Long-term prognosis of IgA nephropathy presenting with minimal or no proteinuria: A single center experience

Spontaneous remission in adult patients with IgA nephropathy treated with conservative therapy

Background

There are few studies describing the clinical course and spontaneous remission of IgA nephropathy (IgAN) in adult patients receiving conservative treatment.

Method

Data from 62 adult patients with biopsy-diagnosed IgAN, who received conservative treatment at least 5 years prior, were retrospectively investigated. No patients received corticosteroids, other immunosuppressants, or tonsillectomy. Remission of proteinuria and hematuria were defined as proteinuria <0.3 g/gCr and urine red blood cells (RBC) <5 / high power field (HPF) on three consecutive urinalyses obtained during an observation period of ≥6 months.

Result

Thirty-eight (61.3%) patients had remission of hematuria, 24 (38.7%) had remission of proteinuria, and 19 (30.6%) had remission of both. Remission rates increased in patients with proteinuria <0.5 g/g Cr at diagnosis. The median time to remission of hematuria was 2.8 years and that of proteinuria was 2.6 years. Patients who showed renal function decline (defined as 30% decline of estimated glomerular filtration rate [eGFR] from baseline) were older, had significantly lower eGFR, and higher proteinuria at diagnosis. Two patients with preserved renal function and normal proteinuria at diagnosis experienced renal function decline. Renal function did not decline within 3 years of diagnosis in patients with proteinuria <1 g/gCr at diagnosis.

Conclusions

Relatively high rates of spontaneous remission were observed. Remission of both hematuria and proteinuria were frequent within 3 years after diagnosis, and renal function was well preserved during this period. These data indicate that it is rational to use conservative treatment for 3 years after the diagnosis instead of aggressive treatments.

Enumerating the role of properdin in the pathogenesis of IgA nephropathy and its possible therapies

BACKGROUND

IgA nephropathy (IgAN) has become the most prevalent form of glomerulonephritis affecting almost 1.3% of the total population worldwide. It is an autoimmune disorder where the host autoantibody forms an immune complex with the defective galactose-deficient IgA1 and gets deposited at the mesangium and endocapillary region of glomeruli. IgA has the capability to activate alternative and lectin complement cascades which even aggravates the condition. Properdin is directly associated with IgAN by activating and stabilising the alternative complement pathway at the mesangium, thereby causing progressive renal damage.

OBJECTIVE

The present review mainly focuses on correlating the influence of properdin in activating the complement cascade at glomeruli which is the major cause of disease exacerbation. Secondly, we have described the probable therapies and new targets that are under trials to check their efficacy in IgAN.

METHODS

An in-depth research was carried out from different peer-reviewed articles till December 2020 from several renowned databases like PubMed, Frontier, and MEDLINE, and the information was analysed and written in a simplified manner.

RESULTS

Co-deposition of properdin is observed along with IgA and C3 in 75%-100% of the patients. It is not yet fully understood whether properdin inhibition can attenuate IgAN, as many conflicting reports have revealed worsening of IgAN after impeding properdin.

CONCLUSION

With no specific cure still available, the treatment strategies are of great concern to find a better target to restrict the disease progression. More research and clinical trials are required to find out a prominent target to combat IgAN.

Efficacy and Safety of Renin-Angiotensin Aldosterone System Inhibitor in Patients with IgA Nephropathy: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) as the commonly used renin-angiotensin aldosterone system inhibitor are widely used in patients with IgA nephropathy (IgAN), but the effect is controversy. In this study, we used a meta-analysis to evaluate the efficacy and safety of ACEI and/or ARB for the patients with IgAN.

METHODS

Two investigators independently searched the PubMed, EMBASE, the Cochrane Library, EBSCO, and Wiley databases without language restrictions. We collected the clinical randomized controlled trials (RCTs) on "ACEI and/or ARB for the patients with IgAN" published before December 31, 2018, and performed data extraction and quality analysis on the included studies, and analyzed data using RevMan 5.2 software.

RESULTS

A total of 10 RCTs (635 patients) were included in our analysis. Alone use of ACEI (MD=-0.75, 95%CI: -1.28-0.21, P=0.006) or ARB (MD=-0.56, 95%CI: -0.82-0.30, P< 0.001) or a combination of ACEI and ARB (MD=-0.63, 95%CI: -0.87-0.38, P<0.001) significantly reduced the levels of proteinuria in patients with IgAN. However, whether using ACEI or ARB alone or in combination with ACEI and ARB, there was no significant effect on serum creatinine, 24-creatinine clearance and glomerular filtration rate in patients with IgAN.

CONCLUSION

The use of ACEI and ARB significantly reduces the levels of proteinuria in patients with IgAN, but more large-sample RCTs with long-term follow-up are needed for confirming our results and guiding clinical treatment.