for mRNA and immunoblotting for GAPDH protein successfully reflected their corresponding amounts. Regarding the existence of RNA and protein in nails, more effective extraction and detection methods need to be set up to validate the feasibility in biomarker study.

CONCLUSIONS

Nail DNA might be a feasible intra-individual monitoring biomarker. Considering integrity and consistency in target amplification, mtDNA would be a better target for biomarker research than nucDNA.

Nail biology and nail science

The nail plate is the permanent product of the nail matrix. Its normal appearance and growth depend on the integrity of several components: the surrounding tissues or perionychium and the bony phalanx that are contributing to the nail apparatus or nail unit. The nail is inserted proximally in an invagination practically parallel to the upper surface of the skin and laterally in the lateral nail grooves. This pocket-like invagination has a roof, the proximal nail fold and a floor, the matrix from which the nail is derived. The germinal matrix forms the bulk of the nail plate. The proximal element forms the superficial third of the nail whereas the distal element provides its inferior two-thirds. The ventral surface of the proximal nail fold adheres closely to the nail for a short distance and forms a gradually desquamating tissue, the cuticle, made of the stratum corneum of both the dorsal and the ventral side of the proximal nail fold. The cuticle seals and therefore protects the ungual cul-de-sac. The nail plate is bordered by the proximal nail fold which is continuous with the similarly structured lateral nail fold on each side. The nail bed extends from the lunula to the hyponychium. It presents with parallel longitudinal rete ridges. This area, by contrast to the matrix has a firm attachment to the nail plate and nail avulsion produces a denudation of the nail bed. Colourless, but translucent, the highly vascular connective tissue containing glomus organs transmits a pink colour through the nail. Among its multiple functions, the nail provides counterpressure to the pulp that is essential to the tactile sensation involving the fingers and to the prevention of the hypertrophy of the distal wall tissue, produced after nail loss of the great toe nail.

Infectious and dietary risk factors of oral cancer

In addition to the classic risk factors of oral cancer, namely alcohol and tobacco, other factors both infectious and environmental are thought to be associated with the development of oral malignancy. Infections in the oral cavity may be an important preventable cause of cancer. Poor oral hygiene, periodontal disease, chronic candidiasis, human papilloma virus (HPV) and herpesvirus infections link statistically with cancer but the mechanisms involved are largely unknown. Infections may trigger cell proliferation, inhibit apoptosis, interfere with cellular signaling mechanisms and up-regulate tumor promoters. In addition, several oral micro-organisms metabolize alcohol to carcinogenic acetaldehyde thus explaining the association between poor oral hygiene, alcohol consumption and carcinogenesis. With regards to dietary factors the Mediterranean-type fruit and vegetable rich diet has been shown to reduce the risk of oral cancer but the evidence is weak, the effect of individual food components and trace elements on carcinogenesis remains unclear at present.

Validity of human nails as a biomarker of arsenic and selenium exposure: A review

Human nail clippings have been used in recent epidemiological studies as a routine bioindicator of arsenic and selenium exposure. To ensure sound application of this biomarker, however, it is important to consider properties and scientific knowledge pertaining to validation of this particular tool. In this review, the use of human nails to measure exposure to arsenic and selenium is discussed in the context of the biomarker validation framework. Literature related to both analytical procedures and intrinsic characteristics of the biomarker is reviewed. Specifically, the followings are addressed: sample collection and preparation methods, establishment of the exposure-biomarker relationship, intraindividual variability and reproducibility of measurements, and biomarker-disease investigations. Drawing from a rapidly growing body of literature, current knowledge of these biomarker validation steps is assessed. Therefore, this review brings attention to the important issue of biomarker validation, laying the framework for future studies measuring elemental composition of nails.

Abnormal DNA repair in selenium-treated human cells

Selenium (Se), a micronutrient and an environmental, a chemical and an industrial agent in many products, can have genotoxic effects as well as antimutagenic and/or anticarcinogenic properties, depending on its concentration and oxidation state. We investigated the cytotoxic response of human osteosarcoma (U2OS) cells to low doses of sodium selenite and assayed their resistivity to cisplatin treatment and their capacity to reactivate cisplatin-treated reporter system, whose repair occurs through the transcription coupled repair (TCR) pathway, using the Host Cell Reactivation (HCR) Assay. In addition, we examined the ability of Se-treated human primary lymphocytes for normal double-strand breaks rejoining (DSBR) using the Challenge assay. Although, U2OS cells did not demonstrate cytotoxicity to all Se doses used, as measured by the cell proliferation MTT assay, their resistivity to cisplatin was significantly reduced. Moreover, Se-treated cells exhibited a significant reduction in their capacity for TCR as compared with untreated control cells. Primary human blood lymphocytes demonstrated cytotoxicity to Se treatment at only a concentration of 10 microM. There were no significant increases in chromosome-type deletions or chromatid breaks or in mitotic indices in cells treated with Se alone or Se plus ionizing irradiation. However, dicentric chromosomes significantly increased upon treatment with 1 microM Se plus irradiation as compared with Se-untreated irradiated control. These findings demonstrate direct evidence on the inhibitory effect of inorganic Se on cellular DNA repair capacity.

Arsenic and other elements in hair, nails, and skin-scales of arsenic victims in West Bengal, India

For the first time, biological tissues (hair, nails, and skin-scales) of arsenic victims from an arsenic affected area of West Bengal (WB), India were analyzed for trace elements. Analysis was carried out by inductively coupled plasma-mass spectrometry (ICP-MS) for 10 elements (As, Se, Hg, Zn, Pb, Ni, Cd, Mn, Cu, and Fe). A microwave digester was used for digestion of the tissue samples. To validate the method, certified reference materials--human hair (GBW 07601) and bovine muscle (CRM 8414)--were analyzed for all elements. The W test was used to study the normal/log normal distribution for each element in the tissue samples. For hair (n=44) and nails (n=33), all elements show log-normal distribution. For skin-scale samples (n=11), data are not sufficient to provide the information about the trend. Geometric mean, standard error, and range for each element were presented and compared with literature values for other populations. This study reveals the higher levels of toxic elements As, Mn, Pb, and Ni in the tissue samples compared with available values in the literature. The elevated levels of these toxic metals in the tissues may be due to exposure of these elements through drinking water and food. The correlations of Mn and Ni with other essential elements, e.g. Fe, Cu, Zn, suggest that Mn and Ni may substitute for those elements in hair, nails, and skin-scales. However, correlation represents the relation between two elements only and does not take into consideration of the presence of other elements. Principle component analysis was applied to explain the behavior among the elements present in hair and nails. This study reveals that in the arsenic-affected areas of WB, the concentrations of other toxic elements in drinking water and foodstuff should be monitored to evaluate the arsenic poisoning.

Selenium and its relationship to cancer: an update

Selenomethionine (Semet) is the major seleno-compound in cereal grains and enriched yeast whereas Se-methylselenocysteine (SeMCYS) is the major seleno-compound in Se-accumulator plants and some plants of economic importance such as garlic and broccoli exposed to excess Se. Animals can metabolize both Semet and SeMCYS. Epidemiological studies have indicated an inverse relationship between Se intake and the incidence of certain cancers. Blood or plasma levels of Se are usually lower in patients with cancer than those without this disorder, but inconsistent results have been found with toenail-Se values and the incidence of cancer. There have been eight trials with human subjects conducted on the influence of Se on cancer incidence or biomarkers, and except for one, all have shown a positive benefit of Se on cancer reduction or biomarkers of this disorder. This is consistent with about 100 small-animal studies where Se has been shown to reduce the incidence of tumours in most of these trials. Se-enriched yeast is the major form of Se used in trials with human subjects. In the mammary-tumour model, SeMCYS has been shown to be the most effective seleno-compound identified so far in reduction of tumours. Several mechanisms have been proposed on the mechanism whereby Se reduces tumours. Even though SeMCYS was shown to be the most effective seleno-compound in the reduction of mammary tumours, it may not be the most effective seleno-compound for reduction of colon tumours.

Mutagenic activity of 4-nitroquinoline-N-oxide in upper aerodigestive tissue in lacZ mice (MutaMouse) and the effects of 1, 4-phenylenebis(methylene)selenocyanate

4-Nitroquinoline-N-oxide (4-NQO) was administered to lacZ mice at a concentration of 20 microg/ml in drinking water for 2 weeks, and the mutagenic fractions in a number of organs were assayed. The mutant fractions in tongue, esophagus and other pooled oral tissues were, respectively, 117+/-26, 73+/-15, and 48+/-15 mutants/10(5) plaque-forming units (pfu) (ca. 15-40xbackground). 4-NQO was not mutagenic in lung, liver or colon at conditions used here. We had previously demonstrated that the synthetic organoselenium compound, 1,4-phenylenebis(methylene)selenocyanate (p-XSC), an established chemopreventive agent, greatly reduced carcinogenicity in 4-NQO in rat tongue, and we observed here that administration of p-XSC (10 ppm se) in the diet for 6 weeks (2 weeks before, during, and 2 weeks after 4-NQO) resulted in a 33% decrease in mutagenesis in oral tissue, a 17% decrease in esophagus, and a slight increase in tongue. Only the decrease in oral tissue reached statistical significance (p<0.04). The results reported here demonstrate that 4-NQO was extremely mutagenic in lacZ mouse tongue, with lower, but highly significant activities in esophagus and other pooled oral tissues. The high activity of 4-NQO in lacZ mouse tongue is consistent with the organ specificity of 4-NQO in the rat. Inhibition of 4-NQO-induced mutagenesis by p-XSC was observed mainly in pooled oral tissues, other than tongue. Possible reasons for the difference between inhibition of mutagenesis and carcinogenesis in tongue are discussed, as well as advantages and disadvantages of in vivo mutagenesis assays as surrogates for carcinogenicity assays in chemoprevention studies.

Chemopreventive agents: selenium

The element selenium (Se) was recognized only 40 years ago as being essential in the nutrition of animals and humans. It is recognized as being an essential component of a number of enzymes, in which it is present as the amino acid selenocysteine. Se compounds have also been found to inhibit tumorigenesis in a variety of animal models, and recent studies indicate that supplemental Se in human diets may reduce cancer risk. The antitumorigenic activities have been associated with Se intakes that correct nutritionally deficient status in animals, as well as higher intakes that are substantially greater than those associated with maximal expression of the selenocysteine-containing enzymes. Therefore, it is proposed that while some cancer protection, particularly that involving antioxidant protection, involves selenoenzymes, specific Se metabolites, which are produced in significant amounts at relatively high Se intakes, also discharge antitumorigenic functions. According to this two-stage model of the roles of Se in cancer prevention, individuals with nutritionally adequate Se intakes may benefit from Se supplementation. Evidence for chemoprevention by Se and for the apparent mechanisms underlying these effects is reviewed to the end of facilitating the development of the potential of Se compounds as cancer chemopreventive agents.

Diet, nutrients, and gastrointestinal cancer

Tobacco and alcohol use are strong risk factors for cancer of the upper gastrointestinal tract. Saturated fat and red meat intake also appear to increase the risk of colorectal cancer. The strongest and most consistent dietary protective factors for gastrointestinal cancer are vegetables and fruits. Some micronutrients show beneficial effects, but the degree of protection is less than that observed from whole plant foods. Substantial decreases in the morbidity and mortality from gastrointestinal cancer could occur with more widespread adoption of dietary guidelines designed for cancer prevention.

Zinc deficiency in head and neck cancer patients

BACKGROUND

Although a great deal of attention has been given to protein and calorie malnutrition in patients with head and neck cancer, zinc status has not been assessed properly in such patients in the past.

METHODS

In this study we characterized zinc status by cellular zinc criteria and assessed several measures of protein and calorie malnutrition in patients with head and neck cancer. We determined prognostic nutritional index (PNI) based on serum albumin, serum transferrin, triceps skin fold measures, and delayed hypersensitivity, as proposed by Buzby et al. In this study, the baseline zinc status and PNI of 60 head and neck cancer patients were correlated with the tumor size and overall stage of the disease.

RESULTS

Our results showed that the tumor size and overall stage correlated significantly to zinc status whereas no correlation was seen with PNI, alcohol intake, or smoking in our study subjects.

CONCLUSION

We conclude that zinc status is a better indicator of tumor burden and stage of the disease in head and neck cancer patients than the patients' overall nutritional status.

Work in dry cleaning and the incidence of cancer of the oral cavity, larynx, and oesophagus

OBJECTIVES

To investigate whether employment in dry cleaning, and potential exposure to perchloroethylene (PCE), were associated with increased risk of carcinoma of the oral cavity and pharynx, larynx, oesophagus, and gastric cardia.

METHODS

Two population based case-control studies were carried out. There were 491 cases of carcinoma of the oral cavity and pharynx, 235 of the larynx, and 404 of the oesophagus and gastric cardia. 724 controls were selected by random digit dialing. Personal interviews ascertained information on lifetime job histories, cigarette use, alcohol consumption, and other potential risk factors. The probability and level of exposure to PCE were estimated from the scientific literature.

RESULTS

People who worked in dry cleaning tended to consume less alcohol and cigarettes than the general population. The adjusted odds ratio (OR) associated with ever having worked in dry cleaning was 1.6 (95% confidence interval (95% CI) = 0.6 to 4.4) for all cancer types together. The strongest associations were with laryngeal (OR 2.7; 95% CI 0.6 to 10.9) and oesophageal squamous cell carcinomas (OR 3.6; 95% CI 0.5 to 27.0). For laryngeal cancer, the relative risk increased with number of years employed in the dry cleaning industry (P = 0.14. The two cases of oesophageal squamous cell carcinomas had worked in dry cleaning for only a short time. Analyses of subsites showed higher risks for supraglottic laryngeal cancer (OR 5.7; 95% CI 1.0 to 32.1) and cancer of the tongue (OR 2.3; 95% CI 0.4 to 12.6). Analyses of exposure to PCE yielded similar results.

CONCLUSIONS

These findings could easily be explained by chance; nevertheless, they are consistent with previous reports of excess risk of oesophageal, laryngeal, and tongue cancer, and suggest that previous studies of dry cleaners that could not control for alcohol and cigarette use may have underestimated the relative risks of such cancers.

Biological staging of head and neck cancer and its role in developing effective treatment strategies

The purpose of a cancer staging system is to encompass all attributes of a tumor that define its life history. We propose a biological staging system which incorporates all of the phases of the natural history of head and neck cancer beginning with the earliest cellular changes extending through the early phase of invasion to the occurrence of metastasis and, finally, culminating in therapeutically refractory disease. This temporally structured system recognizes the importance of constitutional predisposition, and the impact of environmental factors. The intent is to augment the AJCC/UICC staging system and use this system to provide a framework which will easily incorporate current and future advances in basic science, prevention, therapy and palliation which will improve the quality and quantity of life for patients.

Nutrition and oral cancer

Epidemiologic evidence on the relationship between nutrition and oral cancer is reviewed. Ecologic and case-control studies provide most of the evidence regarding the nutritional epidemiology of oral cancer. The ecologic evidence is that the considerable geographic variation in the incidence of oral cancer is consistent with variation in nutrition. Because incipient oral cancer is likely to affect the diets of oral cancer patients, even before diagnosis, case-control studies are limited by their ability to extract comparable information from subjects regarding their pre-illness diets. The case-control evidence is that a diet that emphasizes fruit and vegetable intake may protect against oral cancer. However, this case-control evidence is not highly consistent; individual foods that appear protective in some studies do not in others, and the effects of diet appear to be modest when compared with those of smoking and alcohol consumption. The nutritional epidemiology of oral cancer is marked by two risk factors that appear far more powerful than nutrition: tobacco use and alcohol consumption. As these likely are related to nutrition, they pose as important potential confounders. Oral hygiene also may confound the association of nutrition and oral cancer risk; it is likely to be associated with dietary practice, and it has been shown to be related to oral cancer risk. Thus, studies of nutrition in the epidemiology of oral cancer also must address the effects of tobacco and alcohol consumption and oral hygiene.

A case study of nutrient intervention of oral precancerous lesions in India

Tobacco chewing and/or smoking are strongly related to several cancers, mainly of the upper aerodigestive tract. Several studies on diet and cancer links suggest that micronutrients, particularly antioxidant vitamins and minerals, are risk modifiers of cancers of epithelial origin. This study looks at the impact of micronutrients such as vitamin A, riboflavin, zinc and selenium as intervention agents in subjects with and without precancerous lesions in a high risk group (reverse smokers of chutta-rolled tobacco leaf). Reverse smokers from four villages were enrolled in the study. 150 subjects were supplemented with four nutrients, namely vitamin A, riboflavin, zinc and selenium in the form of a capsule twice a week for 1 year. 148 controls received a placebo capsule containing lactose for the same period. Clinical history and anthropometric data were collected from all the subjects and a clinical photograph of the palate was taken. Micronutrients were estimated in random blood collected from a sub-sample before and after the study. Micronutrients improved the vitamin A, riboflavin and selenium nutriture in the supplemented group with a concomittant regression of precancerous lesions present on the palate. Clinically complete remission of white, red and combination lesions was seen in 57% of subjects on supplements whereas 8% on placebo showed a positive response. Further progression of these lesions was seen in 10% of the supplemented group compared with 47% in the placebo group (P < 0.001). In the non-lesion group, new lesions appeared in 12% on supplements while more than 38% on the placebo developed new lesions (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism and cancer of the larynx: a case-control study in western Washington (United States)

Alcohol consumption is a well-known risk factor for laryngeal cancer. To determine whether alcoholism, as measured by responses to the Michigan alcoholism screening test (MAST), is a risk factor for laryngeal cancer independent of alcohol consumption, we analyzed data from a population-based case-control study. Personal interviews were conducted with 235 patients (81 percent response rate) with laryngeal cancer diagnosed from September 1983 through February 1987, who were residents of the Seattle metropolitan area. A total of 547 controls frequency-matched by age and gender, selected by random-digit dialing, were interviewed (75 percent response rate). When considered in a multivariate model, independent risk factors for laryngeal cancer included: alcohol consumption (42 or more drinks/wk compared with seven or less drinks/wk: odds ratio [OR] = 3.1, 95 percent confidence interval [CI] = 1.2-7.9); cigarette use (40 or more cigarettes/day compared with never-smoked: OR = 23.1, CI = 9.4-52.6); and weighted positive responses to the MAST (score of five or more compared with score of zero: OR = 1.9, CI = 1.1-3.4). Possible explanations for the association between alcoholism and laryngeal cancer are that a measure of alcoholism improves the accuracy of assessment of alcohol consumption, that alcoholism is associated with a pattern of alcohol consumption that increases the risk of laryngeal cancer, or that alcoholism may be a marker for host susceptibility to the carcinogenic effects of alcohol.

Fingernail creatinine as a predictor of prior renal function

When a patient presents with renal failure, it is often difficult to ascertain whether the individual is suffering from acute or chronic renal failure. Fingernail creatinine might help to differentiate between the two. To test this possibility, the relationship between the fingernail creatinine and the serum creatinine obtained concurrently or 1 or more months previously was examined in 22 normal adults, nine patients with acute renal failure, seven patients with chronic renal failure not undergoing dialysis, 16 maintenance hemodialysis patients, and 33 patients with a functioning renal transplant who had been transplanted 0.2 to 3.9 months (n = 21) or 4.3 to 33 months previously (n = 12). Fingernail creatinine was significantly greater than normal in the patients with chronic renal failure, patients undergoing maintenance hemodialysis, and patients who had a functioning renal transplant implanted 0.2 to 3.9 months previously. In contrast, fingernail creatinine was not different from normal in the patients with acute renal failure and in patients who had a functioning renal transplant placed 4.3 to 33 months previously. In the maintenance hemodialysis patients, fingernail creatinine showed the strongest correlation with the serum creatinine obtained between 5 and 10 months previously, with the highest correlation at 9 months. In the renal transplant recipients, the fingernail creatinine decreased to normal or near normal values within approximately 90 to 120 days after transplantation. These findings indicate that fingernail creatinine may reflect the serum creatinine values several months previously. The fingernail creatinine may help to identify whether patients have recent onset as compared with longstanding renal failure.