Growth arrest-specific protein 6 as a marker of nephritis in systemic sclerosis and juvenile systemic lupus erythematosus patients.

Background: Renal impairments commonly occur as a complication of autoimmune connective tissue diseases (CTDs). Therefore, early nephritis prediction is vital for patient outcomes. Growth Arrest-Specific Protein 6 (GAS6) was found to be upregulated in many types of inflammatory renal disease, including diabetic nephropathy.Aim: To evaluate GAS6 as a predictor of renal impairment in adults with systemic sclerosis (SSc) and children with systemic lupus Erythematosus (SLE).Methods: The study included 60 patients with SSc and 40 children with SLE. The serum level of GAS6 was measured using the ELISA technique. In adults with SSc, total proteins in 24-h urine concentration of >300 mg/24 h indicated renal inflammation, while in children with SLE, nephritis was diagnosed by abnormal renal pathology.Results: In SSc patients, GAS6 significantly increased in patients with proteinuria. GAS6 is an independent predictor of nephritis with an odds ratio (OR) of 1.06 and a 95% confidence interval (CI) of 1.0-1.1. at cutoff 12.2 ng/mL GAS6 predicted proteinuria with sensitivity 86.7% (95% CI: 59.5% to 98.3%), specificity 57.8% (95% CI: 42.1% to 72.3%), positive predictive value 40.6% (95% CI: 31.5% to 50.4%), negative predictive value 92.9% (95% CI: 77.7% to 97.73%), and accuracy 65.0% (95% CI: 51.6% to 76.9%). In SLE patients, Serum GAS6 did not differ significantly between children with and without lupus nephritis.Conclusion: GAS6 is an independent predictor of nephritis in patients with SSc. However, there is no association between GAS6 and nephritis in juvenile patients with SLE.

Exploring potential predictors of Henoch-Schönlein purpura nephritis: a pilot investigation on urinary metabolites.

Henoch-Schönlein purpura nephritis (HSPN) is the most severe manifestation of Henoch-Schönlein purpura (HSP). This study aimed to determine the role of urine metabolomics in predicting HSPN and explore the potential mechanisms of HSP. A liquid chromatography-tandem mass spectrometry-based untargeted metabolomics analysis was performed to investigate the urinary metabolic profiles of 90 participants, comprising 30 healthy children (group CON) and 60 patients with HSP, including 30 HSP patients without renal involvement (group H) and 30 HSPN patients (group HSPN). The differentially expressed metabolites (DEMs) were identified using orthogonal partial least squares discriminant analysis (OPLS-DA), and subsequent bioinformatics analysis was conducted to elucidate the perturbed metabolic pathways. A total of 43 DEMs between H and HSPN groups were analyzed by the Kyoto Encyclopedia of Gene and Genome (KEGG) database, and the result indicates that glycine, serine and threonine metabolism, and cysteine and methionine metabolism were significantly disturbed. A composite model incorporating propionylcarnitine and indophenol sulfate was developed to assess the risk of renal involvement in pediatric patients with HSP.   Conclusion: This study reveals the metabolic alterations in healthy children, HSPN patients, and HSP patients without renal involvement. Furthermore, propionylcarnitine and indophenol sulfate may be potential predictive biomarkers of the occurrence of HSPN. What is Known: • HSP is the predominant type of vasculitis observed in children. The long-term prognosis of HSP is contingent upon the extent of renal impairment. In severe nephritis, a delay in appropriate treatment may lead to fibrosis progression and subsequent development of chronic kidney disease (CKD), even leading to renal failure. • The application of metabolomics in investigating diverse renal disorders has been documented. Urine is a robust and sensitive medium for metabolomics detection. What is New: • The metabolic profiles were identified in urine samples of healthy children and those with HSP at the early stage of the disease. Different metabolites were identified between HSP patients without nephritis and those who developed HSPN. • These different metabolites may affect oxidative stress in the progression of HSPN.

Urine Biomarkers of Kidney Tubule Health, Injury, and Inflammation are Associated with Progression of CKD in Children.

BACKGROUND: Novel urine biomarkers may improve identification of children at greater risk of rapid kidney function decline, and elucidate the pathophysiology of CKD progression. METHODS: We investigated the relationship between urine biomarkers of kidney tubular health (EGF and α-1 microglobulin), tubular injury (kidney injury molecule-1; KIM-1), and inflammation (monocyte chemoattractant protein-1 [MCP-1] and YKL-40) and CKD progression. The prospective CKD in Children Study enrolled children aged 6 months to 16 years with an eGFR of 30-90ml/min per 1.73m2. Urine biomarkers were assayed a median of 5 months [IQR: 4-7] after study enrollment. We indexed the biomarker to urine creatinine by dividing the urine biomarker concentration by the urine creatinine concentration to account for the concentration of the urine. The primary outcome was CKD progression (a composite of a 50% decline in eGFR or kidney failure) during the follow-up period. RESULTS: Overall, 252 of 665 children (38%) reached the composite outcome over a median follow-up of 6.5 years. After adjustment for covariates, children with urine EGF concentrations in the lowest quartile were at a seven-fold higher risk of CKD progression versus those with concentrations in the highest quartile (fully adjusted hazard ratio [aHR], 7.1; 95% confidence interval [95% CI], 3.9 to 20.0). Children with urine KIM-1, MCP-1, and α-1 microglobulin concentrations in the highest quartile were also at significantly higher risk of CKD progression versus those with biomarker concentrations in the lowest quartile. Addition of the five biomarkers to a clinical model increased the discrimination and reclassification for CKD progression. CONCLUSIONS: After multivariable adjustment, a lower urine EGF concentration and higher urine KIM-1, MCP-1, and α-1 microglobulin concentrations were each associated with CKD progression in children.

Abnormal circadian rhythm of urinary sodium excretion correlates closely with hypertension and target organ damage in Chinese patients with CKD.

Whether the abnormal circadian rhythm of urinary sodium excretion is associated with hypertension in chronic kidney disease (CKD) is poorly understood. In this study, we assessed the relationship between the circadian rhythm of urinary sodium excretion and hypertension. Urinary samples were collected during both the day (07:00 to 22:00) and night (22:00 to 07:00) to estimate night/day urinary sodium excretion ratios. Blood pressure (BP) and clinical data were also measured. A total of 1,099 Chinese CKD patients were recruited, 308 patients were excluded, and 791 patients were final enrolled in this study. Among them, 291 patients were normotensive and 500 were hypertensive CKD patients. A 1:1 propensity score matching (PSM) analysis was performed with age and estimated glomerular filtration rate (eGFR) matched between 190 normotensive and hypertensive patients. In the full cohort and PSM cohort, multivariate regression analysis showed that the night/day urinary sodium excretion ratio was an independent risk factor for clinical hypertension, whereas 24 h urinary sodium excretion, diurnal and nocturnal urinary sodium excretion were not. When the night/day urinary sodium excretion ratios were further divided into tertiles (tertile 1 < 0.47, tertile 2, 0.47-0.84 and tertile 3 > 0.84), multivariate analysis showed that tertile 3 was independently associated with hypertension in the full and PSM cohorts. In addition, tertile 3 was also independently associated with eGFR ≤ 60 mL/min/1.73 m2 and left ventricular hypertrophy. These data suggested that an abnormal circadian rhythm of urinary sodium excretion was independently associated with hypertension and target-organ damage. Individualized salt intake and therapeutic strategies should be used to normalize the natriuretic dipping profile in CKD patients.

Urine Ammonium Predicts Clinical Outcomes in Hypertensive Kidney Disease.

Metabolic acidosis is associated with poor outcomes in CKD. Because impaired renal ammonium excretion is important in the pathogenesis of acidosis, urine ammonium excretion might be a better and perhaps earlier acid-base indicator of risk than serum bicarbonate, particularly in patients without acidosis. We evaluated the association between baseline ammonium excretion and clinical outcomes in African American Study of Kidney Disease and Hypertension participants (n=1044). Median daily ammonium excretion was 19.5 (95% confidence interval [95% CI], 6.5 to 43.2) mEq. In Cox regression models (adjusted for demographics, measured GFR, proteinuria, body mass index, net endogenous acid production, and serum potassium and bicarbonate), hazard ratios of the composite outcome of death or dialysis were 1.46 (95% CI, 1.13 to 1.87) in the low tertile and 1.14 (95% CI, 0.89 to 1.46) in the middle tertile of daily ammonium excretion compared with the high tertile. Among participants without acidosis at baseline, the adjusted hazard ratio for those with ammonium excretion <20 mEq/d was 1.36 (95% CI, 1.09 to 1.71) compared with those with ammonium excretion ≥20 mEq/d. Additionally, compared with participants in the high ammonium tertile, those in the low ammonium tertile had higher adjusted odds of incident acidosis at 1 year (adjusted odds ratio, 2.56; 95% CI, 1.04 to 6.27). In conclusion, low ammonium excretion is associated with death and renal failure in hypertensive kidney disease, even among those without acidosis. Low ammonium excretion could identify patients with CKD and normal bicarbonate levels who might benefit from alkali before acidosis develops.

NEPHROPATHY IN EARLY RHEUMATOID ARTHRITIS PATIENTS: DOES A SIGNIFICANT RISK EXIST?

Objective of the study layed in assessment of the pathophysiological relation between cell-mediated immunity (tumor necrosis factor-alpha (TNF-α) inflammatory cytokine) activation and renal dysfunction in the patients with early rheumatoid arthritis. We analyzed the data from 35 early rheumatoid arthritis (RA) patients of average age of 50,71±2,25 years (ranged 18-76 years, 80% of women) with 9,21±0,43 months mean duration of the disease by the time of the study initiation. Urine and blood tests were performed to verify the main indicators of kidney function and inflammation cytokines significant interaction. All signs of renal dysfunction at the baseline in the patients with early RA were associated with glomerular filtration rate decrease and excretion of urine protein increase. Dynamics of albuminuria, according to the analysis of variance for one-factor scheme, were significantly determined by the state of disease activity, reflecting the severity of joint damage. High urine ß-2-microglobulin level was significantly associated with the expression rate of main inflammatory cytokines as per binary regression analysis. The obtained dependence showed the dynamics of expression of tubular disorders in early RA with a progressive deterioration which did associate with the levels of TNF-α expression, and variety of the urine miсroglobulin rates in the interval 200-350 µg/L. Reliable correlation (r=0.51, p<0.05) between beta-2-microglobulinuria and TNF-α levels was clearly shown, revealing the relationship described by the formula MGU=- 81+937×log10 (TNF-α) as per regression analysis. The severity of tubular damage in early RA is associated with TNF-α expression, especially in the patients with TNF-α above 250 pg/mL, when microalbuminuria rates were significantly higher (p=0.00043). We identified robust data that in the early RA patients with high TNF-α, the number of reported cases of microalbuminuria was significantly higher than in those with low levels.

New developments in transplant proteomics.

PURPOSE OF REVIEW: Despite modern immunosuppression, renal allograft rejection remains a major contributor to graft loss. Novel biomarkers may help improve posttransplant outcomes through the early detection and treatment of rejection. Our objective is to provide an overview of proteomics, review recent discovery-based rejection studies, and explore innovative approaches in biomarker development. RECENT FINDINGS: Urine MMP7 was identified as a biomarker of subclinical and clinical rejection using two-dimensional liquid chromatography tandem-mass spectrometry (LC-MS/MS) and improved the overall diagnostic discrimination of urine CXCL10 : Cr alone for renal allograft inflammation. A novel peptide signature to classify stable allografts from acute rejection, chronic allograft injury, and polyoma virus (BKV) nephropathy was identified using isobaric tag for relative and absolute quantitation (TRAQ) and label-free MS, with independent validation by selected reaction monitoring mass spectrometry (SRM-MS). Finally, an in-depth exploration of peripheral blood mononuclear cells identified differential proteoform expression in healthy transplants versus rejection. SUMMARY: There is still much in the human proteome that remains to be explored, and further integration of renal, urinary, and exosomal data may offer deeper insight into the pathophysiology of rejection. Functional proteomics may be more biologically relevant than protein/peptide quantity alone, such as assessment of proteoforms or activity-based protein profiling. Discovery-based studies have identified potential biomarker candidates, but external validation studies are required.

Clinical outcomes in children with Henoch-Schönlein purpura nephritis without crescents.

BACKGROUND: Henoch-Schönlein purpura is the most common vasculitis in children. Its long-term prognosis depends on renal involvement. The management of Henoch-Schönlein purpura nephritis (HSPN) remains controversial. This study reports the prognosis of children with HSPN presenting with class 2 International Study of Kidney Disease in Children (ISKDC) nephritis. METHODS: All children with HSPN class 2 diagnosed between 1995 and 2015 in four pediatric nephrology centers were included, and clinical and biological data were collected from the medical files. The primary endpoint was proteinuria remission defined as a proteinuria <200 mg/L. RESULTS: Ninety-two children were included in the study with a median follow-up of 36 (6-120) months; 28% had nephrotic syndrome, 31% proteinuria >3 g/L, 52% proteinuria between 1 and 3 g/L, and 18% proteinuria <1 g/L. Forty-seven percent of patients received orally treatment with steroids alone, 37% received methylprednisolone pulses followed by steroids orally, 18% received no steroids. Although 85% reached remission during follow-up, 12% did not maintain complete remission over time so that only 75% remained in complete remission by the end of the follow-up. Univariate analysis found a higher likelihood of remission in patients with higher proteinuria at disease onset (p = 0.009). This trend was not found in the multivariate analysis after adjusting for treatments, as patients with higher proteinuria were most often treated with steroids. CONCLUSION: Our study shows that one fourth of patients with HSPN class 2 remain proteinuric and thus carry the risk of developing chronic kidney disease over the long term. This finding, together with the better outcome of patients treated with steroids, is in favor of using high-dose steroids orally or IV in these patients.

The ISKDC classification and a new semiquantitative classification for predicting outcomes of Henoch-Schönlein purpura nephritis.

BACKGROUND: Histological findings from primary kidney biopsies were correlated with patient outcomes in a national cohort of paediatric Henoch-Schönlein nephritis (HSN) patients. METHODS: Primary kidney biopsies from 53 HSN patients were re-evaluated using the ISKDC (International Study of Kidney Disease in Children) classification and a modified semiquantitative classification (SQC) that scores renal findings and also takes into account activity, chronicity and tubulointerstitial indices. The ISKDC and SQC classifications were evaluated comparatively in four outcome groups: no signs of renal disease (outcome A, n = 27), minor urinary abnormalities (outcome B, n = 18), active renal disease (outcome C, n = 3) and renal insufficiency, end-stage renal disease or succumbed due to HSN (outcome D, n = 5). For the receiver operating characteristic and logistic regression analyses, outcomes A and B were considered to be favourable and outcomes C and D to be unfavourable. The median follow-up time was 7.3 years. RESULTS: The patients with an unfavourable outcome (C and D), considered together due to low patient numbers, had significantly higher total biopsy SQC scores and activity indices than those who had a favourable one (groups A and B). The chronicity and tubulointerstitial indices differed significantly only between group C + D and group A. The difference in areas under the curve between the total biopsy SQC scores and ISKDC findings was 0.15 [p = 0.04, normal-based 95% confidence interval (CI) 0.007-0.29, bias-controlled 95% CI -0.004 to 0.28]. CONCLUSIONS: Our results suggest that the modified SQC is more sensitive than ISKDC classification for predicting the outcome in HSN cases.

Urinary Macrophage Migration Inhibitory Factor as a Noninvasive Biomarker in Pediatric Henoch-Schönlein Purpura Nephritis.

PURPOSES: The aims of this study were to investigate urinary macrophage migration inhibitory factor (MIF) levels and their clinical significance in Henoch-Schönlein purpura (HSP) children with or without nephritis (N) and to assess the influence of steroid treatment on the urine MIF levels of HSPN patients. METHODS: Group I comprised 35 children with HSPN who were examined twice (A before treatment and B after steroid treatment). Group II comprised 41 children with HSP. The control group included 32 healthy children. Urinary MIF levels were measured via enzyme linked immunosorbent assay. The levels of serum creatinine, blood urea nitrogen, urinary microalbumin (mAlb), and 24-hour proteinuria were performed to determine their associations with MIF levels. RESULTS: Urinary MIF levels were significantly higher in group I compared with group II and the control group (P < 0.01); however, no significant difference was found between group II and the control group (P > 0.05). Upon examination, albeit urinary MIF concentration was significantly lower in group IB compared with group IA (P < 0.05), these concentrations were statistically higher than that of group II (P < 0.05). In addition, in the HSPN patients, the urinary MIF was positively associated with urinary microalbumin and 24-hour proteinuria but no association with serum creatinine and blood urea nitrogen. CONCLUSIONS: Elevated urinary MIF levels were found to be correlated with proteinuria in pediatric HSPN. An obvious decrease in urinary MIF concentrations among the children with HSPN was associated with steroid treatment. Urinary MIF can be used as a noninvasive biomarker in pediatric HSPN.

Mining the human urine proteome for monitoring renal transplant injury.

The human urinary proteome provides an assessment of kidney injury with specific biomarkers for different kidney injury phenotypes. In an effort to fully map and decipher changes in the urine proteome and peptidome after kidney transplantation, renal allograft biopsy matched urine samples were collected from 396 kidney transplant recipients. Centralized and blinded histology data from paired graft biopsies was used to classify urine samples into diagnostic categories of acute rejection, chronic allograft nephropathy, BK virus nephritis, and stable graft. A total of 245 urine samples were analyzed by liquid chromatography-mass spectrometry using isobaric Tags for Relative and Absolute Quantitation (iTRAQ) reagents. From a group of over 900 proteins identified in transplant injury, a set of 131 peptides were assessed by selected reaction monitoring for their significance in accurately segregating organ injury causation and pathology in an independent cohort of 151 urine samples. Ultimately, a minimal set of 35 proteins were identified for their ability to segregate the 3 major transplant injury clinical groups, comprising the final panel of 11 urinary peptides for acute rejection (93% area under the curve [AUC]), 12 urinary peptides for chronic allograft nephropathy (99% AUC), and 12 urinary peptides for BK virus nephritis (83% AUC). Thus, urinary proteome discovery and targeted validation can identify urine protein panels for rapid and noninvasive differentiation of different causes of kidney transplant injury, without the requirement of an invasive biopsy.

Blood and Urinary Abnormalities Induced During and After 24-Hour Continuous Running: A Case Report.

In this reported clinical case, a healthy and well-trained male subject [aged 37 years, maximal oxygen uptake (V[Combining Dot Above]O2max) 64 mL·kg·min] ran for 23 hours and 35 minutes covering 160 km (6.7 km/h average running speed). The analysis of hematological and biochemical parameters 3 days before the event, just after termination of exercise, and after 24 and 48 hours of recovery revealed important changes on muscle and liver function, and hemolysis. The analysis of urine sediments showed an increment of red and white blood cells filtrations, compatible with transient nephritis. After 48 hours, most of these alterations were recovered. Physicians and health professionals who monitor such athletic events should be aware that these athletes could exhibit transient symptoms compatible with severe pathologies and diseases, although the genesis of these blood and urinary abnormalities are attributable to transient physiological adaptations rather to pathological status.

Urinary MCP-1/creatinine in Henoch-Schönlein purpura and its relationship with nephritis.

BACKGROUND: Monocyte chemotactic protein-1 (MCP-1) plays a direct role in the infiltration of macrophages and monocytes during the early stages of Henoch-Schönlein purpura (HSP) nephritis. The aim of this study was to compare the urinary MCP-1/creatinine levels in children with and without HSP nephritis and determine if they are associated with the severity of renal lesions. METHODS: We included 77 patients with HSP and 25 healthy control children. Levels of serum creatinine, urinalysis, and 12-h proteinuria assessments were performed. Urinary MCP-1 levels were determined by ELISA. RESULTS: Fifty-seven patients had nephritis (74 %). Urinary MCP-1/creatinine levels were significantly higher in patients with HSP nephritis (median, 653 pg/mg) compared to those with HSP without nephritis (median, 269 pg/mg) or healthy children (191 pg/mg). In addition, higher MCP-1/creatinine levels were observed in HSP patients who had renal biopsy (median, 1,412 pg/mg) in comparison to HSP patients without renal biopsy (median, 302 pg/mg). The urinary MCP-1 cut-off value of 530 pg/mg could be used to distinguish patients who undergo renal biopsy with a sensitivity of 81 % and specificity of 77 %. CONCLUSIONS: Urinary MCP-1/creatinine levels are elevated in the early stages of severe HSP nephritis and can be used as a biomarker for HSP nephritis.

Pseudonephritis is associated with high urinary osmolality and high specific gravity in adolescent soccer players.

The study aimed to evaluate the effect of exercise on urine sediment in adolescent soccer players. In 25 15-year-old (range 14.4-15.8 yrs) athletes, urinary protein, osmolality and cytology were analyzed by flow cytometry and automated dipstick analysis before (T(0)), during (T(1)), and after a match (T(2)). All athletes had normal urine analysis and blood pressure at rest, tested before the start of the soccer season. Fifty-eight samples were collected (T(0): 20, T(1): 17, T(2): 21). Proteinuria was present in 20 of 38 samples collected after exercise. Proteinuria was associated with increased urinary osmolality (p < .001) and specific gravity (p < .001). Hyaline and granular casts were present in respectively 8 of 38 and 8 of 38 of the urinary samples after exercise. The presence of casts was associated with urine protein concentration, osmolality, and specific gravity. This was also the case for hematuria (25 of 38) and leucocyturia (9 of 38). Squamous epithelial cells were excreted in equal amounts to white and red blood cells. A notable proportion of adolescent athletes developed sediment abnormalities, which were associated with urinary osmolality and specific gravity.

Urinary neutrophil gelatinase-associated lipocalin is a potential biomarker for renal damage in patients with systemic lupus erythematosus.

Neutrophil gelatinase-associated lipocalin (NGAL) has been demonstrated to be a novel biomarker in acute and chronic kidney disease. We hypothesized that 24-hour urinary NGAL excretion may be a predictor for renal damage in patients with systemic lupus erythematosus (SLE). Thirty-four SLE patients with renal involvement (SLE-renal group), 8 SLE patients without renal involvement (SLE-nonrenal group), 14 patients with non-SLE autoimmune diseases (disease control or DC group), and 12 healthy volunteers (normal control or NC group) were compared for 24-hour urinary excretion of NGAL and different cytokines. We found that the 24-hour urinary NGAL excretion in the SLE-renal group was higher than that in the SLE-non-renal, DC, and NC groups. However, the excretion of interleukin-10, transforming growth factor-ß1, and tumor necrosis factor-α was not different between the SLE-renal and SLE-non-renal groups. Furthermore, NGAL excretion in the SLE-renal group was correlated with serum creatinine levels and creatinine clearance, but not with the SLE Disease Activity Index score. Multivariate logistic regression analysis and receiver operating characteristic curve analysis revealed that 24-hour urinary NGAL excretion is a potential biomarker for renal damage in SLE patients, with higher sensitivity and specificity than anti-dsDNA antibody titers.

Outcome of Henoch-Schönlein purpura 8 years after treatment with a placebo or prednisone at disease onset.

BACKGROUND: Corticosteroids have been shown not to prevent the development of Henoch-Schönlein nephritis. However, long-term follow-up data are scarce. METHODS: The long-term outcome of patients in a randomized placebo-controlled prednisone study was evaluated 8 years later with a health questionnaire completed by 160/171 (94%) patients and by urine and blood pressure screening (138/171, 81%). RESULTS: Twelve patients had hematuria and/or proteinuria and seven had hypertension. The patients with nephritis at onset of Henoch-Schönlein purpura (HSP) had an increased risk of hypertension and/or urine abnormalities (odds ratio 3.6, p = 0.022, 95% confidence interval 1.3-10.0). There were no differences between the prednisone and placebo groups. Recurrences of purpura were reported by 15 patients, with some recurrences continuing for 10 years. All five reported pregnancies were complicated by proteinuria. Four patients presented with hematuria and/or proteinuria at the control visit, and four had hypertension. Of these, two had a decreased estimated glomerular filtration rate. CONCLUSIONS: HSP has a good long-term prognosis in unselected patients, although skin relapses with/without late-onset nephritis may occur, even a decade after the initial disease. Urine and blood pressure abnormalities 8 years after HSP are associated with nephritis at its onset. Early prednisone treatment does not affect the outcome and should not be routinely used.

Lipoxins as biomarkers of lupus and other inflammatory conditions.

Inflammatory events persist in systemic lupus erythematosus (lupus) despite the use of anti-inflammatory (both steroidal and non-steroidal) and immunosuppressive drugs leading to delay in the healing/repair process and so tissue/organ damage continues. The continuation of inflammation in lupus could be attributed to failure of the resolution process due to deficiency of potent endogenous pro-resolution-inducing molecules such as lipoxin A4 (LXA4). It is likely that progression and flares of lupus and lupus nephritis are due to decreased formation and release of LXA4. Hence, administration of LXA4 and its analogues could be of benefit in lupus. Furthermore, plasma and urinary measurement of lipoxins may be used to predict prognosis and response to therapy. It is likely that lipoxins and other bioactive anti-inflammatory lipids such as resolvins, protectins, maresins and nitrolipids play a significant role in other auto-immune diseases such as rheumatoid arthritis, type 1 diabetes mellitus and multiple sclerosis and hence, could be of significant benefit in these diseases.

Cut-off values for serum matrix metalloproteinase-9: is there a threshold to predict renal involvement for Henoch-Schonlein purpura in children?

AIM: To clarify whether the level of matrix metalloproteinase-9 (MMP-9), tissue inhibitor matrix metalloproteinase-1 (TIMP-1) or the ratio of MMP-9/TIMP-1 was associated with the renal involvement in Henoch-Schonlein purpura (HSP); and to explore whether there existed early diagnostic measure for HSP nephritis (HSPN). METHODS: Sixty-six patients with HSPN, 68 patients with HSP and 60 healthy children (control group) were enrolled into our study. Serum and urine samples before treatment were collected for detection. RESULTS: Compared with the HSP group and control group, serum MMP-9, TIMP-1 and ratio of MMP-9/TIMP-1 in the HSPN group were significantly higher (P<0.05 and P<0.01, respectively). Urine MMP-9, TIMP-1 and ratio of MMP-9/TIMP-1 in the HSPN group were obviously higher than those of the control group (P<0.05) and the HSP group (P<0.05). Receiver-operator curve (ROC) analysis was performed to obtain the area under the curve (AUC) and the AUC and its 95% confidence interval (CI) of serum MMP-9 were 0.97 and 0.95-0.99, respectively. The optimal cut-off point (sensitivity; specificity) of serum MMP-9 for diagnosing HSPN was 179.79 mg/L (0.96; 0.88). CONCLUSION: Levels of MMP-9, TIMP-1 and ratio of MMP-9/TIMP-1 in serum and urine were remarkably high in the patients with HSPN, but the serum MMP-9 was more sensitive. Serum MMP-9 may be associated with the occurrence and development of renal involvement in HSPN and become an important indicator for early diagnosis of HSPN.