Urinary neopterin concentrations in patients with Balkan endemic nephropathy (BEN)

Serum Neopterin Levels Among Hepatitis C-Positive Living-Donor Renal Transplant Recipients

BACKGROUND

The role of neopterin as a marker of cell-mediated immunity for immunological monitoring after transplantation is of great potential interest. Neopterin levels among hepatitis C virus (HCV)-positive recipients of living-donor renal transplantation (LDRT) have not been previously described.

METHODS

Twenty-two HCV-positive (group I) and 10 HCV-negative (group II) recipients of LDRT were serially monitored for serum neopterin levels by enzyme-linked immunosorbent assay (ELISA). Group I patients were monitored thrice, ie, before transplantation, day 10, and 6 months post transplantation, while group II patients were monitored twice (day 10 and 6 months post transplantation). Peripheral blood T-lymphocyte subsets (CD3, CD4, CD8, CD4⁺CD25⁺, CD₁₆₊₅₆) and Th1/Th2 cytokines were monitored concomitantly by flow cytometry.

RESULTS

Ten days post transplantation, there was a significant increase in neopterin and neopterin/creatnine levels among group I patients. There was a positive correlation between activated T-lymphocyte (CD4⁺CD25⁺) and neopterin early post transplantation (day 10). Th2 cytokines IL-10 and IL-5 showed a positive correlation with neopterin levels on day 10 and 6 months post transplantation, respectively. Neopterin levels did not show association with either HCV viral load or allograft rejection among our study cohort.

CONCLUSION

Increased monocyte/macrophage activation with elevated serum neopterin was detected among group I patients on day 10 post transplantation, but it could not predict rejection. It appears that IL-10 either from a regulatory or nonregulatory source helps in the maintenance of stable graft early post transplantation. Further, it would be of interest to assess the role of neopterin in chronic allograft nephropathy and long-term graft outcome.

Macrophage activation and coronary atherosclerosis in systemic lupus erythematosus and rheumatoid arthritis

OBJECTIVE

Activation of macrophages may contribute to increased atherosclerosis and coronary artery disease in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Neopterin, a pteridine derivative, is a novel marker of monocyte and macrophage activation that is associated with atherosclerosis and cardiovascular risk in the general population. We examined the hypothesis that macrophage activation is associated with accelerated atherosclerosis in SLE and RA.

METHODS

We compared serum neopterin concentrations, adjusted for age, race, sex, and serum creatinine concentration, in patients with SLE (n=148) or RA (n=166) and control subjects (n=177). In patients with SLE or RA, serum neopterin concentrations were then tested for association (adjusted for age, race, sex, serum creatinine, and medication use) with measures of disease activity or damage, inflammatory markers and mediators, and coronary artery calcium measured by electron beam computed tomography.

RESULTS

Neopterin concentrations were significantly higher in patients with SLE (median 8.0, interquartile range [IQR] 6.5-9.8 nmoles/liter) and RA (median 6.7, IQR 5.3-8.9 nmoles/liter) than controls (median 5.7, IQR 4.8-7.1 nmoles/liter), and were higher in SLE patients than in RA patients (all P<0.001). In SLE, neopterin was significantly correlated with higher erythrocyte sedimentation rate (ESR; P=0.001), tumor necrosis factor α (P<0.001), monocyte chemoattractant protein 1 (P=0.005), and homocysteine concentrations (P=0.01), but in RA, it was only associated with ESR (P=0.01). Neopterin was not associated with coronary calcium in either SLE (P=0.65) or RA (P=0.21).

CONCLUSION

Macrophage activation, reflected by increased serum neopterin concentrations, was increased in both SLE and RA. Neopterin was more robustly associated with atherogenic mediators of inflammation and homocysteine in SLE than in RA, but was not associated with coronary atherosclerosis in either disease.

Early detection of Balkan endemic nephropathy in Bosanska Posavina

Balkan endemic nephropathy (BEN) is a chronic tubulointersticial nephropathy that is diagnosed in a few agrarian regions of Balkan. Even tough numerous dilemmas and conflicting opinions regarding BEN etiology are encountered in literature, prevailing theory is that BEN is caused by chronic poisoning with aristolochic acid ingested by food in people with genetic predisposition to this disease. BEN is categorized as a toxic tubulointerstitial nephropathy, with clinical picture and disease progression not differing from other tubulointerstitial nephropathies, but with insidious and gradual progression to end stage renal disease. There is no specific and sensitive diagnostic biomarkers for BEN and we use epidemiological and functional diagnostic criteria. It is considered that BEN affects up to 10% of population in endemic region. According to Renal Register of Bosnia and Herzegovina, there are around 15% of BEN patients on chronic dialysis program, but no official data on the number of predialysis BEN patients, because of lack of adequate demographic data and screening or systematic examinations of the population living in the affected region since 1991. The members of the Society of nephrology, dialysis and transplantation of Bosnia and Herzegovina organized screening in two villages of Bosanska Posavina, as a part of the "Program Program of detection of chronic kidney diseases in high-risk population in Bosnia and Herzegovina", project which was approved from International Society of nephrology. In this paper we analyze preliminary results of that Program and discuss previous studies about BEN in Bosnia and Herzegovina, particularly diagnostic criteria and biomarkers of BEN.

Offspring of parents with Balkan Endemic Nephropathy have higher C-reactive protein levels suggestive of inflammatory processes: a longitudinal study

Background

Despite the characteristic extensive tubulointerstitial fibrosis, Balkan Endemic Nephropathy (BEN) is usually considered a non-inflammatory disease.

Methods

We examined a marker of inflammation, C-reactive protein (CRP), in the offspring of patients with BEN, a population at risk for BEN, prior to development of established disease to determine if an inflammatory process could be identified in the early stages of the disease. In 2003/04, 102 adult offspring whose parents had BEN and a control group of 99 adult offspring of non-BEN patients were enrolled in this prospective study. This cohort was re-examined yearly for four consecutive years. Levels of serum CRP were measured in years 3 and 4 and compared between groups. The data were analyzed with mixed models.

Results

Compared to controls, offspring of BEN parents had statistically higher CRP levels in two consecutive years, suggestive of early inflammatory reactivity. Whenever the mother was affected by BEN (both parents, or mother only), serum CRP was significantly increased, but not if only the father had BEN. CRP was inversely related to kidney cortex width but not to markers or renal function.

Conclusion

Early stages of BEN may involve inflammatory processes. The observation of a maternal involvement supports the concept of fetal programming, which has been implicated in the pathogenesis of other chronic kidney diseases.

Etiology of Balkan endemic nephropathy and associated urothelial cancer

Balkan endemic nephropathy (BEN) is a familial chronic tubulointerstitial disease with insidious onset and slow progression to terminal renal failure. Evidence has accumulated that BEN is an environmentally induced disease. There are three actual theories attempting to explain the environmental cause of this disease: (1) the aristolochic acid hypothesis, which considers that the disease is produced by chronic intoxication with Aristolochia, (2) the mycotoxin hypothesis, which considers that BEN is produced by ochratoxin A, and (3) the Pliocene lignite hypothesis, which proposes that the disease is caused by long-term exposure to polycyclic aromatic hydrocarbons and other toxic organic compounds leaching into the well drinking water from low-rank coals in the vicinity to the endemic settlements. Moreover, it was suggested that BEN risk is influenced by inherited susceptibility. Therefore, it has been expected that molecular biological investigations will discover genetic markers of BEN and associated urothelial cancer, permitting early identification of susceptible individuals who may be at risk of exposure to the environmental agents. Since kidney pathophysiology is complex, gene expression analysis and highly throughput proteomic technology can identify candidate genes, proteins and molecule networks that eventually could play a role in BEN development. Investigation of gene-gene and gene-environment interactions could be the content of further studies determining the precise risk for BEN.

Serum neopterin, tumor necrosis factor-α and soluble tumor necrosis factor receptor II (p75) levels and disease activity in Egyptian female patients with systemic lupus erythematosus

OBJECTIVE

To determine the clinical value of assaying serum levels of neopterin, tumor necrosis factor-alpha (TNF-alpha) and soluble tumor necrosis factor receptor II (p75) (sTNFRII) in patients with systemic lupus erythematosus (SLE), manifested clinically with lupus nephritis (LN), neuropsychiatric lupus erythematosus (NPLE), and/or vasculitis compared with established parameters (complements C3 and C4).

PATIENTS AND METHODS

Serum concentrations of neopterin, TNF-alpha and sTNFRII were studied in 40 female patients with SLE at various degrees of disease activity and in 10 healthy controls, matched for age and sex, using an ELISA kit. Disease activity was assessed by the SLE disease activity index (SLEDAI) score. Thirty-five, 30 and 28 of our patients presented with LN, NPLE and/or vasculitis, respectively, as the main clinical manifestation.

RESULTS

Serum levels of neopterin, TNF-alpha and sTNFRII were significantly increased, while the TNF-alpha/sTNFRII ratio, C3 and C4 levels of SLE patients were significantly lower than those of healthy controls. Neopterin and sTNFRII were the only parameters that showed significantly higher levels in SLE patients with mild activity compared to normal subjects and were the only parameters that showed a significant elevation in membranous nephritis and in mild NPLE compared to patients without nephritis and NPLE. Patients with vasculitis had significant elevation of serum neopterin, TNF-alpha and sTNFRII levels compared to patients without vasculitis. We found significant correlations between all measured variables and the SLEDAI score. Also, serum neopterin levels showed significant positive correlation with serum TNF-alpha, sTNFRII and TNF-alpha/sTNFRII levels. Serum neopterin and sTNFRII could be used to identify SLE patients from normals with a sensitivity and specificity of 100%. Multivariate linear regression analysis showed that serum sTNFRII was the only significant independent variable among parameters for prediction of SLE disease activity.

CONCLUSION

We suggest that serum sTNFRII and neopterin are more sensitive markers of disease activity than TNF-alpha, C3 or C4. However, sTNFRII may be a clinically useful independent marker for prediction of SLE disease activity and to differentiate normal subjects from those having mild SLE.

Body weight, diet and water intake in preventing stone disease

Nutrition plays a major role in the pathogenesis of the most widespread forms of nephrolithiasis, i.e. calcium (calcium oxalate and phosphate) and uric acid stone disease. For this reason, dietary measures are the first level of intervention in primary prevention, as well as in secondary prevention of recurrences. An unbalanced diet or particular sensitivity to various foods in stone formers can lead to urinary alterations such as hypercalciuria, hyperoxaluria, hyperuricosuria, hypocitraturia and an excessively acid urinary pH. Over the course of time, these conditions contribute to the formation or recurrence of kidney stones, due to the effect they exert on the lithogenous salt profile. The fundamental aspects of the nutritional approach to the treatment of idiopathic nephrolithiasis are body weight, diet and water intake. This paper will present data resulting from our own investigations and the most significant evidence in literature.