VTE risk varies according to glomerulonephritis histologic subtype
MedWire News: The risk for venous thromboembolism (VTE) in patients with idiopathic glomerulonephritis is closely associated with the underlying histologic diagnosis, study findings indicate.
The risk is highest in patients with a histologic diagnosis of membranous nephropathy (MN), lowest in those with immunoglobulin-A nephropathy (IgAN), and intermediate among patients with focal segmental glomerulosclerosis (FSGS), report the researchers in the journal Kidney International.
Heather Reich (University of Toronto, Ontario, Canada) and colleagues explain that VTE is a potentially life-threatening complication of idiopathic glomerulonephritis.
"The risk for VTE has traditionally been thought to be highest in patients with MN; however, it is not clear whether this disease-specific risk is independent of clinical variables such as patient age or degree of proteinuria," they write.
The researchers therefore examined whether the underlying histologic diagnosis is an independent risk factor for the development of clinically evident VTE in 1313 patients (63% men) with idiopathic glomerulonephritis.
Of these, 395 had MN, 370 had FSGS, and 548 had IgAN.
During a median follow-up period of 63 months, there were 53 image-confirmed VTE events in 44 patients.
A significantly greater proportion of patients with MN developed VTE, compared with FSGS or IgAN, at 7.85% versus 2.97% and 0.36%, respectively.
Reich and co-authors note that the higher frequency of VTE in patients with MN was not solely attributable to a higher rate of renal vein thromboses (RVTs) in these patients; when RVTs were excluded, the rates of VTE were 4.80%, 2.70%, and 0.36% in patients with MN, FSGS, and IgAN, respectively.
Univariate analyses showed that histologic diagnosis, male gender, proteinuria at presentation, time-averaged (TA) proteinuria, albumin at presentation, TA albumin, and cancer were all associated with VTE risk.
Multivariate analysis, which accounted for these important clinical variables, showed that histologic diagnosis was independently associated with VTE risk. More specifically, patients with MN and FSGS had respective 10.8- and 5.9-fold increased risks for VTE compared with patients with IgAN.
Reich and co-authors remark that the mechanisms responsible for the increased VTE risk among patients with MN require further study and elucidation.
They conclude that "the next stage in analysis is an evaluation of the risks and benefits of prophylactic anticoagulation in patients with glomerulonephritis."
By Laura Dean