IgA Nephropathy in Elderly Patients
Authors: Sevillano Angel M. , Diaz Monserrat , Caravaca-Fontán Fernando , Barrios Clara , Bernis Carmen , Cabrera Jimena , Calviño Jesus , Castillo Lorena , Cobelo Carmen , Delgado-Mallén Patricia , Espinosa Mario , Fernandez-Juarez Gema , Fernandez-Reyes Maria Jose , Garcia-Osuna Rosa , Garcia Patricia , Goicoechea Marian , Gonzalez-Cabrera Fayna , Guzmán Diomaris A. , Heras Manuel , Martín-Reyes Guillermo , Martinez Alberto , Olea Teresa , Peña Jessy Korina , Quintana Luis F. , Rabasco Cristina , López Revuelta Katia , Rodas Lida , Rodriguez-Mendiola Nuria , Rodriguez Eva , San Miguel Luz , Sanchez de la Nieta Maria Dolores , Shabaka Amir , Sierra Milagros , Valera Alfonso , Velo Mercedes , Verde Eduardo , Ballarin Jose , Noboa Oscar , Moreno Juan Antonio , Gutiérrez Eduardo , Praga Manuel ,   on behalf of the Spanish Group for the Study of Glomerular Diseases (GLOSEN)
Published: July 2019

Background and objectives
Some studies suggest that the incidence of IgA nephropathy is increasing in older adults, but there is a lack of information about the epidemiology and behavior of the disease in that age group.

Design, setting, participants, & measurements
In this retrospective multicentric study, we analyzed the incidence, forms of presentation, clinical and histologic characteristics, treatments received, and outcomes in a cohort of 151 patients ≥65 years old with biopsy-proven IgA nephropathy diagnosed between 1990 and 2015. The main outcome was a composite end point of kidney replacement therapy or death before kidney replacement therapy.

Results
We found a significant increase in the diagnosis of IgA nephropathy over time from six patients in 1990–1995 to 62 in 2011–2015 (P value for trend =0.03). After asymptomatic urinary abnormalities (84 patients; 55%), AKI was the most common form of presentation (61 patients; 40%). Within the latter, 53 (86%) patients presented with hematuria-related AKI (gross hematuria and tubular necrosis associated with erythrocyte casts as the most important lesions in kidney biopsy), and eight patients presented with crescentic IgA nephropathy. Six (4%) patients presented with nephrotic syndrome. Among hematuria-related AKI, 18 (34%) patients were receiving oral anticoagulants, and this proportion rose to 42% among the 34 patients older than 72 years old who presented with hematuria-related AKI. For the whole cohort, survival rates without the composite end point were 74%, 48%, and 26% at 1, 2, and 5 years, respectively. Age, serum creatinine at presentation, and the degree of interstitial fibrosis in kidney biopsy were risk factors significantly associated with the outcome, whereas treatment with renin-angiotensin-aldosterone blockers was associated with a lower risk. Immunosuppressive treatments were not significantly associated with the outcome.

Conclusions
The diagnosis of IgA nephropathy among older adults in Spain has progressively increased in recent years, and anticoagulant therapy may be partially responsible for this trend. Prognosis was poor.

Podcast
This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_07_16_CJASNPodcast_19_08_.mp3