A 60 year old male presented with acute dyspnea and pleuritic retrosternal chest pain. His past medical history was significant for Wegener’s granulomatosis (WG) in remission for four years. His history was negative for venous thromboembolism (VTE) risk factors or prior VTE. He was up to date on age appropriate malignancy screening. His medications included prednisone, azathioprine, and trimethoprim/sulfamethoxazole. On exam, vital signs showed his blood pressure at 143/89, heart rate 105 beats / minute, respirations 24 breaths / minute and oxygen saturation below 80% with minimal activity requiring 2 liters of supplemental oxygen. He had reproducible chest pain with sternal palpation and right calf tenderness. The remainder of his exam was unremarkable. An electrocardiogram showed a S1Q3T3 pattern. Chest CT angiography demonstrated a saddle pulmonary embolism with large bilateral extension to the right and left pulmonary arteries. A lower extremity ultrasound showed a large right occlusive thrombus extending distally from the femoral vein. Laboratory analysis demonstrated mild acute renal injury with creatinine elevated from 1.3 mg/dL (baseline 0.8 mg/dL) and microscopic hematuria. Additional workup showed elevated erythrocyte sedimentation rate at 40 mm/1 hr, C reactive protein at 35.7 mg/L and cytoplasmic antineutrophil cytoplasmic antibodies (c–ANCA) at 1:512 dilution. Proteinase–3 was elevated at 4.5 units. Antiphospholipid antibody testing was unremarkable. These findings were consistent with occult WG relapse. High dose prednisone and rituximab were started in addition to unfractionated heparin. The patient’s renal function improved to baseline and his symptoms resolved. Warfarin was started and compression wraps were applied to the right lower extremity. At discharge, the patient was ambulating without need for supplemental oxygen. He was scheduled with close followup in Rheumatology, Pulmonology and weekly rituximab therapy.
Emerging evidence has shown an association between active WG and VTEs. The WeCLOT study demonstrated the incidence of VTE may be as high as 7.0 per 100 person–years in active WG patients compared to the incidence of 0.3 per 100 person–years in the normal population. Active vasculitis is believed to predispose to VTE formation by ANCA associated endothelial damage and circulation of proinflammatory cytokines leading to increased tissue factor expression and hypercoagulability. VTE prophylaxis is not routinely administered in this patient population due to the potential risk of alveolar hemorrhage or renal damage during active disease. In our patient, an otherwise “unprovoked” VTE served as a marker of insidious WG relapse.
Patients with active WG are at increased VTE risk. Recognition of this association may lead to prompt diagnosis, early modification of immunotherapy and timely anticoagulation.