A potassium-titanyl-phosphate laser is an efficacious tool in the treatment of pyogenic granulomas. A retrospective study in 28 patients.

BACKGROUND AND OBJECTIVE: Pyogenic granuloma is a common benign vascular lesion of the skin and mucosa prone to ulceration and bleeding. Current therapeutic approaches include surgical excision, removal by means of electro caustic therapy, cryotherapy, and ablation with CO2 or vascular lasers. The purpose of this study was to investigate the efficacy of a 532 nm potassium-titanyl-phosphate laser (KTP-laser) for the treatment of pyogenic granulomas in terms of efficacy, advantages in clinical outcome, technique and associated side effects. METHODS: In this retrospective study we report on the response of 28 consecutive patients with pyogenic granulomas at multiple locations on the skin after having been treated with a 532 nm KTP laser (532 nm AuraTM Star Pulse laser, Laserscope, CA, USA). Treatment was performed with a 2 mm handpiece and energy fluences of 35-60 J cm-2 and a laser pulse width of 50 ms or with a 1 mm handpiece and energy fluences of 200-240 J cm-2 and a laser pulse width of 50 ms. All patients were treated on an outpatient basis at the department of dermatology, Medical University of Vienna, Austria. RESULTS: In all of the 28 patients treated, we were able to demonstrate both symptomatic and clinical clearing of the lesions with excellent cosmetic results after the treatment. In 25 of the 28 patients a single treatment was sufficient to obtain optimal results. In three patients a second treatment session was required due to the recurrence of the lesion. The procedure required only local anesthesia, and postoperative care was limited to the application of a topical antibiotic ointment. No postoperative complications such as increased pain or wound infection and only minimal scarring were observed. CONCLUSIONS: This experience with excellent patient satisfaction suggests that treatment of pyogenic granulomas with the KTP laser is a safe, effective, and reasonable alternative to conventional therapy. As with many other limited interventions with this laser technology, the advantages include minimal postoperative pain, conservative site-specific minimally invasive surgeries and a very satisfactory cosmetic result with a high acceptance rate on the side of the patients.

Extended monitoring of hemostatic activation after varicose vein surgery under general anesthesia.

BACKGROUND: Postoperative heparin prophylaxis after stripping of the long saphenous vein is a matter of controversial discussion, and practices vary by surgeon and country. OBJECTIVE: The aim of this study was to assess the extent of hypercoagulability by continued monitoring of activation markers of coagulation and fibrinolysis for a period of 3 weeks after stripping of the long saphenous vein and concomitant phlebectomy. METHODS: Including 21 patients, the following markers were measured preoperatively and on postoperative day 1, 2, 3, 7, 14, and 21: Activation products of coagulation: thrombin-antithrombin complex (TAT), thrombus precursor protein (TPP), and prothrombin-fragment F1+2 (F1+2), and markers of fibrinolysis: plasmin-alpha(2)-antiplasmin complexes (PAP), D-Dimer, tissue plasminogen activator (t-PA) antigen, and plasminogen activator inhibitor 1 (PAI-1) antigen. RESULTS: TAT levels increased significantly until day 3 (p=.008) and normalized within 14 days. TPP levels increased significantly until day 7 (p=.02), decreasing to initial values within 21 days. PAP complexes increased significantly until day 2 (p=.02) reducing to baseline within the observation period. D-Dimer levels increased immediately after surgery (p<.001) until day 14 (p<.001) and returned to baseline until day 21. CONCLUSIONS: Significant hemostatic activation after varicose vein surgery was observed and persisted until 3 weeks postoperatively, indicating that heparin prophylaxis for 2 to 3 weeks is advisable for at-risk patients.

Expression of FcRn, the MHC class I-related receptor for IgG, in human keratinocytes.

The neonatal Fc receptor (FcRn) for IgG has been shown to be responsible for IgG transport and to be involved in IgG catabolism. In this study, we show expression of FcRn in normal human epidermal keratinocytes. By RT-PCR, we demonstrate the FcRn alpha-chain mRNA obtained from cultured keratinocytes creating a 457 bp product as confirmed by sequence analysis. Northern blot analysis shows a 1.5 kb transcript. Real-time PCR reveals consistent expression of FcRn alpha-chain mRNA in human keratinocytes from different donors. Anti-FcRn alpha2-extracellular domain and anti-FcRn cytoplasmic tail antibody (Ab) directed against defined antigenic targets were generated and used for immunoblotting and immunoprecipitation revealing protein expression of the 46 kDa FcRn alpha-chain. By immunofluorescence microscopy, we find granular-vesicular staining for FcRn alpha-chain in keratinocytes. Fluorescence-activated cell sorting analysis gives predominantly an intracellular distribution of FcRn in keratinocytes. Biochemically, we demonstrate Fc-dependent binding of human IgG at acidic pH. In normal human epidermis, we find a cytoplasmic vesicular staining of predominantly basal and suprabasal keratinocytes. In summary, we demonstrate expression of a functional FcRn in normal human epidermal keratinocytes. These findings further emphasize the role of keratinocytes as immunomodulating cells in inflammatory and immunologic processes of the skin.

Unusual clinical manifestation of linear IgA dermatosis: a report of two cases.

Linear IgA dermatosis is a rare autoimmune bullous skin disease with subepidermal blister formation and linear IgA deposits along the basement membrane zone. We describe two female patients showing erythematous annular plaques with scaling at the margin, strictly localized to the palms in one patient, and also found on the soles and buttocks in the second patient. Histology showed numerous neutrophils in the dermis with an admixture of eosinophils, some subepidermal clefting, and occasional papillary microabscesses. Direct immunofluorescence and immunoelectron microscopy revealed in vivo IgA deposition along the basement membrane zone. One patient cleared after treatment with dapsone. The second patient did not respond to dapsone alone and various immunosuppressive treatment regimens. Considerable improvement was achieved with intravenous immunoglobulin therapy combined with corticosteroid and dapsone.

RPE65 of retinal pigment epithelium, a putative receptor molecule for plasma retinol-binding protein, is expressed in human keratinocytes.

Retinoids are important modulators for cell growth and differentiation of normal skin. In plasma, retinol is transported coupled to plasma retinol-binding protein. In this study, we investigated gene and protein expression of RPE65, a putative receptor for plasma retinol-binding protein in human epidermal keratinocytes. We performed real-time PCR analysis to evaluate expression of RPE65 mRNA in proliferating and differentiating keratinocytes. Immunoblotting with anti-RPE65 antibody shows distinct reactivity to a 61-kDa protein. Indirect immunofluorescence on normal human epidermis reveals cell surface labeling of keratinocytes. Laser scan microscopy exhibits colocalization of plasma retinol-binding protein and RPE65 on cultured keratinocytes. Internalization experiments with [3H]retinoic acid-retinol-binding protein complex in the presence and absence of excess of retinol-binding protein indicates receptor-dependent uptake of retinoids. We further show isolation of RPE65 protein by affinity chromatography from lysates of keratinocytes using a retinol-binding protein-matrix gel column. In summary, we demonstrate mRNA and protein expression of RPE65 in epidermal keratinocytes. Colocalization of plasma retinol-binding protein with RPE65 and affinity binding suggest a direct interaction of RPE65 with plasma retinol-binding protein in cultured human keratinocytes that might be involved in retinoid uptake of keratinocytes.

Paraneoplastic pemphigus in association with hepatocellular carcinoma.

Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous blistering disease associated with neoplasms, most frequently of the lymphoproliferative type. Rare PNP cases related to nonhematological solid tumors have been reported. The patient in this report presented with severe mucocutaneous involvement of PNP associated with hepatocellular carcinoma. Histopathology showed vacuolar interface dermatitis with keratinocyte necrosis and intraepidermal acantholysis. Direct immunofluorescence exhibited deposition of intercellular IgG and complement and granular complement at the dermoepidermal junction. Indirect immunofluorescence testing showed a typical intercellular staining on monkey esophagus and rat bladder epithelium. Immunoprecipitation showed characteristic target antigens of 250, 210, and 190 kDa molecular weights. This patient met all diagnostic criteria for paraneoplastic pemphigus and is, to our knowledge, the first report of a case associated with hepatocellular carcinoma.

RasGAP-like protein IQGAP1 is expressed by human keratinocytes and recognized by autoantibodies in association with bullous skin disease.

Autoantibodies in patients with autoimmune bullous skin diseases, such as pemphigus or bullous pemphigoid are of diagnostic value and might play a part in the pathogenic scenario. In this study we present five patients with erythematous plaques, subepidermal blister formation of the skin, and the presence of circulating autoantibodies directed against a so far unrecognized 190 kDa antigen in human keratinocytes. Amino acid sequence analysis identified the protein as IQGAP1, a recently described human Ras GTPase-activating-like protein suspected to act as an effector molecule for Cdc42 and Rac1, members of the Rho small GTPase family and to play a key part in regulating E-cadherin-mediated cell adhesion. The protein is selectively recognized by a monoclonal anti-IQGAP1 antibody on western blots and immunoprecipitates from keratinocyte extracts. Indirect immunofluorescence locates IQGAP1 within individual keratinocytes in a cytoplasmic pattern and along the cell periphery at adhesive sites. Our results demonstrate IQGAP1, a newly described multifunctional protein, to be constitutively expressed in human keratinocytes where it may contribute to the integrity of the epidermal layer. Furthermore, we found autoantibodies reacting with IQGAP1 in patients with bullous skin eruptions most apparently belonging to the spectrum of bullous pemphigoid.

Internalization via plasmalemmal vesicles: a route for antidesmoplakin autoantibodies into cultured human keratinocytes.

Recently, autoantibodies to desmoplakin I and II have been identified in a subset of patients with a severe form of erythema multiforme. These autoantibodies recognize a specific peptide sequence at the carboxy terminal domain of desmoplakin I and II responsible for interaction with keratin filaments. Desmoplakins are major constitutive proteins of the inner dense desmosomal plaque of keratinocytes and are entirely localized within the cells. With the assumption of pathogenecity for circulating autoantibodies, the question arose how antidesmoplakin autoantibodies enter keratinocytes. Utilizing immunhistochemical procedures for cell motility and time kinetic studies at the light- and electron-microscopic level, we found that autoantibodies are bound at the cell surface of cultured human keratinocytes, internalized via plasmalemmal vesicles, and are found consecutively within tubulovesicular structures inside the cells. At the same time, a fraction of antibodies can be detected at the inner dense desmosomal plaques. Immunogold labeling reveals internalization of autoantibodies in small non-coated plasmalemmal vesicles positive for caveolin. These observations indicate that vesicular transport may represent a relevant biological mechanism for antidesmoplakin autoantibodies to enter keratinocytes and allow access to their corresponding antigenic target in vivo.

FcgammaRIII expression on cultured human keratinocytes and upregulation by interferon-gamma.

Keratinocytes of human epidermis are actively involved in inflammatory and autoimmune reactions of the skin and interact with resident or infiltrating immunocompetent cells via cytokines, chemokines, and intercellular adhesion mechanisms. Most immunocompetent cells have been reported to express Fcgamma receptors (FcgammaR), which are important for immunoregulatory functions. In this study we investigate FcgammaRIII expression on cultured human keratinocytes and upregulation by interferon-gamma. By real-time polymerase chain reaction, we show basal mRNA expression of both subclasses FcgammaRIIIA and FcgammaRIIIB, but after interferon-gamma treatment mRNA of FcgammaRIIIA and FcgammaRIIIB is increased 4.4 and 6.5 times, respectively. FcgammaRIII protein expression and its increase after interferon-gamma treatment were shown on cultured human keratinocytes by indirect immunofluorescence. In immunoblotting experiments, a bonified anti-CD16 antibody revealed reactivity to a polypeptide of 50-65 kDa on lysates of treated and untreated keratinocytes. In summary, we demonstrate expression of mRNA specific for the FcgammaRIIIA and FcgammaRIIIB subclasses and their upregulation by interferon-gamma on human keratinocytes in vitro, and confirm FcgammaRIII protein expression by indirect immunofluorescence and by immunoblotting experiments.

Organotypic keratinocyte coculture using normal human serum: an immunomorphological study at light and electron microscopic levels.

Organotypic human skin equivalents of keratinocytes and fibroblasts embedded in collagen matrix have been the subject of studies dealing with various culture conditions. Development of standardized living skin equivalents using defined culture media containing respective supplements can provide important instruments of investigation in skin biology. In addition, tissue engineering has created human skin substitutes for treatment of acute and chronic wounds. In our study, we generate a modified organotypic human skin equivalent using normal human serum instead of fetal calf serum (FCS). This living skin equivalent shows regular stratification of the epidermis and the dermal-epidermal junction zone at the light and electron microscopic level after 1 and 3 weeks of coculture. Indirect immunofluorescence reveals regular expression of differentiation antigens and the major structural proteins collagen IV, laminin 5 and the integrin chains alpha 6 and beta 4 at the dermo-epidermal junction zone. Immunoelectron microscopy demonstrates expression of collagen IV, alpha 6 and beta 4 integrin after 1 and 3 weeks of coculture. This organotypic skin model could be the basis for autologous skin grafting for acute or chronic wounds using autologous serum as well as patients' keratinocytes and fibroblasts, thus minimizing the risk of transmitting infectious agents.