Case Presentation: A 27-year-old woman with a remote diagnosis of essential hypertension treated with hydrochlorothiazide-triamterene presented with five days of bilateral flank pain and nausea. On admission she was found to have a creatinine of 4.6mg/dL, from her baseline of 1mg/dL. She denied preceding illness, ingestions other than moderate alcohol use, or other known nephrotoxic insults. Initial exam was notable for mild tenderness to palpation in the bilateral flanks without fever, edema, or rash. Labs were notable for minimal proteinuria, trace hematuria, and absent casts. The patient’s creatinine uptrended to 5.6mg/dL, and she was treated empirically with one dose of methylprednisolone, with subsequent levels fluctuating between 3-5mg/dL. A broad serologic workup for antibody and immune-complex-mediated glomerular injury remained unrevealing. Renal ultrasound with doppler demonstrated normal sized kidneys with patent vasculature. Renal biopsy revealed organizing venous microthrombi and glomerular congestion accompanied by non-specific tubular injury concerning for thromboembolic disease. The patient subsequently underwent an extensive thrombophilia workup however this was also unrevealing. She remained largely asymptomatic and her renal function gradually recovered without further intervention, with creatinine normalizing to 0.8mg/dL ten days post discharge.
Discussion: This case adds to a small body of literature recognizing venous microthrombi-associated acute kidney injury (AKI) in young adults. Recent reports describe self-limited AKI associated with arcuate vein microthrombi in young, healthy adults, with spontaneous recovery within roughly two weeks. Recent alcohol consumption was a unifying factor among these cases however it is unclear whether this represents causal association with kidney injury. It remains possible that use of a dual-agent diuretic combined with diuretic effects of alcohol use precipitated microthrombus formation in this case. Given the transient nature of AKI in this and prior cases, it remains unanswered whether affected patients are at risk for recurrence of AKI, may be predisposed to development of chronic kidney disease or to systemic venous thrombosis. Trials of empiric anticoagulation have not been pursued in this population and surveillance guidelines, either with routine chemistry panels or newer kidney injury biomarkers, have yet to be addressed.
Conclusions: This is a case of unprovoked renal venous microthrombi formation associated with self-limited acute kidney injury in an otherwise healthy young woman. Taken together with recent similar published reports, this case may represent an as-yet-undefined mechanism of AKI in young adults and illustrates the need for providers to recognize similar constellations of findings in unexplained presentations of AKI in order to better explore its pathophysiology, surveillance, and treatment.
To cite this abstract:Sartori DJ, Wu M, Weisstuch JM, Adler NM. Surreptitious Venous Microthrombi Associated with Transient Acute Kidney Injury. Abstract published at Hospital Medicine 2016, March 6-9, San Diego, Calif. Abstract 780. Journal of Hospital Medicine. 2016; 11 (suppl 1). https://www.shmabstracts.com/abstract/surreptitious-venous-microthrombi-associated-with-transient-acute-kidney-injury/. Accessed April 25, 2019.