Mortality of IgA Nephropathy Patients: A Single Center Experience over 30 Years

Abstract

Research on the prognosis of IgA nephropathy (IgAN) has focused on renal survival, with little information being available on patient survival. Hence, this investigation aimed to explore long-term patient outcome in IgAN patients. Clinical and pathological characteristics at the time of renal biopsy were reviewed in 1,364 IgAN patients from 1979 to 2008. The outcomes were patient death and end stage renal disease (ESRD) progression. Overall, 71 deaths (5.3%) and 277 cases of ESRD (20.6%) occurred during 13,916 person-years. Ten-, 20-, and 30-year patient survival rates were 96.3%, 91.8%, and 82.7%, respectively. More than 50% patient deaths occurred without ESRD progression. Overall mortality was elevated by 43% from an age/sex-matched general population (GP) (standardized mortality ratio [SMR], 1.43; 95% confidence interval [CI], 1.04–1.92). Men had comparable mortality to GP (SMR, 1.22; 95% CI, 0.82–1.75), but, in women, the mortality rate was double (SMR, 2.17; 95% CI, 1.21–3.57). Patients with renal risk factors such as initial renal dysfunction (estimated glomerular filgration rate <60 ml/min per 1.73m2; SMR, 1.70; 95% CI, 1.13–2.46), systolic blood pressure ≥140 mmHg (SMR, 1.88; 95% CI, 1.19–2.82) or proteinuria ≥1 g/day (SMR, 1.66; 95% CI, 1.16–2.29) had an elevated mortality rate. Patients with preserved renal function, normotension, and proteinuria <1 g/day, however, had a similar mortality rate to GP. When risk stratification was performed by counting the number of major risk factors present at diagnosis, low-risk IgAN patients had a mortality rate equal to that of GP, whereas high-risk patients had a mortality rate higher than that of GP. This investigation demonstrated that overall mortality in IgAN patients was higher than that of GP. Women and patients with renal risk factors had a higher mortality than that of GP, Therefore, strategies optimized to alleviate major renal risk factors are warranted to reduce patient mortality.

Long-Term Survival of Patients with IgA Nephropathy After Dialysis Therapy

“…The 10- and 20-year survival rates of the patients with IgAN after starting dialysis were 93.3% and 65.1%, respectively, in this study, and these were similar to recent findings in Korea (88.6% and 66.3%) [9]. Several factors are thought to be involved in the favorable prognosis of patients with IgAN after starting dialysis.…”

“…Several reports indicate that the onset and continuance of IgAN increases the risk of CCVD events and mortality compared with the general population [7,8,9]. However, information about the incidence and risk factors for patients with IgAN undergoing renal replacement therapy (RRT) remains obscure.…”

Patient Characteristics and Outcomes by GN Subtype in ESRD

“…Mortality comparisons accounting for case-mix differences were, again, not performed. With the exception of this subgroup analysis, most other studies examining mortality outcomes after ERSD development in GN were restricted to single GN subtypes (3,(15)(16)(17) or combined subtypes into a single GN category (18,19), precluding direct comparisons across GN subtypes.…”

“…Treatment of patients with ESRD caused by GN incurs an estimated annual cost to Medicare alone of almost $3 billion (1). Mortality in GN increases dramatically after the onset of ESRD (2)(3)(4)(5); however, the relative contributions from generic ESRD-related factors and from the underlying cause of GN to this finding have not formally been evaluated.…”

The genetics and immunobiology of IgA nephropathy

“…Moreover, careful dissection of ethnicity-specific effects will be important, because the disease appears to have different features in East Asians and Europeans. For example, apart from dramatic differences in prevalence, biopsy series as well as ESRD registries indicate that the disease is equally frequent in males and females in East Asia (69)(70)(71)(72). In contrast, IgAN is strikingly more common in European males, with a male-to-female ratio often exceeding 3:1 (73)(74)(75)(76)(77).…”