Urinary C4d and progression of kidney disease in IgA vasculitis.

BACKGROUND: Immunoglobulin A (IgA) vasculitis nephritis (IgAVN) is the most common secondary IgA nephropathy (IgAN). Urinary C4d have been identified associated with the development and progression in primary IgAN; however, its role in kidney disease progression of IgAVN is still unclear. METHODS: This study enrolled 139 patients with IgAVN, 18 healthy subjects, 23 focal segmental glomerulosclerosis patients and 38 IgAN patients. Urinary C4d levels at kidney biopsy were measured using enzyme-linked immunosorbent assay. The association between urinary C4d/creatinine and kidney disease progression event, defined as 40% estimated glomerular filtration rate decline or end-stage kidney disease, was assessed using Cox proportional hazards models and restricted cubic splines. RESULTS: The levels of urinary C4d/creatinine (Cr) in IgAVN and IgAN patients were higher than in healthy controls. Higher levels of urinary C4d/Cr were associated with higher proteinuria and severe Oxford C lesions, and glomerular C4d deposition. After a median follow-up of 52.79 months, 18 (12.95%) participants reached composite kidney disease progression event. The risk of kidney disease progression event was higher with higher levels of Ln(urinary C4d/Cr). After adjustment for clinical data, higher levels of urinary C4d/Cr were associated with kidney disease progression in IgAVN [per Ln-transformed urinary C4d/Cr, hazard ratio 1.573, 95% confidence interval (CI) 1.101-2.245; P = .013]. Compared with the lower C4d/Cr group, the hazard ratio was 5.539 (95% CI 1.135-27.035; P = .034) for the higher levels group. CONCLUSIONS: Higher levels of urinary C4d/Cr were associated with kidney disease progression event in patients with IgAVN.

Intramuscular Immunization Induces Antigen-specific Antibodies in Urine.

Towards the development of vaccines against urinary tract infections (UTI), we determined the ability of intramuscular (i.m.) immunization to result in antigen-specific antibodies in urine. As a model antigen/vaccine, levels of total and vaccine-specific antibodies were determined in urine as a spin-out study of a phase 1 trial. Non-muscle-invasive bladder cancer (NMIBC) patients at different risks of progression, undergoing intravesical bacillus Calmette-Guérin (BCG) immunotherapy or not, received an adjuvanted recombinant protein vaccine that resulted in high titers of vaccine-specific serum immunoglobulin G (IgG) in all patients, regardless of the risk group. Vaccine-specific IgG and immunoglobulin A (IgA) were detected in urine of half of the patients at low risk of progression NMIBC and in all the intermediary/high- (int/high) risk patients. Vaccine-specific IgG titers were correlated to total urinary IgG levels, the latter being higher in the int/high-risk patients. In contrast, vaccine-specific IgA did not correlate to urinary IgA levels. Furthermore, vaccine-specific antibodies were transiently increased by intravesical BCG instillations. Altogether, our data show that a standard i.m. immunization can effectively induce antigen-specific antibodies in urine, which, upon selection of optimal vaccine targets, may provide protection against UTI. Vaccine-specific IgG titers were dependent on conditions affecting total urinary IgG levels, while production of vaccine-specific IgA in situ might independently contribute to protection against infections in the bladder. PATIENT SUMMARY: Towards the development of vaccines able to protect against urinary tract infections, we examined the potential of the intramuscular vaccination using a model antigen. We found two types of specific antibodies in the urine, which together may locally contribute to protection against infections, thus supporting the use of such a standard immunization route.

Urine and Free Immunoglobulin Light Chains as Analytes for Serodiagnosis of Hantavirus Infection.

Rapid point-of-care testing is a megatrend in infectious disease diagnosis. We have introduced a homogeneous immunoassay concept, which is based on the simultaneous binding of antigen and protein L to a given immunoglobulin molecule. The complex formation is detected utilizing time-resolved Förster resonance energy transfer between antigen-attached donor and acceptor-labeled protein L, hence the name LFRET. Here, we demonstrate that urine can be used as a sample matrix in LFRET-based serodiagnostics. We studied urine samples collected during the hospitalization and recovery of patients with acute Puumala orthohantavirus (PUUV) infection. We compared PUUV antibody-specific LFRET signals in urine to those in plasma, and found excellent correlation in the test outcomes The LFRET test from urine was positive in 40/40 patients with acute PUUV infection. PUUV causes a mild form of hemorrhagic fever with renal syndrome, characterized by acute kidney injury and proteinuria. Immunofluorescence and western blotting demonstrated PUUV-IgG and -IgA in urine, however, the presence of intact immunoglobulins did not fully explain the LFRET signals. We purified free light chains (FLCs) from both urine and serum of healthy volunteers and patients with acute PUUV infection, and verified the presence of antigen-specific FLCs. Antigen-specific FLCs provide a new means for non-invasive antibody detection and disease diagnosis.

Noninvasive Urinary Monitoring of Progression in IgA Nephropathy.

Standard methods for detecting and monitoring of IgA nephropathy (IgAN) have conventionally required kidney biopsies or suffer from poor sensitivity and specificity. The Kidney Injury Test (KIT) Assay of urinary biomarkers has previously been shown to distinguish between various kidney pathologies, including chronic kidney disease, nephrolithiasis, and transplant rejection. This validation study uses the KIT Assay to investigate the clinical utility of the non-invasive detection of IgAN and predicting the progression of renal damage over time. The study design benefits from longitudinally collected urine samples from an investigator-initiated, multicenter, prospective study, evaluating the efficacy of corticosteroids versus Rituximab for preventing progressive IgAN. A total of 131 urine samples were processed for this study; 64 urine samples were collected from 34 IgAN patients, and urine samples from 64 demographically matched healthy controls were also collected; multiple urinary biomarkers consisting of cell-free DNA, methylated cell-free DNA, DMAIMO, MAMIMO, total protein, clusterin, creatinine, and CXCL10 were measured by the microwell-based KIT Assay. An IgA risk score (KIT-IgA) was significantly higher in IgAN patients as compared to healthy control (87.76 vs. 14.03, p < 0.0001) and performed better than proteinuria in discriminating between the two groups. The KIT Assay biomarkers, measured on a spot random urine sample at study entry could distinguish patients likely to have progressive renal dysfunction a year later. These data support the pursuit of larger prospective studies to evaluate the predictive performance of the KIT-IgA score in both screening for non-invasive diagnosis of IgAN, and for predicting risk of progressive renal disease from IgA and utilizing the KIT score for potentially evaluating the efficacy of IgAN-targeted therapies.

First-void urine as a non-invasive liquid biopsy source to detect vaccine-induced human papillomavirus antibodies originating from cervicovaginal secretions.

BACKGROUND: Monitoring HPV antibodies non-invasively would be a major advantage for large epidemiological studies and follow-up of vaccinees. OBJECTIVES: This study investigated the presence of HPV-specific antibody transudates from systemic circulation in first-void urine of (un)vaccinated subjects and the agreement with paired sera. STUDY DESIGN: In this case-control study, 55 paired first-void urine and serum samples were included from 19- to 26-year-old women, unvaccinated (n = 19) or vaccinated (n = 36) with the bi- or quadrivalent HPV vaccine during adolescence (NCT02714114). Human IgA, total human IgG, and HPV6/11/16/18-Ig(M/G/A) were measured in paired samples. RESULTS: Significant positive Spearman rank correlations (rs) were found in HPV-specific antibody levels between paired samples (HPV6: rs = 0.777; HPV11: rs = 0.757; HPV16: rs = 0.876; HPV18: rs = 0.636 (p < 0.001)). In both first-void urine and serum, significantly higher HPV6/11/16/18 antibody levels were observed in vaccinated compared with unvaccinated women (p ≤ 0.017). CONCLUSIONS: The present study provides the first proof that vaccine-induced HPV antibodies are detectable in the first-void urine of young women. Moreover, significant positive correlations were observed between HPV6/11/16/18-antibodies in first-void urine and paired sera. Further optimization and validation are required to demonstrate its potential use in epidemiological studies and follow-up of HPV vaccination.

Determination immunogenic property of truncated MrpH.FliC as a vaccine candidate against urinary tract infections caused by Proteus mirabilis.

Proteus mirabilis is common cause of urinary tract infections (UTIs) especially in complicated UTIs which are resistant to antibiotic therapy, Consequently, an ideal vaccine is inevitably required. The N-terminal domain of MrpH (Truncated form of MrpH) lies between the most critical antigens of P. mirabilis to consider as vaccine candidate. FliC of Salmonella typhimurium induces several pathways of immunity system, which leads to produce antibody and cytokines. In this study, adjuvant properties of FliC and efficacy of truncated MrpH as important antigen, in tMrpH.FliC were determined in in vitro and in vivo circumstances. Three proteins including: FliC, MrpH and tMrpH.FliC were injected to mice and subsequently sera and supernatant of cell culture were collected to evaluate different immune responses. According to our findings, tMrpH.FliC could stimulate both humoral and cellular immune responses, so that serum IgG, urine IgA, IL.4, IFN-γ and IL.17 were increased significantly in comparison to MrpH and FliC alone, this augmentation was considerable. Results showed significant decrease of bacterial load in all of the challenged groups compared to the control group, although this protective effect was the highest in mice vaccinated with tMrpH.FliC. Our results showed truncated MrpH, without an unwanted domain is an ideal vaccine target and FliC, as adjuvant, increases its immunogenic property. Thus, fusion protein tMrpH.FliC can be considered as promising vaccine against P. mirabilis.

Efficacy of mizoribine and prednisolone combination therapy in adult patients with IgA vasculitis.

Immunoglobulin (Ig)A vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is one of the most common vasculitis caused by an IgA-mediated immune complex. It occurs most frequently in childhood and less commonly in adulthood. As for the treatment of IgAV in adults, there are few studies dealing with the administration and efficacy of intravenous pulse steroid therapy or combination therapy using prednisolone (PSL) and immunosuppressive drugs. Mizoribine (MZB) is a newly developed immunosuppressive drug with few adverse effects; however, there are currently few studies using MZB in adult patients with IgAV. In this study, we evaluated the efficacy of MZB combined with a course of PSL in adult patients with IgAV. Five patients with adult onset IgAV were enrolled in the study. All patients received oral PSL (initial dose 30-50 mg/day), and MZB was administered orally at a single morning dose of 150 mg. We investigated the clinical manifestations and prognosis of these patients receiving the combination therapy of MZB and PSL retrospectively. All patients showed complete or partial remission of proteinuria and microscopic hematuria with the combination therapy of MZB and PSL. Furthermore, no significant adverse effects were observed. Although this study had an uncontrolled small group, our results indicate that the combination of MZB with PSL could be a possible new treatment for adult patients with IgAV.

Biomarkers and targeted new therapies for IgA nephropathy.

IgA nephropathy (IgAN) has variable clinical presentation and outcome. There is a need to identify children who have the potential to progress to end stage renal disease (ESRD). Biomarkers related to the pathogenetic process of IgAN can detect risk factors and identify targets for new therapies. Galactose-deficient IgA1 (Gd-IgA1) is a specific biomarker of IgAN and could be the first treatment target. In experimental mice, reduction of IgA1 deposits and hematuria was observed after treatment with a bacterial protease that selectively cleaves human IgA1. Glycan-targeted drugs that may act to neutralize Gd-IgA1 inhibit abnormal enzymatic glycosylation of IgA1 or deplete cells producing Gd-IgA1. The autoimmune response to Gd-IgA1 produces autoantibodies that are sensitive and specific biomarkers of IgAN development and progression and suggests the possible benefits of anti-B cell therapies directed against CD20, B-cell activating factor (BAFF), or B cell receptor, and also proteasome inhibitors. The activation of complement in IgAN offers new biomarkers and the rationale for using complement inhibitors, including eculizumab. Renal pathological features represent sensitive biomarkers of added value over clinical data and may drive steroid therapy in selected cases. Finally, the hypothesis of the involvement of intestinal mucosal immunity in the pathogenesis of IgAN suggests the possibility of avoiding the systemic effect of steroid. Enteric budesonide targeting Peyer's patches at the ileocecal junction is an interesting option that has provided some preliminary favorable results in IgAN. In conclusion, the identification of new biomarkers is a promising area for therapies targeting IgAN in patients at risk of progression.

Toward Noninvasive Diagnosis of IgA Nephropathy: A Pilot Urinary Metabolomic and Proteomic Study.

IgA nephropathy is diagnosed by renal biopsy, an invasive procedure with a risk of significant complications. Noninvasive approaches are needed for possible diagnostic purposes and especially for monitoring disease activity or responses to treatment. In this pilot project, we assessed the utility of urine samples as source of biomarkers of IgA nephropathy. We used spot urine specimens from 19 healthy controls, 11 patients with IgA nephropathy, and 8 renal-disease controls collected on day of renal biopsy. Urine samples were analyzed using untargeted metabolomic and targeted proteomic analyses by several experimental techniques: liquid chromatography coupled with mass spectrometry, immunomagnetic isolation of target proteins coupled with quantitation by mass spectrometry, and protein arrays. No single individual biomarker completely differentiated the three groups. Therefore, we tested the utility of several markers combined in a panel. Discriminant analysis revealed that combination of seven markers, three metabolites (dodecanal, 8-hydroxyguanosine, and leukotriene C4), three proteins (α1-antitrypsin, IgA-uromodulin complex, and galactose-deficient IgA1), and heparan sulfate, differentiated patients with IgA nephropathy from patients with other renal diseases and healthy controls. Future studies are needed to validate these preliminary findings and to determine the power of these urinary markers for assessment of responses to therapy.

Galactose-Deficient IgA1 as a Candidate Urinary Polypeptide Marker of IgA Nephropathy?

In patients with IgA nephropathy (IgAN), circulatory IgA1 and IgA1 in mesangial deposits contain elevated amounts of galactose-deficient IgA1 (Gd-IgA1). We hypothesized that a fraction of Gd-IgA1 from the glomerular deposits and/or circulation may be excreted into the urine and thus represent a disease-specific biomarker. Levels of urinary IgA and Gd-IgA1 were determined in 207 patients with IgAN, 205 patients with other renal diseases, and 57 healthy controls, recruited in USA, Japan, and Italy. Urinary IgA was similarly elevated in patients with IgAN and renal-disease controls compared with healthy controls. However, urinary Gd-IgA1 levels were higher in patients with IgAN (IgAN, 28.0 ± 17.9; disease controls, 20.6 ± 17.4 units/mg urinary creatinine; P < 0.0001). Lectin western blotting data confirmed these results. In IgAN patients, levels of urinary Gd-IgA1 correlated with proteinuria (P < 0.001). When we purified IgA from serum and urine of an IgAN patient, the relative proportion of Gd-IgA1 to total IgA1 was higher in the urine compared with serum, suggesting selective excretion of Gd-IgA1 in IgAN. In summary, urinary excretion of Gd-IgA1 was elevated in patients with IgAN and the urinary Gd-IgA1 levels correlated with proteinuria. Urinary Gd-IgA1 may thus represent a disease-specific biomarker of IgAN.

Dengue Specific Immunoglobulin A Antibody is Present in Urine and Associated with Disease Severity.

The kinetics of dengue virus (DENV)-specific IgA antibody in urine and the potential correlation with disease severity remain elusive. In this study, 262 serial urine samples from 78 laboratory-confirmed patients were assayed by a commercial immunoglobulin A (IgA) kit against DENV. All cases were classified into dengue fever (DF) and severe dengue (SD) according to the 2009 WHO/TDR guideline. The total positive rate of IgA in urine was 59%. DENV-specific IgA was detected in urine from day 2 to day 13 after the onset of illness in DF patients; While for SD patients, anti-DENV IgA could be detected till day 14. The positive rate of IgA in patients with secondary infection was higher than that in patients with primary infection. Importantly, during 4-7 days after the onset of illness, the IgA positive rate of SD patients was significantly higher than that of DF patients. Especially, the intensity of IgA signal in SD patients was obviously stronger than that in DF patient at the recovery stage. Overall, our results suggested that the existence of DENV-specific IgA antibodies in urine might be a warning sign for the severity of disease and its measurement might provide valuable guidance for proper patient management.

Evaluation of the performances of six commercial kits designed for dengue NS1 and anti-dengue IgM, IgG and IgA detection in urine and saliva clinical specimens.

BACKGROUND: Rapid diagnostic tests (RDTs) have been commercialized in order to help physicians in dengue diagnosis. Until recently, only blood samples were used for those tests but it has been shown in several studies that urine and saliva can also be employed for dengue diagnosis. RDTs for the detection of NS1 antigen and anti-dengue IgG, IgM and IgA in urine and saliva specimens have thus been developed by Standard Diagnostics. The aim of this study was to evaluate the performances these new commercial assays. METHODS: Two panels of clinical specimens were used: one for the evaluation of the NS1-detection devices and the second for the evaluation of the antibody-detection kits. Each panel consisted of urine and saliva specimens collected sequentially from 86 patients with a confirmed dengue infection. A total of 291 saliva and 440 urine samples were included in the NS1-evaluation panel and 530 saliva and 528 urine specimens constituted the antibody-evaluation panel. All samples were tested in parallel by in-house ELISAs and by the commercial RDTs. RESULTS: The RDTs demonstrated an overall sensitivity of 15.5 %/27.9 %/10.7 % for NS1/IgG/IgA detection in urine samples and 20.4 %/ 34.8 %/11 %/6.2 % for NS1/IgG/IgM/IgA detection in saliva samples. Compared to the in-house NS1 ELISA, the results obtained with the NS1 RDT demonstrated a good correlation with urine samples (kappa coefficient: 0.88) but not with saliva specimens (kappa coefficient: 0.28). RDTs designed for antibody detection in saliva and urine were extremely specific (100 %), but less sensitive than the in-house ELISAs (i.e., reduction of the overall sensitivity by 12.2 % for the RDT designed for IgG detection in urine and by 23.7 % for the RDT detecting anti-DENV IgM in saliva). IgM were not detected in urine, either by RDT or ELISA. CONCLUSIONS: Although the RDTs evaluated here offer an apparently attractive approach for dengue diagnosis, this study suggests that these new commercial kits would require further improvement to increase the sensitivity.

Relationship between immune parameters and organ involvement in children with Henoch-Schonlein purpura.

Henoch-Schonlein purpura (HSP) is the most common type of connective tissue diseases which increasingly occurs in children in recent years and its pathogenesis remains unclear. In order to explore the immune parameters and underlying pathogenesis mechanism of children with HSP, the study involved 1232 patients with HSP having different clinical symptoms and their laboratory indicators were evaluated. Th1/Th2 imbalance and overactivity of Th2 cells can cause increase in the synthesis and release of immunoglobulins in children with HSP. The number of red blood cells and white blood cells in urine was directly proportional to the level of IgA and inversely proportional to the level of serum complements (C3 and C4). Activation of these complements caused by immunoglobulin in patients with HSP plays an important role in renal injury. The urinary protein content in children with HSP along with proteinuria was positively correlated with IgE level, and IgE mediated type 1 hypersensitivity can cause increase in capillary permeability and weakened the charge barrier; hence, it could be considered as one of the causes of proteinuria in HSP. Additionally, the NK cells percentage was reduced and impaired immune function of NK cells were related to the immune injury of the digestive tract and kidney.

Light chain crystalline kidney disease: diagnostic urine microscopy as the "liquid kidney biopsy".

Multiple myeloma (MM) is a plasma cell disorder, which often causes parenchymal kidney disease. Light chain (LC) cast nephropathy represents the most common renal lesion. In some instances, LC crystals precipitate within renal tubular lumens and deposit within proximal tubular cell cytoplasms. Importantly, urine microscopy in such patients can provide insight into the underlying LC-related lesion. Here we present two patients with MM complicated by acute kidney injury (AKI) where LC crystalline casts were observed on urinary sediment analysis. Kidney biopsy revealed acute tubular injury with LC crystal casts within both tubular lumens and renal tubular epithelial cell cytoplasms. These findings suggest that the urinary sediment may be a non-invasive way to diagnose LC crystalline-induced AKI in patients with MM.

Urine proteomes of healthy aging humans reveal extracellular matrix (ECM) alterations and immune system dysfunction.

Aging is a complex physiological process that poses considerable conundrums to rapidly aging societies. For example, the risk of dying from cardiovascular diseases and/or cancer steadily declines for people after their 60s, and other causes of death predominate for seniors older than 80 years of age. Thus, physiological aging presents numerous unanswered questions, particularly with regard to changing metabolic patterns. Urine proteomics analysis is becoming a non-invasive and reproducible diagnostic method. We investigated the urine proteomes in healthy elderly people to determine which metabolic processes were weakened or strengthened in aging humans. Urine samples from 37 healthy volunteers aged 19-90 years (19 men, 18 women) were analyzed for protein expression by liquid chromatography-tandem mass spectrometry. This generated a list of 19 proteins that were differentially expressed in different age groups (young, intermediate, and old age). In particular, the oldest group showed protein changes reflective of altered extracellular matrix turnover and declining immune function, in which changes corresponded to reported changes in cardiovascular tissue remodeling and immune disorders in the elderly. Thus, urinary proteome changes in the elderly appear to reflect the physiological processes of aging and are particularly clearly represented in the circulatory and immune systems. Detailed identification of "protein trails" creates a more global picture of metabolic changes that occur in the elderly.

Immunization with the yersiniabactin receptor, FyuA, protects against pyelonephritis in a murine model of urinary tract infection.

Urinary tract infections (UTI) are common and represent a substantial economic and public health burden. Roughly 80% of these infections are caused by a heterogeneous group of uropathogenic Escherichia coli (UPEC) strains. Antibiotics are standard therapy for UTI, but a rise in antibiotic resistance has complicated treatment, making the development of a UTI vaccine more urgent. Iron receptors are a promising new class of vaccine targets for UTI, as UPEC require iron to colonize the iron-limited host urinary tract and genes encoding iron acquisition systems are highly expressed during infection. Previously, three of six UPEC siderophore and heme receptors were identified as vaccine candidates by intranasal immunization in a murine model of ascending UTI. To complete the assessment of iron receptors as vaccine candidates, an additional six UPEC iron receptors were evaluated. Of the six vaccine candidates tested in this study (FyuA, FitA, IroN, the gene product of the CFT073 locus c0294, and two truncated derivatives of ChuA), only FyuA provided significant protection (P = 0.0018) against UPEC colonization. Intranasal immunization induced a robust and long-lived humoral immune response. In addition, the levels of FyuA-specific serum IgG correlated with bacterial loads in the kidneys [Spearman's rank correlation coefficient ρ(14) = -0.72, P = 0.0018], providing a surrogate of protection. FyuA is the fourth UPEC iron receptor to be identified from our screens, in addition to IutA, Hma, and IreA, which were previously demonstrated to elicit protection against UPEC challenge. Together, these iron receptor antigens will facilitate the development of a broadly protective, multivalent UTI vaccine to effectively target diverse strains of UPEC.

Local immune response in bladder pain syndrome/interstitial cystitis ESSIC type 3C.

INTRODUCTION AND HYPOTHESIS: Bladder pain syndrome/interstitial cystitis (BPS/IC) is identified based on subjective symptoms which lead to heterogeneous patient populations. Previous studies using gene expression arrays for BPS/IC with Hunner's lesions [European Society for the Study of Interstitial Cystitis (ESSIC) type 3C], a subtype of the condition discernible by cystoscopy, have revealed characteristic immune responses and urothelial abnormalities. This current study aimed to further characterize this subtype using a gene expression panel. We hypothesized that B-cell activation with high levels of urinary antibody concentration would be found. METHODS: Cold-cup bladder biopsies, catheterized urine and blood were collected from 15 BPS/IC ESSIC type 3C patients, 11 non-inflammatory overactive bladder (OAB) patients and eight healthy controls. Gene expression in biopsies was quantified by real-time quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry was performed on bladder tissue and urinary immunoglobulins G and A were quantified by enzyme-linked immunosorbent assay. Statistical analyses included the Kruskal-Wallis test for non-parametric data and post hoc tests identified differences between groups. RESULTS: High expression of T- and B-cell markers (CTLA4, CD20, CD79A, IGH@), low expression of urothelial markers (KRT20, UPK1B, UPK3A), focal lymphoid aggregates in the submucosa and high immunoglobulin concentration in urine were found exclusively in BPS/IC ESSIC type 3C patients. Results for OAB were in intermediate ranges between the other two groups and UPK1B even reached significantly lower expression when compared to healthy controls. CONCLUSIONS: BPS/IC ESSIC type 3C is characterized by a local adaptive immune response with elevated urinary antibody concentrations. Quantification of urinary immunoglobulin levels could be used for a non-invasive diagnosis of BPS/IC ESSIC type 3C.

The complex of immunoglobulin A and uromodulin as a diagnostic marker for immunoglobulin A nephropathy.

BACKGROUND: The only tool to diagnose immunoglobulinn A nephropathy (IgAN) is renal biopsy which requires hospitalization; moreover, renal biopsy has a risk of critical bleeding. Therefore, a non-invasive method for accurate diagnosis of IgAN is desirable and a must-to-have tool for the clinics. For this purpose, we evaluated the diagnostic value of the IgA-uromodulin complex in the urine of patients with IgAN for its feasibility and adequacy. METHOD: We determined the IgA-uromodulin complex as a candidate for a diagnostic marker of IgAN by immunoprecipitation, liquid chromatography-mass spectrometry (LC-MS) and Western blot analysis. The enzyme-linked immunosorbent assay (ELISA) for the IgA-uromodulin complex was developed and applied to urine samples obtained from various kidney disease patients. RESULT: One hundred and three of 126 urine samples (81.7%) from IgAN patients were positive for the IgA-uromodulin complex, while only 25 out of 94 urine samples (26.6%) in other kidney disease patients were positive. Sensitivity was 81.7%, specificity was 73.4%, and diagnosis efficiency was 78.2%. The complex was negative in eight urine samples obtained from patients with Alport syndrome which is almost impossible to discriminate from IgAN by routine urinalysis. CONCLUSION: Detection of the urinary IgA-uromodulin complex by ELISA is a useful non-invasive method to diagnose IgAN.

Diagnostic values of parasite-specific antibody detections in saliva and urine in comparison with serum in opisthorchiasis.

Infection by the liver fluke (Opisthorchis viverrini) causes hepatobiliary disease and bile duct cancer (cholangiocarcinoma, CCA) in endemic areas in Southeast Asia. Measurements of humoral immune response particularly parasite-specific antibodies are useful not only for serodiagnosis but they have been implicated as risk factors of CCA. In this study, we used indirect Enzyme Immunosorbent Assay (ELISA) to measure O. viverrini-specific immunoglobulins in serum, urine and saliva and assessed efficacies in diagnosis of opisthorchiasis and evaluated the relationship of antibodies among clinical specimens in a sample population in endemic areas in Khon Kaen, Thailand. By employing the Receiver Operation Characteristics (ROC) analysis, diagnostic efficacy based upon the area under the curve (AUC) revealed that serum, salivary IgG and IgA performed better than urine for diagnosis of opisthorchiasis. Seropositive cases were found in both parasite egg-negative as well as O. viverrini egg-positive groups. The levels of serum IgG correlated with intensity of O. viverrini infection (P<0.05). Diagnostic sensitivities based on serum and salivary IgG, IgA also positively associated with the intensity of infection. Correlations between serum antibodies and those in saliva were found to be greater in egg-negative than egg-positive individuals for O. viverrini. Our findings indicated a complex interrelation between antibody responses in different clinical specimens triggered by liver fluke infection. More comprehensive examinations are needed to determine the potential utility of salivary antibody detection which, in combination with the conventional fecal examination method, may better assist in the identification of individuals with opisthorchiasis. Furthermore, it may provide a better indicator of the risk of disease, particularly CCA.