Effect of hematuria on the outcome of IgA nephropathy with mild proteinuria

Microscopic hematuria as a risk factor for IgAN progression: considering this biomarker in selecting and monitoring patients

Hematuria-either macroscopic hematuria or asymptomatic microscopic hematuria-is a clinical feature typical but not specific for immunoglobulin A nephropathy (IgAN). The only biomarker supported by the Kidney Disease: Improving Global Outcomes group as a predictor of progression, identifying patients needing treatment, is proteinuria >1 g/day persistent despite maximized supportive care. However, proteinuria can occur in the setting of active glomerulonephritis or secondary to sclerotic renal lesions. Microscopic hematuria is observed in experimental models of IgAN after IgA-IgG immunocomplex deposition, activation of inflammation and complement pathways. Oxidative damage, triggered by hemoglobin release, is thought to contribute to the development of proteinuria and progression. Despite being a clinical hallmark of IgAN and having a rational relationship with its pathophysiology, the value of microscopic hematuria in assessing activity and predicting outcomes in patients with IgAN is still debated. This was partly due to a lack of standardization and day-to-day variability of microhematuria, which discouraged the inclusion of microhematuria in large multicenter studies. More recently, several studies from Asia, Europe and the USA have highlighted the importance of microhematuria assessment over longitudinal follow-up, using a systematic approach with either experienced personnel or automated techniques. We report lights and shadows of microhematuria evaluation in IgAN, looking for evidence for a more consistent consensus on its value as a marker of clinical and histological activity, risk assessment and prediction of treatment response. We propose that hematuria should be included as part of the clinical decision-making process when considering when to use immunosuppressive therapy and as part of criteria for enrollment into clinical trials to test drugs targeting the inflammatory reaction elicited by immune pathway activation in IgAN.

Effect of hematuria on the kidney disease progression in IgA nephropathy patients with mild proteinuria and well-preserved renal function

OBJECTIVE

To investigate whether hematuria is a risk factor in IgA nephropathy (IgAN) patients with mild proteinuria and well-preserved renal function.

METHODS

This retrospective study included a total of 63 IgAN patients, with complete clinical data available for 50 patients. Hematuria assessment was conducted using two methods: 1) an automated method using a urine particle analyzer, and 2) a manual method performed by a skilled examiner to examine microscopic urine sediment.

RESULTS

The results of hematuria measurement using both automated and manual methods showed a strong linear correlation (r = 0.78, P < 0.001). In IgAN patients, those with high urinary red blood cell count (U-RBCs) exhibited higher serum IgA levels compared to patients with low U-RBCs. Additionally, patients with crescent formation had higher levels of proteinuria compared to those without crescents. Patients who received immunosuppressive treatment displayed higher levels of systolic blood pressure (SBP) and mean arterial pressure (MAP), as well as lower levels of serum hemoglobin and albumin. They also had a higher prevalence of T1 lesions compared to patients who did not undergo immunosuppression. Furthermore, among patients with crescent formation, those who received immunosuppressive agents exhibited higher levels of SBP, diastolic blood pressure (DBP), MAP, and U-RBCs, as well as lower levels of albumin and proteinuria at the time of renal biopsy. No composite kidney endpoint events were observed in these groups of patients. The U-RBCs level was not identified as a risk factor influencing the decline of estimated glomerular filtration rate (eGFR) in IgAN.

CONCLUSIONS

The presence of hematuria at the time of biopsy was not found to be associated with kidney disease progression in IgAN patients who had mild proteinuria and well-preserved renal function. This suggests that it is possible that these patients may not derive significant benefits from immunosuppressive therapy.

Podocytes are likely the therapeutic target of IgA nephropathy with isolated hematuria: Evidence from repeat renal biopsy

Background: The present study aimed to prove the progression of immunoglobulin A nephropathy (IgAN) patients with isolated hematuria based on repeat renal biopsy data for the first time. Methods: 29 IgAN patients with isolated hematuria who received repeat renal biopsies were analyzed retrospectively, while 29 non-isolated hematuria IgAN patients with similar age and background were randomly selected as the control group. Clinical parameters were collected at the time of biopsy. The treatment strategies (conservative treatment with RASS blocker or immunosuppressive treatment) were choosen according to the pathological results at the first renal biopsy. The activity and chronicity indexes of renal lesions were evaluated. Markers of cell inflammation and proliferation were tseted by immunochemistry. The ultrastructure of podocytes was observed by transmission electron microscopy (TEM). Podocyte and oxidative stress marker (NPHS2 and 4-HNE) were detected by immunofluorescence. Results: The IgAN patients with isolated hematuria had better clinical indicators than those with no-isolated hematuria, such as better renal function, higher albumin and lower uric acid. The interval between two biopsies in IgAN patients with isolated hematuria was 630 (interquartile range, 409.5-1,171) days. The hematuria of the patients decreased significantly from 30 (IQR, 4.00-35.00) RBC/ul in the first biopsy to 11 (IQR, 2.50-30.00) RBC/ul in the repeated biopsy (p < 0.05). The level of triglyceride decreased significantly (p < 0.05). The other clinical indicators were not statistically significant (p > 0.05). Deposits of IgA and C3 in the glomerulus were persistent. The activity index decreased, especially cellular crescent formation, while the chronicity index increased. The ultrastructure of podocytes was improved after treatment. The oxidative stress products of podocytes reduced after treatment. Conclusion: Although the clinical indicators of the IgAN patients with isolated hematuria were in the normal range, various acute and chronic pathological changes have occurred, and irreversible chronic changes have been progressing. Cell inflammation and proliferation persisted. Oxidative stress of podocytes was likely to be the therapeutic target. This study provided a strong basis for the progress of IgAN with isolated hematuria through pathological changes before and after treatment. This study will help clinicians recognize the harm of hematuria, change the traditional treatment concept, and help such patients get early treatment.

Time-Averaged Hematuria as a Prognostic Indicator of Renal Outcome in Patients with IgA Nephropathy

We aim to investigate the association of time-averaged hematuria (TA-hematuria) with the progression of IgA nephropathy (IgAN). Based on TA-hematuria during follow-up, 152 patients with IgAN were divided into a hematuria remission group (≤28 red blood cells [RBCs]/μL) and a persistent hematuria group (>28 RBCs/μL). The persistent hematuria group had a higher percentage of patients with macroscopic hematuria, lower levels of hemoglobin and TA-serum albumin, and more severe renal pathologic lesions. The composite endpoint is defined as a doubling of the baseline SCr level (D-SCr), or the presence of ESRD. During the mean follow-up of 58.08 ± 23.51 months, 15 patients (9.9%) reached the primary outcome of ESRD and 19 patients (12.5%) reached the combined renal endpoint. Kaplan-Meier analysis showed that the persistent hematuria group had a lower renal survival rate. The persistent hematuria patients who were incorporated with proteinuria (≥1.0 g/day) and low TA-serum albumin (<40 g/L) had the worst renal outcomes. Multivariate Cox regression indicated that TA-hematuria (hazard ratio [HR] = 0.004, 95% CI: 0.001, 0.008; p = 0.010) was independently associated with the progression of IgAN. Receiver operating characteristic analysis indicated the optimal TA-hematuria cutoff value for predicting the progression of IgAN was 201.21 RBCs/μL in females and 37.25 RBCs/μL in males.

Long-Term Outcomes of Patients with IgA Nephropathy Categorized by the International IgAN Risk Prediction Tool and by the Degree of Hematuria at Diagnosis

INTRODUCTION

Within 30 years, 20-50% of IgA nephropathy (IgAN) patients progress to end-stage kidney disease (ESKD). Identifying these patients can be difficult since renal function may deteriorate after being stable for years. The International IgAN Risk Prediction tool (IgAN-RPT) combines histologic lesions and clinical risk factors to predict renal outcome up to 5 or 7 years of follow-up. The clinical value beyond 7 years is unknown and microhematuria data has not been assessed.

METHODS

We studied the long-term renal outcome of 95 Swedish IgAN patients from the derivation cohort for the IgAN-RPT. The median follow-up was 11.2 years. Microhematuria at baseline was defined as high-degree by microscopy measurement of >10 red blood cell/high-power field of view or urine dipstick grading of 2-3. Primary outcome was defined as a 50% decrease in estimated glomerular filtration rate or ESKD.

RESULTS

The mean predicted 5-year risk for increasing quartiles was 0.95%, 2.57%, 5.88%, and 23.31% and the observed 5-year-outcome was 0%, 0%, 0%, and 33.33%. During continued follow-up, 0%, 4.2%, 21.7%, and 75.0% of patients reached the primary outcome. ROC curve analysis identified the 5-year risk thresholds of under 4% and over 11% for very low and very high-risk patients, respectively. High-degree microhematuria was not significantly associated with renal outcome (p = 0.14).

CONCLUSIONS

The IgAN-RPT identifies long-term high- and low-risk patients, which can guide decisions on the frequency of clinical control visits and the selection of patients for clinical trials. Patients with intermediate risk remain a clinical challenge with an urgent need for novel biomarkers and treatments. Microhematuria could be a valuable marker of inflammatory activity, but measurement needs to be standardized for implementation in risk prediction tools.

The association of microhematuria with mesangial hypercellularity, endocapillary hypercellularity, crescent score and renal outcomes in immunoglobulin A nephropathy

BACKGROUND

Microhematuria is common in immunoglobulin A nephropathy (IgAN). However, current prognostication is based on proteinuria and mesangial hypercellularity, endocapillary hypercellularity, segmental sclerosis, tubulointerstitial fibrosis and crescent (MEST-C) scores.

METHODS

In this retrospective study, we evaluated whether MEST-C score components are associated with the presence of microhematuria at biopsy and whether the degree of microhematuria during follow-up is associated with change in estimated glomerular filtration rate (eGFR), after adjusting for clinical and histological parameters. We identified 125 patients with biopsy-proven IgAN and MEST-C scoring who were not on immunosuppressive therapy at biopsy. Microhematuria was defined as ≥3 red blood cells (RBCs)/high-power field (hpf).

RESULTS

Of the 125 patients, 97 had microhematuria at baseline and were more likely to have M1, E1 and C ≥ 1 lesions (P < 0.05 for all) compared with patients without microhematuria. Of the 125 patients, 72 had follow-up data available. An increase in the degree of microhematuria was significantly associated with an eGFR decline of -0.81 mL/min/1.73 m2 [95% confidence interval (CI) -1.44 to -0.19, P = 0.01], after adjusting for follow-up time, proteinuria and T score. Severe microhematuria (≥21 RBCs/hpf) was associated with an even larger decline in eGFR (-3.99 mL/min/1.73 m2; 95% CI -6.9411 to -1.0552, P = 0.008), after similar adjustments.

CONCLUSION

Degree of microhematuria during follow-up is an independent predictor of eGFR decline after adjusting for clinical and histological parameters. Therefore, monitoring the degree of microhematuria as well as proteinuria is important when evaluating patients with IgAN. Additional studies using improvement in microhematuria as a primary surrogate outcome are needed.

Utility of remission criteria for the renal prognosis of IgA nephropathy

Background

Novel criteria for the remission of Immunoglobulin A nephropathy (IgAN) based on an opinion survey of Japanese nephrologists and literature review were proposed in 2013. This single-center, longitudinal retrospective cohort study was conducted to validate this criteria.

Methods

Present study included the IgAN patients diagnosed between 2001 and 2005 in the Juntendo University Hospital. Remission of hematuria was defined as three consecutive dipstick test results of ( −) to ( ±) or a red blood cell count < 5 in urinary sediment per high-power field during at least 6 months. Remission of proteinuria was defined as three consecutive dipstick results of ( −) to ( ±) during at least 6 months. We categorized four groups according to the remission status which was assessed 2 years after the renal biopsy. The primary outcome was a 50% increase in the serum creatinine over the baseline. We evaluated the slope of eGFR decline (mL/min/1.73 m²/year) and a decrease in the eGFR of 30% from baseline eGFR as the secondary outcome, respectively.

Results

A total of 74 patients (male: 47.3%, median age: 30 years) were included and were followed for a median of 86.5 months. During the period, forty-one patients achieved neither remission of proteinuria nor hematuria (NR). Twelve patients met the primary study outcome. A survival analysis revealed that the NR had the worst prognosis and the steepest slope of eGFR decline.

Conclusion

Although further validation in a large cohort is necessary, these novel remission criteria for IgAN patients appear to predict the renal prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-021-02069-w.

Hematuria was a high risk for renal progression and ESRD in immunoglobulin a nephropathy: a systematic review and meta-analysis

Background: The relationship between hematuria, a typical presentation of immunoglobulin A nephropathy (IgAN), and long-term adverse prognosis of these patients is still controversial. This meta-analysis aims to clarify the effect of hematuria on renal outcomes in IgAN.

Methods: Observational cohort studies reporting associations between various forms of hematuria and renal outcomes among IgAN patients were identified from the PubMed and Embase databases. The pooled adjusted risk ratios (RRs) were computed with random effects models.

Results: Thirteen studies encompassing 5660 patients with IgAN were included. Patients with initial hematuria did not have a significantly increased risk of developing end-stage renal disease (ESRD) compared with those without hematuria (RR, 1.32; 95% CI, 0.87–2.00; p = .19). However, initial microscopic hematuria was associated with an 87% increase in the risk of ESRD (RR, 1.87; 95% CI, 1.40–2.50; p < .001), while macroscopic hematuria was associated with a 32% decrease in the risk of ESRD (RR, 0.68; 95% CI, 0.58–0.79; p < .001). Additionally, persistent hematuria might be an independent risk factor for ESRD or a 50% decline in eGFR.

Conclusions: Among IgAN patients, hematuria, including initial microscopic hematuria and even persistent hematuria, was possibly associated with renal progression and ESRD. However, independent of other classical predictors, initial macroscopic hematuria might be a protective factor for IgAN.

Association of dipstick hematuria with all-cause mortality in the general population: results from the specific health check and guidance program in Japan

Background

Dipstick urine tests are used for general health screening in Japan. The effects of this screening on mortality have not been examined, especially with regard to hematuria.

Methods

Subjects were those who participated in the 2008 Tokutei-Kenshin (nationwide specific health check and guidance program) in six districts in Japan. Using the national database of death certificates from 2008 to 2012, we identified subjects who might have died. We verified the candidates in collaboration with the regional National Health Insurance agency and public health nurses. Data were released to the research team supported by the Ministry of Health, Labor, and Welfare of Japan. Dipstick results of 1+ and higher were defined as hematuria (+). Hazard ratio (HR) [95% confidence interval (CI)] was calculated using the Cox proportional hazard analysis.

Results

Among 112 115 subjects, we identified that 1290 had died by the end of 2012. In hematuria (-) subjects, the crude mortality rates were 1.2% (1.8% in men, 0.7% in women), whereas in hematuria (+) subjects, they were 1.1% (2.9% in men, 0.7% in women). After adjusting for age, body mass index, estimated glomerular filtration rate, proteinuria, comorbid condition (diabetes mellitus, hypertension and dyslipidemia), past history (stroke, heart disease and kidney disease) and lifestyle (smoking, drinking, walking and exercise), the HR (95% CI) for dipstick hematuria (+) in men was 1.464 (1.147-1.846; P = 0.003), whereas that for hematuria (-) was 0.820 (0.617-1.073; P = 0.151).

Conclusions

Dipstick hematuria is significantly associated with mortality in men among Japanese community-based screening participants.

Inker L, Floege J, Perkovic V, Boyer-Suavet S, W. Major R, I. Schimpf J, Barratt J, Cattran DC, S. Gillespie B, Kausz A, W. Mercer A, Reich HN, H. Rovin B, West M, Nachman PH. Proteinuria Reduction as a Surrogate End Point in Trials of IgA Nephropathy

IgA nephropathy (IgAN) is an important cause of ESKD for which there are no approved therapies. A challenge for evaluating treatments for IgAN is the usual long time course for progression to ESKD. The aim of this Kidney Health Initiative project was to identify surrogate end points that could serve as reliable predictors of a treatment's effect on long-term kidney outcomes in IgAN and be used as a basis for approval. Proteinuria was identified as the most widely recognized and well studied risk factor for progression to ESKD in IgAN. The workgroup performed a critical review of the data on proteinuria reduction as a surrogate end point for a treatment's effect on progression to ESKD in IgAN. Epidemiologic data indicate a strong and consistent relationship between the level and duration of proteinuria and loss of kidney function. Trial-level analyses of data from 13 controlled trials also show an association between treatment effects on percent reduction of proteinuria and treatment effects on a composite of time to doubling of serum creatinine, ESKD, or death. We conclude that data support the use of proteinuria reduction as a reasonably likely surrogate end point for a treatment's effect on progression to ESKD in IgAN. In the United States, reasonably likely surrogate end points can be used as a basis for accelerated approval of therapies intended to treat serious or life-threatening conditions, such as IgAN. The clinical benefit of products approved under this program would need to be verified in a postmarketing confirmatory trial.

Gender-related differences in clinicopathological characteristics and renal outcomes of Chinese patients with IgA nephropathy

Background

The prognostic effect of gender on immunoglobulin A nephropathy (IgAN) is not clear. We explored gender-related differences in clinicopathological features and renal outcomes in IgAN.

Methods

This was a single-centre retrospective study. Patients were divided into two groups according to gender. The clinicopathological features at biopsy and renal outcomes during the follow-up were collected and analysed. Renal outcomes were defined as the doubling of baseline serum creatinine and end-stage renal disease (ESRD) (estimated glomerular filtration rate < 15 mL/min/1.73 m², dialysis, or renal transplantation). The prognostic effects of gender were evaluated by Cox regression models.

Results

A total of 988 eligible IgAN patients were enrolled, and the ratio of males to females was 1:1.4. Compared with female patients, male patients had worse renal function, greater proteinuria, a higher prevalence of hypertension, hypertriglyceridaemia and hyperuricaemia, and more severe segmental sclerosis and tubular atrophy/interstitial fibrosis. However, haematuria occurred more frequently in female patients. During a median follow-up time of 48.6 (34.7, 62.7) months, no differences in renal survival rates were noted between the male and female groups. Multivariable Cox regression analyses revealed that gender was not a significant risk factor for renal outcomes after frequency matching of baseline eGFR and serum uric acid (SUA) levels. In addition, male and female patients shared similar risk factors, including a low eGFR and increased proteinuria and segmental sclerosis. In males, however, an elevated proportion of global glomerulosclerosis was also a poor prognostic factor for renal survival.

Conclusions

Male IgAN patients presented with worse clinicopathologic features than female patients, but no significant differences were observed in long-term renal survival between male and female patients by eGFR- and SUA level-matching.

Remission of Hematuria Improves Renal Survival in IgA Nephropathy

Hematuria is a cardinal symptom in IgA nephropathy, but its influence on the risk of disease progression has been scarcely investigated. We followed a cohort of 112 patients with IgA nephropathy for a mean±SEM period of 14±10.2 years, during which clinical and analytic risk factors (including urine sediment examination) were regularly recorded. According to the magnitude of time-averaged hematuria, we classified patients as those with persistent hematuria and those with negative or minimal hematuria. We also classified patients according to the magnitude of time-averaged proteinuria (>0.75 or ≤0.75 g/d). The proportion of patients reaching ESRD or a 50% reduction of renal function was significantly greater among patients with persistent hematuria than patients with minimal or negative hematuria (30.4% and 37.0% versus 10.6% and 15.2%, respectively; P=0.01). Multivariable analysis revealed time-averaged hematuria, time-averaged proteinuria, renal function at baseline, and the presence of tubulointerstitial fibrosis on renal biopsy as independent predictors of ESRD. After hematuria disappearance, which occurred in 46% of the patients, the rate of renal function decline changed from -6.45±14.66 to -0.18±2.56 ml/min per 1.73 m² per year (P=0.001). Patients with time-averaged proteinuria >0.75 g/d had significantly poorer renal survival than those with time-averaged proteinuria ≤0.75 g/d. However, on further classification by time-averaged hematuria, only those patients with time-averaged proteinuria >0.75 g/d and persistent hematuria had significantly worse renal survival than those in the other three groups. In conclusion, remission of hematuria may have a significant favorable effect on IgA nephropathy outcomes.

Comparison of methods of steroid administration combined with tonsillectomy for IgA nephropathy patients

BACKGROUND

IgA nephropathy (IgAN) is a chronic glomerular disease that causes end-stage renal disease in 20-40 % of patients within 20 years. The efficacy of tonsillectomy combined with steroid pulse (SP) administration (TSP) for clinical remission of IgAN has been reported. Particularly in Japan, TSP has been performed widely. However, the optimum method for steroid administration in TSP has not been established.

METHODS

We retrospectively compared clinical remission in IgAN patients treated with tonsillectomy combined with two different steroid administration methods: (1) three courses of SP therapy and oral prednisolone administered on alternate days (group 3A; n = 25); and (2) one course of SP therapy and oral prednisolone administered on consecutive days (group 1C; n = 22).

RESULTS

There was no significant difference in the clinical remission rates between the two groups at 12 (48.0 vs. 40.9 %, P = 0.77) and 24 months after starting treatment (68.0 vs. 72.7 %, P = 0.76) and at the final observation (76.0 vs. 81.8 %, P = 0.73). The mean period from starting treatment to remission of hematuria in group 3A was significantly shorter than that in group 1C (5.7 ± 4.4 vs. 9.9 ± 5.9 months, P = 0.03). Dyslipidemic patients treated for the first time with statin after the SP therapy were more present in group 3A at 24 months (P = 0.02).

CONCLUSIONS

In IgAN patients, treatment of group 3A may be effective for inducing rapid remission of hematuria. Further studies are needed to establish an appropriate protocol for TSP.

Effect of hematuria on the outcome of immunoglobulin A nephropathy with proteinuria

BACKGROUND

The relationship between hematuria and histological lesions, the effect of hematuria on response to steroid therapy, and the outcome in patients with immunoglobulin A nephropathy (IgAN) remain undetermined.

OBJECTIVES

The aim of this study was to clarify the effect of hematuria on histological findings, response to steroid treatment, and the outcome in IgA nephropathy.

PATIENTS AND METHODS

Seventy-five patients with IgAN and proteinuria > 1 g/day and treated with prednisolone were divided into two groups: those with low (≤20/high-power field [HPF]) urinary red blood cell (U-RBC) counts (L-RBC group, n=55) and those with high (>20/HPF) U-RBC counts (H-RBC group, n=20). Their clinical and histological characteristics, the relationship between hematuria and histological lesions, renal outcomes, and risk factors for progression were compared.

RESULTS

Except for U-RBC counts, the clinical and histological findings according to the Oxford classification of the two groups were similar. U-RBC counts were not correlated with active histological lesions. Median proteinuria in both groups decreased soon after starting steroid therapy. Median U-RBC also decreased after starting steroids, and it became similar between both groups at 2 years after treatment. The 20-year renal survival rate was also similar between the H-RBC and the L-RBC group (45.2% versus 58.0%, P=0.5577). Multivariate Cox regression analysis showed that the lower estimated glomerular filtration rate (eGFR) was an independent risk factor for progression.

CONCLUSIONS

A higher degree of hematuria at renal biopsy in patients with IgAN was not associated with active pathological lesions, such as cellular and fibro-cellular crescents, resistance to steroid treatment and poor outcome.

Long-term outcome of IgA nephropathy with minimal change disease: a comparison between patients with and without minimal change disease

BACKGROUND

The clinicopathological characteristics, treatment response and long-term outcome of immunoglobulin (Ig)A nephropathy with minimal change disease (MCD-IgAN) are not well defined.

METHODS

Patients with biopsy-proven MCD-IgAN from the Jinling Hospital IgA nephropathy Registry were systematically reviewed and compared with those with IgA nephropathy without minimal change disease (Non-MCD-IgAN).

RESULTS

We compared data of 247 MCD-IgAN patients and 1,121 Non-MCD-IgAN patients. Compared to Non-MCD-IgAN, MCD-IgAN patients were younger,with male predominance, had higher levels of proteinuria, total cholesterol and estimated glomerular filtration rate (eGFR), lower incidence of hypertension and microhematuria, lower level of serum creatinine, and had less severe glomerular, tubulointerstitial and vascular lesions in renal pathology. In the Non-MCD-IgAN group, 157 patients (14.0 %) reached the renal endpoint and 103 patients (9.2 %) entered end-stage renal disease (ESRD). The 5-,10-, 15- and 20-year cumulative renal survival rates from ESRD, calculated by Kaplan-Meier method, were 95.0, 83.0, 72.9 and 65.4 %, respectively. In the MCD-IgAN group, no patients entered ESRD and only 4 (1.6 %) reached the renal endpoint. Patients with MCD-IgAN had a significantly better renal outcome than Non-MCD-IgAN (p < 0.01). At multivariate Cox analysis, proteinuria >1.0 g/day, hypertension, eGFR <60 ml/min/1.73 m(2), hypoproteinemia and hyperuricemia were independent risk factors of renal survival for Non-MCD-IgAN patients [hazard ratio (HR) 3.43, p < 0.001; HR 1.65, p < 0.05; HR 2.61, p < 0.001; HR 2.40, p < 0.001; HR 2.27, p < 0.001, respectively), but not for patients with MCD-IgAN.

CONCLUSIONS

The long-term outcome of patients with MCD-IgAN is significantly better than that of patients with Non-MCD-IgAN.

Haematuria increases progression of advanced proteinuric kidney disease

Background

Haematuria has been traditionally considered as a benign hallmark of some glomerular diseases; however new studies show that haematuria may decrease renal function.

Objective

To determine the influence of haematuria on the rate of chronic kidney disease (CKD) progression in 71 proteinuric patients with advanced CKD (baseline eGFR <30 mL/min) during 12 months of follow-up.

Results

The mean rate of decline in eGFR was higher in patients with both haematuria and proteinuria (haemoproteinuria, HP, n=31) than in patients with proteinuria alone (P patients, n=40) (-3.8±8.9 vs 0.9±9.5 mL/min/1.73m2/year, p<0.05, respectively). The deleterious effect of haematuria on rate of decline in eGFR was observed in patients <65 years (-6.8±9.9 (HP) vs. 0.1±11.7 (P) mL/min/1.73m2/year, p<0.05), but not in patients >65 years (-1.2±6.8 (HP) vs. 1.5±7.7 (P) mL/min/1.73m2/year). Furthermore, the harmful effect of haematuria on eGFR slope was found patients with proteinuria >0.5 g/24 h (-5.8±6.4 (HP) vs. -1.37± 7.9 (P) mL/min/1.73m2/year, p<0.05), whereas no significant differences were found in patients with proteinuria < 0.5 g/24 h (-0.62±7.4 (HP) vs. 3.4±11.1 (P) mL/min/1.73m2/year). Multivariate analysis reported that presence of haematuria was significantly and independently associated with eGFR deterioration after adjusting for traditional risk factors, including age, serum phosphate, mean proteinuria and mean serum PTH (β=-4.316, p=0.025).

Conclusions

The presence of haematuria is closely associated with a faster decrease in renal function in advanced proteinuric CKD patients, especially in younger CKD patients with high proteinuria levels; therefore this high risk subgroup of patients would benefit of intensive medical surveillance and treatment.