Aberrant IgA1 Glycosylation in IgA Nephropathy: A Systematic Review

<div><p>Objective</p><p>Galactose-deficient IgA1 was evaluated in patients with IgA nephropathy(IgAN) and controls in order to determine the predictive value of galactose-deficient IgA1 in cases of IgA nephropathy.</p><p>Methods</p><p>PubMed, EMBASE, Cochrane central register of controlled trials, CNKI, CBM disc, and VIP database were searched to identify eligible studies that evaluated a difference in aberrant IgA1 glycosylation in IgAN patients compared with controls. A meta-analysis was conducted to evaluate the impact of galactose-deficient IgA1(Gd-IgA1) levels in different groups.</p><p>Results</p><p>A total of 22 studies (n = 1657) met inclusion criteria. The mean Newcastle-Ottawa Scale (NOS) score was 7.2 and ranged from 6 to 8. The standard mean difference(SMD) in the meta-analysis of 20 studies of the level of Gd-IgA1 in the serum and/or supernatant of cultured cells was higher in the IgAN group compared with healthy controls as well as in those with other renal diseases (SMD = 1.76, 95% CI = 1.18–2.34, P<0.00001; SMD = 1.05, 95% CI = 0.05–2.04, P = 0.04). The data synthesis suggested that IgAN patients had similar levels of serum Gd-IgA1, with no significant differences, compared with first-degree relatives and Henoch-Schonlein purpura nephritis (HSPN) patients (MD = 0.04, 95% CI = 0.00–0.08, P = 0.05; MD = -46.03, 95% CI = -217.70–125.64, P = 0.60). In addition, the combined MD of 5 studies indicated that there were no significant differences in Gd-IgA1 levels among patients with varying severities of IgAN (MD = 0.02, 95% CI = -0.02–0.05, P = 0.28).</p><p>Conclusions</p><p>The pooled evidence suggests that the level of Gd-IgA1 in the serum or supernatant of cultured cells from peripheral blood or tonsils may be a useful biomarker for predicting IgA nephropathy, though the level of Gd-IgA1 was not significantly associated with disease severity.</p></div

The forest plots of the comparation between IgAN group and control group.

<p>The forest plots of the comparation between IgAN group and control group.</p

The forest plots of the comparation among IgAN group, HSPN group and controls.

<p>The forest plots of the comparation among IgAN group, HSPN group and controls.</p

Data of the included 22 studies.

<p>Data of the included 22 studies.</p

Flow chart of the meta-analysis.

<p>Flow chart of the meta-analysis.</p

The forest plots of comparison among variable grades of IgAN severity.

<p>The forest plots of comparison among variable grades of IgAN severity.</p

The forest plots of IgAN group and other renal disease group.

<p>The forest plots of IgAN group and other renal disease group.</p

Quality assessment of the 22 included studies with the Newcastle-Ottawa Scale (NOS).

<p>Quality assessment of the 22 included studies with the Newcastle-Ottawa Scale (NOS).</p

The funnel plot of the meta-analysis.

<p>The funnel plot of the meta-analysis.</p

The forest plots of IgAN group and first-degree relatives group.

<p>The forest plots of IgAN group and first-degree relatives group.</p