Letter to the Editor

A renal HIT

To the Editor:A 40-year-old female with history of Crohn’s disease pre-sented with acute pancreatitis and acute kidney injurywith anuria. Contrast-enhanced computerized tomogram(CECT) depicted bilateral cortical necrosis (Figure 1).Hemodialysis was initiated and continued to remaindialysis dependent. Four weeks later, she developed flareof her colitis and underwent colectomy with ileostomy.She had a fatal postoperative course with sudden-onsetbilateral flank pain, and shock. Laboratory investigationsrevealed thrombocytopenia and a positive heparin-induced thrombocytopenia (HIT) assay (enzyme-linkedimmunosorbent assay-based). A repeat CECT revealedlarge bilateral subcapsular renal hematomas withmarkedly atrophic kidneys (Figure 2). She was startedon continuous renal replacement therapy with citrateanticoagulation.

Bilateral cortical necrosis is rare and often irreversible.It is ascribed to the release of vasospastic or cytotoxicsubstances during pancreatitis. There is disturbed bloodflow to interlobular and afferent arterioles, whereas thearcuate arteries are usually spared.

HIT was first described in 1958 by Weismann andTobin.1 Apart from thrombocytopenia, the other presen-tations of HIT include thrombosis, skin necrosis, venouslimb gangrene, and acute systemic reaction after heparinbolus. A heparin-platelet factor 4-antibody complex leadsto platelet activation. HIT antibodies in patients undergo-ing hemodialysis range from 0% to 17.4%. No definiteclinical sequelae have been reported in this subgroup ofpatients.2 However, our patient developed spontaneousbilateral renal subcapsular hematomas.

Chronic dialysis patients undergoing surgery are atincreased risk of HIT within 2 weeks after surgery.3 Thepatho-mechanisms for HIT in such a setting remains

Correspondence to: A. Gupta, Division of Nephrology(Adult), The Ottawa Hospital – Riverside Campus 1967Riverside Drive, Room 511, Ottawa, ON, K1H 7W9,Canada. E-mail: parthankur@yahoo.com

Figure 1 Contrast-enhanced computerized tomogramshows bilateral acute renal cortical necrosis as hypodenseareas (arrows). A simple renal cortical cyst is also noted onright side. Free fluid is seen in bilateral paracolic gutter.

Figure 2 A repeat contrast-enhanced computerized tomo-gram after 4 weeks, shows complete atrophy of bilateralkidneys (thick arrow). In addition, large heterogeneoushypodense subcapsular hematomas (thin arrow) are seen.Interval increase in free fluid is also noted.

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© 2011 The AuthorsHemodialysis International © 2011 International Society for HemodialysisDOI:10.1111/j.1542-4758.2011.00625.x 1

elusive. It seems that the immune systems of thesepatients are altered by surgical stress in a way that HITbecomes more likely. This case depicts bilateral renal sub-capsular hematomas as a rare manifestation of HIT in adialysis patient.

Ashish KHANDELWAL,1

Ankur GUPTA,2

Preeti GUPTA3

1Department of Radiology, University of Ottawa, Ottawa,Canada; 2Division of Nephrology, University of Ottawa,

Ottawa, Canada; 3CGHS, New Delhi, India

Manuscript received August 2011.

REFERENCES1 Weismann RE, Tobin RW. Arterial embolism occurring

during systemic heparin therapy. AMA Arch Surg. 1958;76:219–225.

2 Syed S, Reilly RF. Heparin-induced thrombocytopenia: Arenal perspective. Nat Rev Nephrol. 2009; 5:501–511.

3 Tholl U, Greinacher A, Overdick K, Anlauf M. Life-threatening anaphylactic reaction following parathyroidec-tomy in a dialysis patient with heparin-inducedthrombocytopenia. Nephrol Dial Transplant. 1997;12:2750–2755.

Letter to the Editor

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