Use of urinary γ-glutamyl transferase (GGT) to monitor the pattern of proteinuria in dogs with leishmaniasis treated with N-methylglucamine antimoniate.

The aim of this study was to assess if the coupled analysis of the urinary protein to creatinine (UPC) ratio and of the GGT/UC ratio (the ratio between urinary γ-glutamyl transferase activity and urinary creatinine) may be used in treated leishmaniotic dogs to differentiate dogs with transient impairment of tubular function from dogs with persistent tubular damage. To this aim, 40 urine from 10 proteinuric and leishmaniotic dogs that at the first visit had high GGT/UC ratio, consistent with tubular damage, were collected and analyzed before treatments and 2, 4 and 6 weeks after treatment with N-methylglucamine antimoniate and allopurinol. Compared with pre-treatment values, at the end of the study period the UPC ratio decreased only in 5/10 dogs, which, however, were still proteinuric or borderline proteinuric. Conversely, the GGT/CU ratio decreased in 8/10 dogs and in 3 of them the values at the end of the study period were below the threshold consistent with tubular proteinuria. The GGT/UC values at 6 weeks was significantly lower than before treatment. However, transient increases were frequent for both the analytes. These results indicate that in most of the dogs that remain proteinuric after treatment, likely due to the persistent glomerular damage, the GGT/UC ratio tends to normalize. This suggests that in these dogs tubular proteinuria at admission depends on functional impairment of tubular cells likely due to the overflow of proteins from damaged glomeruli. However, tubular proteinuria occasionally persists, suggesting that tubulointerstitial damages persist even in dogs responsive to treatments.

Evaluation of various biomarkers for kidney monitoring during canine leishmaniosis treatment.

BACKGROUND: The objective of this study was to evaluate and compare the evolution of the profile currently recommended by the International Renal Interest Society (IRIS) (sCr, UPC and sSDMA) with a panel of other different kidney biomarkers during treatment for canine leishmaniosis. This panel included three urinary glomerular biomarkers (uIgG, uCRP and uferritin) and three urinary tubular biomarkers (uGGT, uNAG and uRBP). These biomarkers were measured in two groups of dogs with canine leishmaniosis at IRIS stage I. Group 1: dogs showing proteinuria (UPC > 0.5) before treatment which did not decrease after treatment; Group 2: dogs showing proteinuria before treatment which decreased after treatment. RESULTS: Group 1 showed no significant changes in any biomarker after treatment. In group 2, among the biomarkers recommended by the IRIS, only UPC showed a significant decrease after treatment. However all biomarkers of glomerular damage showed a significant decrease after treatment, with uIgG/Cr and uCRP/Cr showing the greater decreases. In addition uRBP/Cr and uNAG/Cr showed significant decreases after treatment. CONCLUSIONS: In dogs with leishmaniosis at IRIS stage I that reduced UPC after treatment, there were no significant changes in serum creatinine and sSDMA. However, all the urine biomarkers evaluated with exception of uGGT showed a significant decrease. These decreases were more evident in those markers related with glomerular function, being uIgG/Cr the biomarker more associated with UPC. Further studies involving a larger number of animals and histological analysis of the kidney would be recommended to confirm these findings and evaluate the routine practical use of these urine biomarkers in canine leishmaniosis.

Urinary gamma-glutamyl transferase (GGT) as a marker of tubular proteinuria in dogs with canine leishmaniasis, using sodium dodecylsulphate (SDS) electrophoresis as a reference method.

In order to assess if urinary γ- glutamyl transferase (GGT) identify tubular proteinuria in leishmaniotic dogs, the GGT/urinary creatinine (UC) ratio was calculated in 39 leishmaniotic dogs. According to sodium dodecylsulphate-agarose gel electrophoresis, the dogs had albuminuria (A, n = 10), glomerular (G, n = 3), tubular (T, n = 4) or mixed proteinuria (M, n = 22). The median GGT/UC ratio was 0.3, 0.3, 2.2, and 7.5, in groups G, A, M, and T, respectively. Statistically significant differences were found between groups G and M (P = 0.002), G and T (P <0.001), A and M (P <0.001), and A and T (P <0.001). Median values were higher in dogs with tubular components of proteinuria (M/T, 2.5) than in dogs without tubular components of proteinuria (A/G, 0.3), and in dogs with tubular proteinuria (T, 7.5) than in dogs with non-tubular proteinuria (NT, 1.0). GGT/UC values >0.81 or >2.64 could identify dogs in the M/T or T groups, respectively. Therefore, GGT/UC might be useful for the management of leishmaniotic dogs.

Variation of proteinuria in dogs with leishmaniasis treated with meglumine antimoniate and allopurinol: a retrospective study.

A retrospective study was performed using 53 client owned dogs with leishmaniasis to determine whether the degree of proteinuria, evaluated by the urine protein/creatinine ratio (UP/C), changes following treatment with meglumine antimoniate and allopurinol. Medical records of dogs with leishmaniasis in clinical stage C (according to the Canine Leishmaniasis Working Group staging system) and either proteinuric or borderline proteinuric (according to the International Renal Interest Society [IRIS] staging system) were reviewed. All dogs were treated with meglumine antimoniate and allopurinol for 4-8 wk. After treatment, UP/C, total protein, and total globulin significantly decreased and albumin and the albumin/globulin ratio (A/G) increased. After treatment, 7 of the 53 dogs (13.4%) became nonproteinuric following either a proteinuric or borderline proteinuric stage. Moreover, 12 of the 53 proteinuric dogs (22.6%) changed their stage to borderline proteinuric. The antileishmaniasis treatment with meglumine antimoniate in combination with allopurinol in dogs significantly reduced the degree of proteinuria in a short period of time. The results of the current study may be useful to the veterinary practitioner in the clinical management of canine leishmaniasis (CanL) in dogs with proteinuric chronic kidney disease.

Serum and urinary adiponectin in dogs with renal disease from leishmaniasis.

The objective of this study was to perform an analytical validation of a commercially available ELISA kit (human adiponectin) for urinary adiponectin determination in dogs, and to evaluate urinary adiponectin in dogs with glomerular injury. For this purpose, urine samples from three healthy dogs and three dogs with diagnosed kidney disease were used for analytical validation of the method. In order to evaluate possible influence of kidney damage on urinary adiponectin, serum and urine samples from six healthy and 58 dogs with leishmaniasis were included. The diseased dogs were allocated to three groups according to their urine protein/creatinine (UPC) ratio as non-proteinuric (NP), borderline proteinuric (BP), and proteinuric (P). Intra- and inter-assay coefficients of variation (CV) were lower than 10 per cent and 12 per cent, respectively. Dilutions of canine urine samples resulted in linear regression equations close to 1. Mean recovery was of 112 per cent. The detection limit was 0.75 ng/ml. Urinary adiponectin and urinary adiponectin/creatinine (UAC) ratio showed significantly higher values in urine of P group dogs compared with healthy, NP and BP dogs. In conclusion, an ELISA kit can be used for precise and accurate urinary adiponectin measurement in dogs. Urinary adiponectin is increased in dogs with proteinuria suggesting its possible use as a marker of kidney damage.

Urinary clusterin as a renal marker in dogs.

A validation of a species-specific enzyme immunoassay for urinary clusterin measurement in dogs was performed, and the use of urinary clusterin as a marker of renal damage was evaluated in a population of dogs with leishmaniasis. Urine was obtained from 75 dogs; 64 dogs had leishmaniasis and 11 were healthy. The dogs with leishmanias were divided into 5 groups: I (n = 9; serum creatinine [SCr] < 1.4 mg/dl, urinary protein-to-creatinine [UPC] ratio ≤ 0.5); II (n = 29; SCr < 1.4 mg/dl, UPC > 0.5); III (n = 6; SCr ≥ 1.4 mg/dl to <2 mg/dl, UPC > 0.5); IV (n = 13; SCr ≥ 2 mg/dl to <5 mg/dl, UPC > 0.5); and V (n = 7; SCr ≥ 5 mg/dl, UPC > 0.5). The urinary clusterin concentration was measured, and the urinary clusterin-to-creatinine ratio was calculated. Canine urinary clusterin assay showed good analytical performance based on precision accuracy and limit-of-detection results. There was a statistically significant increase in urinary clusterin and clusterin-to-creatinine ratio in groups II-V compared with group I and healthy group. The results of the current study showed that urinary clusterin concentration and urinary clusterin-to-creatinine ratios are increased in dogs with analytical evidences of renal damage and that the urinary clusterin-to-creatinine ratio might be used as a potential early biomarker of chronic kidney disease.

Anti-Leishmania IgA in urine samples from dogs with clinical leishmaniasis.

Recently, anti-Leishmania IgG has been detected in urine samples from Leishmania-infected dogs and its concentrations have been correlated with impairment of renal function. The presence and relationship with other anti-Leishmania Ig isotypes in urine have not yet been investigated. The current study analyzed the concentrations of anti-Leishmania IgA and IgG in sera (Ig-S) and urine (Ig-U) samples by ELISA in 64 untreated dogs with clinical leishmaniasis. All 64 serum samples tested were positive for anti-Leishmania IgG. Fifty of them (78.1%) were also positive for anti-Leishmania IgA. The results showed the presence of anti-Leishmania IgA-U in 38% of the 50 dogs that were positive for specific IgA-S. Thirty-eight of the 64 dogs positive for Leishmania-specific IgG-S (59.4%) were also positive for Leishmania-specific IgG in urine (IgG-U). The concentrations of anti-Leishmania IgA-U were significantly correlated with urine protein/creatinine (uP/C) ratio (rho=0.542; P<0.001) and with serum biochemical parameters, such as gamma-globulins, urea and creatinine. Goldmann-Witmer coefficient (C value) indicated that detection of specific IgA in urine samples from dogs with leishmaniasis might not only be due to impairment of filtration of the glomerular barrier but also be due to local production of this isotype, which might reflect a local immunological response to the presence of the parasite in the genitourinary tract. Anti-Leishmania IgG-U concentrations were highly correlated with uP/C ratio (rho=0.779; P<0.001) and C value did not support in any case local production of this isotype. IgG isotype might be a more suitable and specific tool to evaluate renal damage due to the lower IgA-U sensitivity and correlation coefficients and evidence of IgA local production. However, dogs found positive for both Ig isotypes in urine presented significantly higher specific IgG-U concentrations and higher uP/C ratios than dogs found positive only for IgG-U, thus suggesting that the first group suffered more severe renal damage. This fact makes it necessary to evaluate the prognosis of dogs showing both anti-Leishmania IgA-U and IgG-U in future studies.

Anti-histone antibodies in dogs with leishmaniasis and glomerulonephritis.

The association between serum anti-histone antibodies and glomerulonephritis was studied in 43 dogs with leishmaniasis (Leishmania infantum). Dogs with increased serum creatinine levels and urine protein-creatinine ratio >1 were considered to have glomerulonephritis. Moderately elevated anti-histone antibodies were found in 38.89% (7/18) of infected dogs without glomerulonephritis, whereas 88% of dogs with glomerulonephritis (22/25) showed moderate or strongly elevated anti-histone antibodies. Prevalence of positive anti-histone antibodies reactions and mean serum concentration was significantly higher (P<0.001; P<0.0001) in infected dogs with glomerulonephritis. Correlation between anti-histone antibodies and urine protein-creatinine ratio was significant when groups were analysed together (P<0.046). Positive predictive value for glomerulonephritis of positive anti-histone antibodies was 88%. In conclusion, high anti-histone antibodies are significantly associated with glomerulonephritis. Although other factors must be involved, dogs with moderate or strong positive anti-histone antibodies reactions may have a higher probability to develop glomerular lesions in canine leishmaniasis.

Detection of anti-Leishmania immunoglobulin G antibodies in urine specimens of dogs with leishmaniasis.

For years, anti-Leishmania immunoglobulin G (IgG) antibodies have been detected in the sera of dogs living in areas of leishmaniasis endemicity. They have also been found in the aqueous humor and cerebrospinal fluid. In contrast, a review of the literature failed to identify the detection of anti-Leishmania antibodies in urine samples from dogs with leishmaniasis. Ninety-five dog urine samples were examined for the presence of anti-Leishmania antibodies by using a protein A enzyme-linked immunosorbent assay (ELISA). Twenty additional urine samples were collected from healthy dogs as controls. An IgG2 ELISA was performed on 26 urine samples found positive by the protein A ELISA. Twenty-three urine samples found positive to anti-Leishmania antibodies were tested for the local production of anti-Leishmania antibodies in the urinary tract by means of the urine antibody coefficient. Ten urine samples (and the corresponding serum samples) were compared by Western blot (WB) analysis. Thirty-five out of the 95 urine samples were found positive, 57 were found negative, and 3 were found inconclusive for antibody detection by the protein A ELISA. A high correlation between protein A and IgG2 levels was found in positive urine samples. Anti-Leishmania antibodies were present in the urine of dogs that had leishmaniasis, urinary protein/creatinine (U P/C) ratios of greater than one, and normal urinary sediment. A statistically significant correlation was observed between the U P/C ratios and the levels of anti-Leishmania antibodies in positive urine samples. In general, WB analysis and the urine antibody coefficient suggested that the presence of anti-Leishmania antibodies in urine was the consequence of an impairment of filtration of the glomerular barrier. However, in some dogs, WB analysis could be interpreted as suggesting that the presence of anti-Leishmania antibodies was caused, to a lesser extent, by local antibody production in the urinary tract. Antibody detection in urine could be a noninvasive method for leishmaniasis diagnosis and prognosis in dogs with glomerulonephropathies.

Glomerular lesions in dogs infected with Leishmania organisms.

OBJECTIVE: To histologically identify glomerular lesions in dogs infected with Leishmania organisms. ANIMALS: 41 dogs (17 sexually intact males and 14 sexually intact and 10 ovariohysterectomized females) that had positive results when tested for leishmaniosis as determined by use of serologic evaluation (indirect fluorescent antibody test, titers of 1:80 to 1:640) and direct microscopic identification of the protozoal organisms. PROCEDURE: Urine samples were collected by use of cystocentesis and examined by qualitative SDS-agarose gel electrophoresis (AGE). All dogs had non-selective (glomerular) or mixed (glomerular and tubular) proteinemia. Specimens were obtained from each dog during ultrasound-assisted renal biopsy and used for histologic examination. Each specimen was stained with H&E, periodic acid-Schiff, Goldner's trichrome, methenamine silver, and Congo Red stains. Specimens were adequate for evaluation when they contained at least 5 glomeruli/section, except for specimens stained with Congo Red in which 1 glomerulus/section was adequate. RESULTS: Examination of renal biopsy specimens revealed various glomerular lesions in all dogs and interstitial or tubular (or both) lesions in 23 of 41 (55%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Glomerular lesions that develop in dogs during infection with Leishmania organisms can be classified histologically as mesangial glomerulonephritis, membranous glomerulonephritis, membranoproliferative glomerulonephritis, and focal segmental glomerulonephritis. Tubulointerstitial histopathologic conditions were not observed as the primary lesion, despite being evident in 23 of 41 (55%) dogs. Use of SDS-AGE for qualitative evaluation of proteinuria and successive collection of specimens during renal biopsies following diagnosis of nonselective glomerular proteinuria provides the possibility for early identification of renal lesions.

SDS-PAGE and Western blot of urinary proteins in dogs with leishmaniasis.

Canine leishmaniasis is an endemic disease in the Mediterranean area caused by the protozoan Leishmania infantum, which usually produces renal failure. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blot using antibodies to IgG and IgA from dogs were carried out in the urine of 22 dogs with leishmaniasis diagnosed by ELISA and confirmed by PCR, and 20 healthy dogs. The results were compared to renal function laboratory tests and to those from a histopathological study of the kidneys from sick animals that died naturally or were euthanized. Five different bands with molecular weights ranging from 10 to 110 kDa were obtained from the electrophoresis of the urine of healthy dogs. 33.5% of total proteins corresponded to low molecular weight proteins and the other proteins had middle and high molecular weights. However, in the group with leishmaniasis, a maximum of 11 different bands with molecular weights ranging from 10 kDa to 150 kDa were displayed in the electrophoresis of the urine. The urine electrophoretic pattern in the sick dogs was classified as mixed (proteins with high and low molecular weights) because low molecular weight proteins made up 57.9% and the rest of the proteins had middle and high molecular weights. In Western blot, none of the healthy dogs showed excretion of IgG and/or IgA, whereas IgG and IgA were detected in the Western blot of urine of 68% and 55% respectively of dogs with leishmaniasis. The results obtained in the leishmaniasis group agreed with glomerular and tubular damage, which were confirmed by the histopathological findings.

Monitoring of total antimony and its species by ICP-MS and on-line ion chromatography in biological samples from patients treated for leishmaniasis.

Results from a study are reported in which patients with leishmaniasis were monitored by whole blood, blood plasma, urine, and hair analysis, before, during, and after intramuscular administration of N-methyl meglumine antimoniate. Quadrupole ICP-MS was used for the detection of antimony and on-line ion chromatography for the separation of its species. After typically 30 consecutive daily injections of 5 mg antimony per kg of body weight, Sb concentrations of up to 250 microg L(-1) in whole blood and plasma, and 60 mg of Sb per gram of creatinine in urine, were measured 24 h after drug administration. Antimony in hair samples of these patients showed concentrations of up to 24 microg g(-1). Speciation studies of Sb5+ and Sb3+ in drug, urine, and plasma samples were performed by ion chromatography using a Hamilton PRP-100X anion exchange column and EDTA (2 or 20 mM, pH 4.7) as the mobile phases. Repeatability of elution time and peak area measurements for a 0.125 ng spike were <1.2% and <3.5%, respectively. Method detection limits for both species, using a 1:10 diluted urine or plasma sample, were typically 1.6 microg L(-1). The procedure was capable of separating the very intense drug peak from its inorganic species, thus permitting the first studies on the bio-transformation of N-methyl meglumine antimoniate to Sb5+ and Sb3+ in the human body.