Urinary Neopterin Levels Research Articles

Serum neopterin level in psoriatic patients treated with acitretin or narrowband ultraviolet B or both

Background A biological indicator of cellular immunity is neopterin. In certain studies, psoriasis patients had higher serum, and urine neopterin levels, which were reduced following therapy. Aims To evaluate the effect of acitretin versus narrowband ultraviolet B (NB-UVB) and combinations of them on psoriasis vulgaris and correlate it with neopterin level Patients and methods In this case-control research, a total of 120 respondents (30 healthy volunteers) served as the control group, in addition to 90 psoriasis patients randomly allocated into three equal groups: group (I): 30 patients received Acitretin for 3 months. Group (II): 30 patients were treated with NB-UVB. Group (III): 30 patients received Acitretin and NB-UVB (3 sessions/week) for 3 months. Serum neopterin levels were measured pre- and post-treatment. All patients were clinically and photographically evaluated using the Psoriasis Area and Severity Index (PASI) score. The study was registered at clinicaltrial.com. Approval numbers: NCT05401006 and date of registration: 1/6/2022. Results In this study, statistically significant higher serum neopterin levels have been found in psoriatic patients than healthy controls. We found a significant decrease in PASI scores in all groups. The relative reduction percentage in the PASI score was substantially different between groups (P<0.001). The highest decrease percentage in PASI score was reported in group III compared with group II (NB-UVB) and group I (Acitretin group), (P<0.001). The median s. neopterin levels after treatment varied substantially among the three groups (P<0.001). Conclusion When compared with healthy controls, serum neopterin levels in psoriatic patients were substantially greater (P<0.05).

Emotional states predict cellular immune system activity under conditions of life as it is lived: A multivariate time-series analysis approach.

The relationship between emotional states and immune system activity is characterized by bidirectional influences; however, limited information is available regarding the temporal dynamics of these effects. The goal of this investigation was to examine how these psychoimmunological interdependencies unfold over time under conditions of "life as it is lived". For this purpose, three healthy women collected their entire urine over a period of approximately two months at 12-h intervals (8 am-8 pm, 8 pm-8 am), resulting in a total of 112 to 126 consecutive measurements per subject. In addition, among other regular psychological assessments, the subjects completed the EWL-60-S, an emotional state questionnaire, each morning and evening. To assess the extent of T-helper type 1 immune activation, the neopterin per creatinine concentration was measured in the urine samples using high-pressure liquid chromatography. The dynamic relationships between the time series of the six emotional states (performance-related activity, general inactivity, extraversion/introversion, general feeling of comfort, emotional irritation, anxiety/depressiveness) and urinary neopterin levels were estimated in vector-autoregressive models and evaluated using Granger-causality tests, impulse-response functions and forecast error variance decompositions. The findings showed that emotional states explained up to 20% of the variance of urinary neopterin per creatinine levels, whereby most of the effects occurred within a period of approximately three days. Across all subjects, increases in anxiety/depressiveness and extraversion led to increases in neopterin levels, while a general feeling of comfort led to decreases in neopterin. These results emphasize the importance of the interdependencies between emotional states and immune system activity and showcase the potential that intensive longitudinal study designs offer for psychoneuroimmunology.

Urinary neopterin and biopterin indicate that inflammation has a role in autism spectrum disorder.

Inflammation is thought to be involved in the pathogenesis of autism spectrum disorder (ASD). Pteridine metabolites are biomarkers of inflammation that increase on immune system activation. In this study, we investigated the urinary pteridine metabolites in ASD patients as a possible biomarker for immune activation and inflammation. This observational, cross-sectional, prospective study collected urine samples from 212 patients with ASD and 68 age- and sex-matched healthy individuals. Urine neopterin (NE) and biopterin (BIO) levels were measured. Patients who had chronic disorders, active infection at the time of sampling, or high C-reactive protein levels were excluded. The urine NE and BIO concentrations were determined by high-performance liquid chromatography. The ratios of both NE and BIO to creatinine (CRE) were used to standardise the measurements. The NE/CRE and NE/BIO levels were significantly higher in ASD patients than controls. Univariate and multivariate models revealed a significant increase in NE/CRE and NE/BIO in ASD patients. There was a significant relationship between the NE/BIO [average area under the curve (AUC) = 0.717; range: 0.637-0.797] and NE/CRE (average AUC = 0.756; range: 0.684-0.828) ratios, which distinguished individuals with ASD from controls. The elevated NE/CRE and NE/BIO ratios suggest that inflammation and T cell-mediated immunity are involved in the pathophysiology of autism. NE/BIO could serve as a diagnostic inflammatory marker in the pathogenesis of ASD.

Effect of NB-UVB therapy on IL-6 and neopterin levels in patients with psoriasis

Abstract Background Psoriasis is a chronic and non-transient disease with increased epidermal proliferation in the skin. Dysregulation of the immune system is an important factor in this pathology. Inflammation markers, pro-inflammatory cytokines, and immune cells are reported to be changed in psoriasis. Study design In the current cohort study, the possible changes in interleukin-6 (IL-6), neopterin levels, and kynurenine (Kyn) pathway in 42 psoriasis patients compared to 30 controls, and their change with narrow-band (NB) UVB treatment were investigated. Methodology IL-6 and serum neopterin levels were analyzed with ELISA kits. HPLC analyses were performed to detect urinary neopterin, serum Kyn, and tryptophan (Trp) levels. Results IL-6 levels were lower, while Kyn levels and the Kyn-to-Trp ratio were higher in psoriasis patients compared to control subjects (p < 0.01, all). Conclusion Narrow-band ultraviolet B (NB-UVB) treatment decreased Psoriasis Area and Severity Index (PASI) scores and increased urinary neopterin levels of the patients (both, p < 0.01). Serum neopterin was correlated with Kyn and Kyn/Trp levels before and after NB-UVB treatment (p < 0.05, all). These findings point out that the measured parameters might be considered to support the PASI score in both diagnosis and prognosis of psoriasis rather than evaluating the severity of the disease.

Neopterin Levels in Bonobos Vary Seasonally and Reflect Symptomatic Respiratory Infections

As environmental changes exacerbate the threat coming from infectious diseases in wild mammal species, monitoring their health and gaining a better understanding of the immune functioning at the species level have become critically important. Neopterin is a biomarker of cell-mediated immune responses to intracellular infections. We investigated the variation of urinary neopterin (uNeo) levels of wild, habituated bonobos (Pan paniscus) in relation to individual and environmental factors. We used 309 urine samples collected between 2010 and 2018 at the LuiKotale field site, DRC. Based on current knowledge on zoo-housed conspecifics and closely related species, we predicted uNeo levels to increase (1) during infections, (2) with increasing age, (3) over the gestation period and in estrous females; and (4) to vary seasonally. Our results showed uNeo levels varied over a one-year period and increased in individuals showing respiratory symptoms. Contrary to chimpanzees, uNeo levels did not vary with age or female reproductive status, possibly due to our small sample size. Our study provides a baseline for a better understanding of bonobo’s immunocompetence in the context of socio-ecological pressures and for monitoring the health of wild populations.

Determination of neopterin in urine of industrial workers by HPLC.

This study aimed to determine neopterin levels in the urine of industrial workers by the high-performance liquid chromatography method. Intra- and inter-day precision values for neopterin in urine were less than 3.14, and accuracy (relative error) was better than 3.00%. The limits of detection and quantification of neopterin were 0.3 and 1.0 ng/mL, respectively. Also, the developed method was applied to real samples to determine the neopterin levels in the urines of industrial workers, who have been exposed to various chemicals such as formaldehyde, heavy metals and thinners. Urine neopterin levels of industrial workers including auto painters, bodywork and furniture workers were statistically compared with healthy volunteers. The highest and lowest values of urinary neopterin for industrial workers were obtained 908.96 and 119.86 μmol/mol, respectively. Our investigation demonstrates that there is a meaningful difference in urinary neopterin levels between the workers and the control groups (P<0.05). Workers in the auto paint, body and furniture business may have been exposed to a toxic environmental exposure in their occupation. As a result, an increase in the concentration of neopterin in the urine may be important in the diagnosis and treatment of various diseases.

Urinary neopterin and total neopterin measurements allow monitoring of oxidative stress and inflammation levels of knee and hip arthroplasty patients.

Knee and hip arthroplasty are common surgeries within an aging population. Some data has suggested that knee arthroplasty is more traumatic to the body than hip arthroplasty due to the increased complexity and load bearing nature of the joint. Here, we compare the stress of the two surgeries by measuring urinary neopterin and total neopterin as biomarkers of oxidative stress and inflammation. Urinary neopterin and total neopterin (neopterin + 7,8-dihydroneopterin) levels were analysed in 28 knee and 22 hip arthroplasty patients pre- and post-operatively to determine oxidative stress and inflammation levels. Total neopterin was 31.1% higher with knee arthroplasty (p<0.05). Urinary neopterin was 32.8% higher in the knee arthroplasty group versus hips. The increase in neopterin and total neopterin following a post-surgical decrease in levels was significant in both groups. Levels of neopterin and total neopterin were varied between patients, but all increased following surgery and subsided by day 28. The increased levels of urinary neopterin and total neopterin from knee arthroplasty indicate that knee osteoarthritis and arthroplasty is a more significant trauma to the body than hip osteoarthritis and arthroplasty surgery. This is also shown by faster inflammatory resolution following hip arthroplasty.

Occupational exposure to crystalline silica and peripheral biomarkers: An update.

Peripheral biomarkers are important tools for detecting occupational exposures to prevent the onset and/or progression of diseases. Studies that reveal early peripheral biomarkers are highly important to preserve the health of workers and can potentially contribute to diagnosing and/or prognosing occupational pathologies. Exposure to crystalline silica is a problem in several workplaces because it increases the risk of chronic obstructive pulmonary disease (COPD), tuberculosis, cancer, and pulmonary fibrosis, clinically defined as silicosis. Silicosis is diagnosed by chest radiography and/or lung tomography in advanced stages when there is a severe loss of lung function. Peripheral biomarkers can help in diagnosing early changes prior to silicosis and represent a highly important technical-scientific advance that is minimally invasive. This review aimed to investigate the biomarkers studied for evaluating occupational exposure to crystalline silica and to understand the recent advances in this area. Potential oxidative, inflammatory, and immunological biomarkers were reviewed, as well as routine biomarkers such as biochemical parameters. It was found that biomarkers of effect such as serum CC16 and l-selectin levels could represent promising alternatives. Additionally, studies have shown that neopterin levels in urine and serum can be used to monitor worker exposure. However, further studies are needed that include a greater number of participants, different times of exposure to crystalline silica, and a combination of silicosis patients and healthy volunteers. Evaluating the concentration of crystalline silica in occupational environments, its impact on biomarkers of effect, and alterations in lung function could contribute to revealing early health alterations in workers in a more robust manner.

Cell-Mediated Immune Ontogeny Is Affected by Sex but Not Environmental Context in a Long-Lived Primate Species

Ecoimmunology conceptualizes the role of immunity in shaping life history in a natural context. Within ecoimmunology, macroimmunology is a framework that explains the effects of habitat and spatial differences on variation in immune phenotypes across populations. Within these frameworks, immune ontogeny—the development of the immune system across an individual life span—has received little attention. Here, we investigated how immune ontogeny from birth until adulthood is affected by age, sex, and developmental environment in a long-lived primate species, the bonobo. We found a progressive, significant decline of urinary neopterin levels, a marker for the cell-mediated immune response, from birth until 5 years of age in both sexes. The overall pattern of age-related neopterin changes was sex-specific, with males having higher urinary neopterin levels than females in the first 3 years of life, and females having higher levels than males between 6 and 8 years. Environmental condition (zoo-housed vs. wild) did not influence neopterin levels, nor did age-related changes in neopterin levels differ between environments. Our data suggest that the post-natal development of cell-mediated immune ontogeny is sex-specific but does not show plasticity in response to environmental conditions in this long-lived primate species. This indicates that cell-mediated immune ontogeny in the bonobo follows a stereotypic and maybe a genetically determined pattern that is not affected by environmental differences in pathogen exposure and energy availability, but that sex is an important, yet often overlooked factor shaping patterns of immune ontogeny. Investigating the causes and consequences of variation in immunity throughout life is critical for our understanding of life-history evolution and strategies, mechanisms of sexual selection, and population dynamics with respect to pathogen susceptibility. A general description of sex-specific immune ontogeny as done here is a crucial step in this direction, particularly when it is considered in the context of a species’ ecology and evolutionary history.

Neopterin and biopterin levels and tryptophan degradation in patients with diabetes

This study aimed to evaluate the possible changes of neopterin, biopterin levels and tryptophan degradation in diabetes and to compare the results within diabetes groups and with healthy subjects. Diabetes mellitus patients and healthy controls were recruited the study. Patients were further subgrouped according to their drug therapy. Serum neopterin concentrations were detected by ELISA. Urinary neopterin, biopterin, serum tryptophan (Trp) and kynurenine (Kyn) levels were detected by HPLC. There was no difference between controls and diabetes patients in serum neopterin, urinary neopterin and biopterin levels (p > 0.05, all). Serum Trp and Kyn levels were significantly different in type 1 diabetes (T1DM) patients compared to controls (p < 0.05, both). Serum neopterin levels were significantly higher in type 2 diabetes patients (T2DM) compared to T1DM (p < 0.05). Urinary biopterin levels of T2DM patients using both metformin and vildagliptin were significantly higher than T1DM patients (p < 0.05). The correlations between serum neopterin and urinary neopterin, Kyn and Kyn/Trp were statistically significant in control and patient groups (p < 0.05, all). The study showed that Kyn/Trp was altered in diabetes patients due to immune modulation. On the other hand, although xenobiotic exposure may change pteridine levels, metformin and/or vildagliptin use in T2DM patients did not have any effect on the measured parameters.

Urinary Cortisol Increases During a Respiratory Outbreak in Wild Chimpanzees.

: In mammals, the excretion of cortisol can provide energy toward restoring homeostasis and is a major component of the stress response. However, chronically elevated cortisol levels also have suppressive effects on immune function. As mounting an immune response is energetically costly, sick individuals may conserve energy by exhibiting certain sickness behaviors, such as declining activity levels. Due to the complex interplay between immune function and sickness behaviors, endocrinological correlates have received growing attention in the medical community, but so far, this subject was investigated rarely. Furthermore, given the complexities of studying illnesses and immunity in natural settings, correlates of sickness behaviors have yet to be studied in non-human primates in the wild.Methods: We measured urinary cortisol levels using liquid chromatography–mass spectrometry in a group of wild habituated chimpanzees in Taï National Park, Côte d'Ivoire, before, during, and after a respiratory disease outbreak (main causative pathogen: human respiratory syncytial virus A, with coinfections of Streptococcus pneumoniae). Changes in cortisol levels were then related to urinary neopterin levels, a biomarker of immune system activation.Results: Urinary cortisol levels were found to be more than 10-fold higher during the outbreak in comparison with levels before and after the outbreak period. Increasing cortisol levels were also associated with increasing neopterin levels. Interestingly, rather atypical patterns in a diurnal decline of cortisol levels were found during infection periods, such that levels remained raised throughout the day.Conclusion: In conclusion, cortisol increase was related to cellular immune response. Our results suggest that cortisol is a mediator of infectious disease pathogenicity through its impact on the immune system and that wild chimpanzees may be facing energetic stress when sick. By monitoring immune challenges in wild-living animals, our study demonstrates that immune defenses have costs and that these costs are context-specific.

Elevated neopterin levels in wild, healthy chimpanzees indicate constant investment in unspecific immune system

BackgroundEcological immunology proposes that the optimal immune defence, and the costs coming with it, vary across environments. In environments with higher pathogen load, the immune system should experience greater challenges and, therefore, investment in maintaining it should be higher. The biomarker neopterin allows monitoring of innate immune responses, and is therefore an ideal tool to investigate the effects of ecological variables on the immune system. Here, we compared urinary neopterin levels of apparently healthy chimpanzees without acute symptoms of sickness across two environments: in captivity (22 zoos) and in the wild (two populations).ResultsOur results revealed that urinary neopterin levels were nearly twice as high in wild compared to captive chimpanzees, independent of chimpanzee subspecies.ConclusionWe conclude that wild chimpanzees experience more frequent immune challenges in comparison to captive individuals. Therefore, wild individuals have to allocate more energy to immune function and away from reproduction and growth. Our data indicate that the generally delayed development of wild animals in comparison to captive individuals might not only be related to lower energy intake but might result from greater energy allocations to immune function. Finally, our data highlight the importance of understanding immune costs for accurate characterization of energy budgets in animals.

Moderate running exercise prevents excessive immune system activation

Benefits of exercise have been documented for many diseases with a chronic progression, including obesity, diabetes mellitus, cardiovascular diseases, neurodegenerative diseases, certain types of cancers, and overall mortality. Low-grade systemic inflammation is a key component of these pathologies and it has been demonstrated that can be prevented by performing regularly physical exercise. The aim of this study was to examine the effect of lipopolysaccharide (LPS)-induced inflammation on glucose and insulin tolerance, exercise performance, production of urinary neopterin and striatal neurotransmitters levels in adult male C57BL/6 mice. Increased blood glucose clearance and insulin sensitivity were observed after a single administration of glucose (2 g/kg, p.o.) or insulin (0.5 U/kg, i.p.). However, the repeated injection of LPS (0.33 mg/kg/day, i.p.) decreased glucose tolerance and increase urinary neopterin levels, pointing to systemic inflammation. In parallel to the urinary-increased neopterin, it was observed a significant reduction in the striatal dopamine levels and an increase in the serotonin/dopamine ratio. While a single LPS injection (0.33 mg/kg, i.p.) showed impaired performance in the incremental loading test (10 m/min, with 2 m/min increment every 3 min, at 9% grade), a moderate physical exercise protocol (treadmill for three weeks; 5 sessions/week; up to 50 min/day) prevented the exacerbation of immune system activation and preserved mitochondrial activity in skeletal muscle from mice with continuous LPS infusion (infusion pumps: 0.83 mg/kg/day, i.p.). In conclusion, the peripheral-induced inflammation elicited metabolic alterations that provoked impairment in striatal dopamine metabolism. The moderate exercise prevented the increase of urinary neopterin and preserved mitochondrial activity under LPS-induced inflammatory conditions.

Evaluation of Neopterin Level and Disease Severity in Patients with Psoriasis Vulgaris Treated with Narrowband UVB.

Background:Neopterin is a biochemical marker of cellular immunity. It has been reported that serum and urine neopterin levels increase in psoriasis and decrease with treatment. Nevertheless, assessment of a direct link between narrowband ultraviolet B (UVB) therapy and neopterin level in association with Psoriasis Area and Severity Index (PASI) scores has not been performed yet. We aimed to evaluate the serum neopterin level in patients with psoriasis treated with narrowband UVB therapy in association with disease severity.Materials and Methods:The study included 35 patients with chronic plaque-type psoriasis who had PASI scores of >10 or below 10 but resistant to topical therapies and 30 healthy individuals. The narrowband UVB therapy was administered to the patient group (n = 35). Serum neopterin analysis was performed with an enzyme-linked immunosorbent assay method before and after treatment.Results:There was statistically significant correlation between neopterin level and PASI score in the patient group (P = 0.011). The serum neopterin level was significantly increased in patients with higher PASI score. Moreover, the serum neopterin level was found to be statistically higher in severe psoriasis group (PASI score ≥10, n = 14) than the mild-moderate group (PASI score <10, n = 21) (P = 0.001). Furthermore, a significant decrease was observed according to serum neopterin level after the narrowband UVB therapy in the remaining 20 patients who were able to comply with the scheduled therapy and follow-up procedure (P = 0.026).Conclusion:Serum neopterin levels were found to be an useful marker for evaluating disease severity and efficacy of narrowband UVB treatment. Thus, our findings may provide a new approach with the management of disease and follow-up strategies in patients with psoriasis.

Urinary neopterin levels increase and predict survival during a respiratory outbreak in wild chimpanzees (Ta\xef National Park, C\xf4te d\u2019Ivoire)

Monitoring immune system activation of wild animals has garnered increasing interest within the field of ecological immunology, leading to an urgent need for non-invasive biomarkers measuring these changes. Urinary neopterin, a marker of the cell-mediated immune response, is validated as an immune-related biomarker in captive and laboratory animals. However, wild animals naturally host higher and chronic pathogen loads. Therefore, detection and quantification of additional infections via neopterin might not be possible against the background of a chronically challenged immune system. To assess the suitability of urinary neopterin in wild animals, we measured neopterin corrected for specific gravity with an enzyme immunoassay in 185 samples collected before, during and after a respiratory disease outbreak in 28 individuals from a group of wild chimpanzees (Taï National Park, Côte d’Ivoire). Urinary neopterin levels were significantly higher during periods when individuals showed respiratory symptoms versus before and after the outbreak. Furthermore, urinary neopterin levels were significantly higher in individuals that died, with higher levels already apparent before the outbreak, suggesting individuals may have an already activated immune system. Measuring urinary neopterin levels, with other biomarkers of energetic condition, stress challenges, and reproduction will contribute towards a deeper understanding of life-history trade-offs in wild animals.

The Use of Neopterin as a Noninvasive Marker in Monitoring Diseases in Wild Chimpanzees

Pathogen analysis in wild great apes is both time- and resource-consuming. Therefore, we examined the potential use of urinary neopterin, a sensitive marker of cell-mediated immune system activation, as a disease marker and unspecific screening tool to facilitate informed pathogen analysis in great ape health monitoring. To test this, urinary neopterin was correlated to other disease markers such as sickness behaviors, fever, and urine parameters. Seasonal variation in urinary neopterin levels was investigated as well. The study encompassed noninvasively collected longitudinal data of young wild chimpanzees from the Taï National Park, Côte d´Ivoire. Relationships between disease markers were examined using a linear mixed model and a case study approach. Seasonal variation in urinary neopterin was tested using a linear mixed model. While the linear mixed model found no obvious relationship between urinary neopterin levels and other disease markers, the case study approach revealed a pattern resembling those found in humans. Urinary neopterin levels indicated seasonal immune system activation peaking in times of low ambient temperatures. We suggest the use of urinary neopterin as an unspecific screening tool in great ape health monitoring to identify relevant samples, individuals, and time periods for selective pathogen analysis and zoonotic risk assessment.

Neopterin, Inflammation, and Oxidative Stress: What Could We Be Missing?

Neopterin has been extensively used as a clinical marker of immune activation during inflammation in a wide range of conditions and stresses. However, the analysis of neopterin alone neglects the cellular reactions that generate it in response to interferon-γ. Neopterin is the oxidation product of 7,8-dihydroneopterin, which is a potent antioxidant generated by interferon-γ-activated macrophages. 7,8-Dihydroneopterin can protect macrophage cells from a range of oxidants through a scavenging reaction that generates either neopterin or dihydroxanthopterin, depending on the oxidant. Therefore, plasma and urinary neopterin levels are dependent on both macrophage activation to generate 7,8-dihydroneopterin and subsequent oxidation to neopterin. This relationship is clearly shown in studies of exercise and impact-induced injury during intense contact sport. Here, we argue that neopterin and total neopterin, which is the combined value of 7,8-dihydroneopterin and neopterin, could provide a more comprehensive analysis of clinical inflammation than neopterin alone.

Urinary neopterin and serum uric acid levels in patients with multiple sclerosis during relapses

Urinary neopterin and serum uric acid levels in patients with multiple sclerosis during relapses

A New Diagnostic and Prognostic Marker in Endometrial Cancer: Neopterin.

In this study, we investigated the correlation between serum and urinary neopterin levels as well as the stage of the disease in women with endometrial cancer.Increased neopterin concentrations are reported in patients with activation of macrophages by interferon-γ, which includes the following: viral infections, autoimmune disorders, allograft rejection, and various malignant tumors. In patients with several types of cancer, high-neopterin concentrations in body fluids like serum/plasma, urine, ascites, and cerebrospinal fluid indicate the course of the disease, and it is associated with poor prognosis. In the light of foregoing, we aimed to investigate the role of neopterin as a prognostic biomarker in endometrial cancer. Serum neopterin concentrations were determined by enzyme-linked immunosorbent assay and urinary neopterin by high-performance liquid chromatography in 41 patients with endometrial cancer (group 2) and 41 healthy women (group 1). Increased urinary neopterin levels were observed in patients with endometrial cancer (P < 0.001), and the difference in the urinary neopterin levels between low and high stages of endometrial cancer was significant (P < 0.01; stage I-II vs stage III-IV, respectively). Serum neopterin levels did not show a significant difference in each group. This study suggests that urinary neopterin levels are relevant in evaluating the endometrial cancer stage and follow-up of the disease. As a result, using neopterin and cancer antigen 125 together would be useful in determining the prognosis of endometrial cancer and its posttreatment progression.

Validation of a Method for the Assessment of Urinary Neopterin Levels to Monitor Health Status in Non-human-primate Species.

Determining individual health status is of great importance for a better understanding of life history trade-offs between growth, reproduction, and maintenance. However, existing immunological methods are invasive and therefore not suitable for investigating health status in wild populations. Thus, there is an urgent need for non-invasive methods to assess the immune status of animals. Neopterin is involved in the cell-mediated pathway of the immune response (Th1–type), secreted during the activation of monocytes and macrophages. We investigated if urinary neopterin could serve as a biomarker of health status in bonobos and chimpanzees. First, we performed a chemical validation of a commercial neopterin enzyme immune assay (EIA) for bonobo and chimpanzee urine. We then examined if urinary neopterin levels in bonobos increase during the acute period of respiratory infections. We found that neopterin levels can be reliably measured in urine of the two species with a commercial EIA. Stability experiments revealed considerable changes in urinary neopterin levels in relation to multiple freeze–thaw cycles and extended exposure to room temperature. Exposure to sunlight led to a degradation of urinary neopterin, whereas sample storage up to 2 years did not affect urinary neopterin levels. There was no detectable diurnal variation in neopterin levels, and levels remained very stable across several days in healthy individuals. While urinary neopterin levels were independent of sex, non-adult individuals had higher urinary neopterin levels than adults. Most importantly, there was a significant increase in urinary neopterin levels during a period of respiratory infection. Our results demonstrate that regular urine sample collection would allow for the monitoring of individual health status and disease progression with minimal disturbance of the subjects. In combination with behavioral, life history, and endocrinological parameters, the method can be used to investigate questions related to immunocompetence handicaps or life history trade-offs.