Livedoid vasculopathy associated with plasminogen activator inhibitor-1 promoter homozygosity (4G/4G) treated successfully with tissue plasminogen activator.

BACKGROUND

Livedoid vasculopathy (LV) is an occlusive thrombotic disease that affects primarily the small blood vessels of the lower extremities and often is associated with recurrent painful ulcerations. The pathogenesis of LV is unclear, but the disease is largely attributed to a hypercoagulable state. Factor V Leiden mutation, heterozygous protein C deficiency, homozygous hyperhomocysteinemia, and other inherited thrombophilias have been associated with LV. Plasminogen activator inhibitor-1 (PAI-1) is an important inhibitor of the fibrinolytic system. Elevated levels of PAI-1 are found in some patients with thrombotic diseases. Some of these patients are homozygous for an allele of PAI-1 containing a stretch of 4 guanines at base -675 in the promoter region. This variant is associated with elevated PAI-1 protein levels, impaired fibrinolysis, and increased risk of thrombosis.

OBSERVATIONS

A 33-year-old white woman had a 3-month history of painful enlarging ulcers on both ankles. Various therapies, including administration of oral antibiotic agents and prednisone up to 100 mg/d, to treat presumed vasculitis, were unsuccessful. Skin biopsy specimens revealed numerous thick-walled small blood vessels, many of which were filled with fibrin thrombi, in association with minimal perivascular inflammatory infiltrate, extensive epidermal necrosis, and focal ulceration. A diagnosis of thrombotic vasculopathy was made. Clinical workup revealed an elevated plasma level of PAI-1 (31 microM/mL; reference range, <25 microM/mL) and PAI-1 promoter 4G/4G homozygosity detected at DNA sequencing. Treatment with heparin sodium and tissue plasminogen activator dramatically improved the lesions, resulting in complete healing of the ulcerations. Continuation of anticoagulant therapy with warfarin sodium and episodic administration of tissue plasminogen activator was required for symptomatic control.

CONCLUSIONS

Patients with LV may have elevated plasma PAI-1 levels. This may be associated with the PAI-1 promoter 4G/4G genotype, which has not previously been linked with LV. Further studies in patients with LV are warranted to determine how frequently this genotype is present because it may identify responsiveness to fibrinolytic therapy.