Human brain microvascular endothelial cell traversal by Borrelia burgdorferi requires calcium signaling.

Neurological manifestations of Lyme disease (or neuroborreliosis) occur variably and while it is clear that Borrelia burgdorferi can invade the nervous system, how it does so is not well understood. Pathogen penetration through the blood brain barrier (BBB) is often influenced by calcium signaling in the endothelial cells triggered by extracellular host-pathogen interactions. We examined the traversal of B. burgdorferi across the human BBB using in vitro model systems constructed of human brain microvascular endothelial cells (HBMEC) grown on Costar Transwell inserts. Pretreatment of the cell monolayers with BAPTA-AM (an intracellular calcium chelator) or phospholipase C (PLC) inhibitor U73122 inhibited B. burgdorferi transmigration. By 5 h, BAPTA-AM significantly inhibited (82-99%; p <0.017) spirochete traversal of HBMEC compared to DMSO controls. Spirochete traversal was almost totally blocked (> or =99%; p <0.017) after pretreatment with the PLC-beta inhibitor U73122 as a result of barrier tightening based on electric cell-substrate impedance sensing (ECIS). The data suggest a role for calcium signaling in CNS spirochete invasion through endothelial cell barriers.

Paraneoplastic pemphigus in association with Castleman's disease.

BACKGROUND: Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous disease associated with lymphoproliferative neoplasms, and frequently with a very rare tumour, Castleman's disease. OBJECTIVES: To analyse the clinical history, immunopathological and histopathological findings in 28 patients with a confirmed diagnosis of PNP and Castleman's disease. METHODS: Sera from all patients were assayed by indirect immunofluorescence (IF) and immunoprecipitation (IP) for plakin autoantibodies, immunoblotting for detection of plectin autoantibodies, and enzyme-linked immunosorbent assay for detection of desmoglein (Dsg)1 and Dsg3 autoantibodies. RESULTS: Severe oral mucositis was observed in all patients, and lichenoid cutaneous lesions were seen in 19 of 28. Twenty cases of Castleman's disease were of the hyaline vascular type, four were of plasmacytoid type and four were of mixed type. Striking findings included pulmonary destruction leading to bronchiolitis obliterans in 26 patients and fatal outcome due to respiratory failure in 22 patients with pulmonary involvement. Histological findings included lichenoid and interface dermatitis with variable intraepithelial acantholysis. Direct IF showed deposition of IgG and C3 in the mouth and skin in 24 of 28 patients. However, indirect IF detected serum IgG autoantibodies in all patients. IP revealed IgG autoantibodies against desmoplakin I, envoplakin and periplakin in all cases, and against desmoplakin II and the 170-kDa antigen in 19 patients. Dsg3 and Dsg1 autoantibodies were present in 22 and 11 patients, respectively, and plectin autoantibodies in 23 patients. CONCLUSIONS: PNP in association with Castleman's disease presents with severe oral mucositis and cutaneous lichenoid lesions. Serum autoantibodies against plakin proteins are the most diagnostic markers. Pulmonary injury with respiratory failure is the cause of death in most cases.

Cutaneous polyarteritis nodosa in patients presenting with atrophie blanche.

BACKGROUND: The term 'atrophie blanche' is used both as a descriptive term denoting ivory-white stellate scars on the lower limbs as well as a diagnostic label synonymous with livedoid vasculitis, an ill-defined entity. Medium-sized vasculitides, such as polyarteritis nodosa (PAN), occasionally present with ulceration resulting in ivory-white stellate scarring on the lower limbs and may potentially be misdiagnosed as livedoid vasculitis. OBJECTIVES: To assess the occurrence, clinical and immunopathological features of medium-sized vasculitis in patients presenting with atrophie blanche without clinical and/or compression duplex ultrasonographic evidence of venous insufficiency. METHODS: We retrospectively evaluated patients presenting with atrophie blanche at the Department of Dermatology of Johns Hopkins Medical Institutions, from April 1996 until April 2002, following the diagnostic guidelines for leg ulcers of the Division of Immunodermatology. Deep and multiple skin biopsies were performed for histology. Investigations for underlying vasculitis, thrombophilia, nerve conduction studies and compression duplex ultrasonography of the lower extremities were performed in all patients. RESULTS: Of 29 consecutive patients presenting with atrophie blanche, six had underlying medium-sized vasculitis consistent with PAN, three of whom had previously been diagnosed to have segmental hyalinizing vasculitis/vasculopathy (livedoid vasculitis/vasculopathy) on superficial biopsies. All six patients with cutaneous PAN were women with a median age of 36.5 years (range 34-46) and with a median duration of the disease prior to diagnosis of 18 years (range 3-30). Of the six cutaneous PAN patients, four had neurological involvement evidenced by clinical symptoms and nerve conduction studies. No evidence of any other extracutaneous involvement was found. Erythrocyte sedimentation rate and tests for vasculitis and thrombophilic were normal in all six patients. None had evidence of venous insufficiency. Immunosuppressive therapy was effective in controlling PAN-associated cutaneous and neurological disease. Of the remaining 23 patients, two had antiphospholipid syndrome and one had homocystineaemia; all three also had evidence of venous insufficiency. One patient had multiple myeloma-associated type I cryoglobulinaemia and 19 patients had venous insufficiency alone. None of the non-PAN patients had abnormalities in the nerve conduction studies. CONCLUSIONS: In patients presenting with atrophie blanche without evidence of venous insufficiency and thrombophilia, PAN should be excluded, particularly in the presence of mononeuritis multiplex. Repeated and deep biopsies are often necessary to reveal the accurate underlying pathology of necrotizing medium-sized vasculitis in the reticular dermis and the subcutis, especially in the setting of atrophie blanche lesions. Immunosuppressive therapy was effective in controlling the PAN-associated clinical manifestations.