An 18 year-old female with no significant medical history was admitted to the pediatric unit with a three-day history of lower abdominal pain and a one-day history of nausea and vomiting. She had no fevers or urinary symptoms and review of systems was otherwise non-contributory. She had started an oral contraceptive pill the evening prior to the onset of pain and smoked cigarettes occasionally, but denied any illicit drug use. Imaging was performed to rule out a surgical abdomen, with computed tomography of the abdomen only notable for bilateral wedge-shaped hypodensities of the kidneys, consistent with renal infracts. Pelvic ultrasound with Doppler ruled out ovarian torsion. Urinalysis was significant for microscopic hematuria and a urine culture was negative. Creatinine was elevated for age at 1.07 mg/dl and serum CRP also elevated just above the reference range at 0.70 mg/dL. The remainder of the CMP, CBC, ESR and LDH were all within normal limits. Further laboratory assessment for thrombophilia and vasculitis was notable for a positive lupus anticoagulant (DRVVT ratio >2), elevated D-Dimer (833; reference range 0-230 ng/mL), and factor VIII (133%). Anticardiolipin antibodies, b2 glycoprotein, ANA, dsDNA, anti-Smith Ab, SSA/B antibodies were all negative. Factor V Leiden and prothrombin gene analysis did not reveal any mutations, and the remainder of thrombophilia laboratory assessment was negative. Doppler of the renal vasculature showed no renal artery stenosis. Due to concern for antiphospholipid syndrome (APLS)-related infarction, the patient was started on rivaroxaban to minimize risk of further thrombosis. Upon re-evaluation, one week later, D-Dimer normalized, microscopic hematuria resolved, and pain had also subsided.
Most cases of renal infarction have occurred in the elderly in the setting of cardiovascular disease, vasculitides and endocarditis with septic emboli, with this finding in children only described in the context of lupus. In our patient, the initial work-up for lupus was negative; however, one pediatric case report has documented APLS as a precursor to lupus. This patient will be monitored closely over time for the emergence of lupus, while continually being treated for APLS.
We present an unusual case of a teenager with bilateral renal infarcts and positive lupus anticoagulant with elevated Factor VIII with no current evidence of lupus. Given the rarity of this finding and its serious ramifications regarding future kidney function and possible further thrombosis, both aggressive anticoagulation and vigilant monitoring for evolution into classic lupus is indicated. Thrombotic and rheumatologic etiologies of renal infarction in the pediatric population should be considered high on the differential for this rare entity.