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.

Disseminated cutaneous acanthamebiasis: a case report and review of the literature.

The genus Acanthamoeba includes species of free-living soil and water ameba that have been implicated in a small number of human diseases. Acanthamoeba species have been identified as the etiologic agents in 2 well-defined clinical entities, amebic keratitis and granulomatous amebic encephalitis (GAE). Less commonly, Acanthamoeba species have been identified as the cause of disseminated disease in debilitated and immunocompromised patients. Cutaneous acanthamebiasis, often a reflection of disseminated disease, is an increasingly recognized infection since the emergence of acquired immunodeficiency syndrome (AIDS) and the use of immunosuppressive drugs. The disease portends a poor prognosis and is uniformly fatal if the infection involves the central nervous system (CNS). We describe a patient with advanced AIDS who presented with disseminated cutaneous lesions, headache, and photophobia, and in whom a diagnosis of cutaneous acanthamebiasis was made based on the results of a skin biopsy. A multidrug therapeutic regimen was begun that included sulfadiazine; the patient responded favorably to treatment. This paper also reviews 36 previously reported cases of cutaneous acanthamebiasis with delineation of clinical, diagnostic, histologic, and prognostic features, as well as discusses treatment options.

Immediate type I hypersensitivity response implicated in worsening injection site reactions to adalimumab.

BACKGROUND: Tumor necrosis factor (TNF) inhibitors such as adalimumab, etanercept, and infliximab play an increasingly important role in the management of a variety of chronic inflammatory disorders. With their increasing use, a wide spectrum of dermatological adverse effects, including injection site reactions and the development of dermatitis, have been recognized. Previous studies have implicated the role of the delayed-type hypersensitivity reaction in mediation of injection site reactions to etanercept. To our knowledge, there have been no published studies on immunologic mechanism of injection site reactions to adalimumab to date. OBSERVATIONS: We describe 2 patients with a history of worsening injection site reactions to adalimumab. Findings from skin testing in both patients were suggestive of an immediate type I hypersensitivity reaction to adalimumab. A histamine release assay performed on peripheral blood leukocytes from both patients demonstrated significant histamine release on exposure to adalimumab. Furthermore, passive transfer of serum from one of the allergic patients to basophils from a nonatopic, healthy donor sensitized those cells to release significant amounts of histamine with exposure to adalimumab. Conclusion This study demonstrates that an IgE-mediated immediate type I hypersensitivity reaction plays a role in the mediation of worsening injection site reactions in some patients receiving adalimumab.