Ricardo Spina Nunes

Dermatophyte agents in the city of São Paulo, from 1992 to 2002

Dermatophytosis are superficial mycoses caused by fungi that can invade stratum corneum and keratinized tissues. In order to study the frequency of dermatophytes species and the clinical manifestations caused by these fungi, in São Paulo, SP, Brazil, the authors analyzed cultures isolated at the Mycology Laboratory from a selected population (15,300 out-patients of the Hospital das Clínicas, Department of Dermatology, Faculty of Medicine of University of São Paulo) from January 1992 to June 2002. The most prevalent dermatophyte was Trichophyton rubrum (48.7%), followed by Microsporum canis (20.9%), Trichophyton tonsurans (13.8%), Trichophyton mentagrophytes (9.7%), Epidermophyton floccosum (4.1%), and Microsporum gypseum (2.5%). These agents determined more than one clinical manifestation, i.e., tinea corporis (31.5%), tinea capitis (27.5%), tinea unguium (14.8%), tinea cruris (13.9%), tinea pedis (9.9%), and tinea manuum (1.9%). Clinical variants of dermatophytosis and their relationship to the etiologic agents were studied and the results were compared to those obtained in previous studies in other regions of Brazil and in other countries.

Susceptibility of sequential Fonsecaea pedrosoi isolates from chromoblastomycosis patients to antifungal agents

Fourteen Fonsecaea pedrosoi isolates from six chromoblastomycosis patients were submitted to susceptibility testing. Some patients were undergoing treatment with itraconazole (ITZ) and/or cryosurgery with liquid nitrogen. The antifungal agents amphotericin B (AMB), ITZ, fluconazole (FCZ), ketoconazole (KCZ), 5‐fluorocytosine (5‐FC), and terbinafine (TBF) were tested. AMB and FCZ showed less activity for all isolates. The most active agents were KCZ and TBF. Sequentially isolates from four patients presented ITZ minimal inhibitory concentration (MIC) higher than the previous ones; for two of these patients, response to therapy with this agent was not observed. These results suggest development of microbiologic resistance to ITZ in four instances, two of them coinciding with lack of clinical response to this drug.

Phaeohyphomycotic Cyst Caused by Colletotrichum crassipes

ABSTRACT A case of phaeohyphomycosis is reported in a male renal transplant recipient with a nodular lesion in the right leg who was treated with immunosuppressing drugs. The lesion consisted of a purulent cyst with thick walls. The cyst was excised surgically, and the patient did not receive any antifungal therapy. One year later he remains well. Histological study of the lesion showed a granulomatous reaction of epithelioid and multinucleate giant cells, with a central area of necrosis and pus. Fontana-Masson staining demonstrated the presence of pigmented hyphal elements. The fungus Colletotrichum crassipes was grown in different cultures from the cyst. The in vitro inhibitory activities of eight antifungal drugs against the isolate were tested. Clotrimazole and UR-9825 were the most active drugs. This case represents the first known reported infection caused by this rare species.

Estudo da proliferação linfocitária em pacientes sensibilizados ao níquel

FUNDAMENTO: O diagnostico da alergia ao niquel e estabelecido com a realizacao do teste de contato. OBJETIVO: Desenvolver um metodo diagnostico mais sensivel e especifico. CASUISTICAS E METODOS: Dezenove pacientes com teste de contato positivo para o niquel e 25 controles foram submetidos ao teste da proliferacao linfocitaria. As celulas mononucleadas foram isoladas do sangue venoso periferico e cultivadas em triplicatas, em placas de cultura (2x105 celulas/orificio) com: meio de cultura apenas; sulfato de niquel (156,25; 78,13; 19,53; 9,77 e 2,44µM) e concentracoes ideais do antigeno Candida albicans e dos mitogenos pokeweed, fito-hemaglutinina A e anticorpo anti-CD3 (OKT3). Timidina tritiada foi adicionada as placas, a radioatividade incorporada pelas celulas medida e os resultados expressos pelo indice de estimulacao (IE). RESULTADOS: A resposta proliferativa dos linfocitos dos casos foi superior a dos controles em todas as concentracoes de niquel testadas. Considerando teste positivo para niquel quando IE > 3, nenhum dos controles e 16 (84,21%) dos casos apresentaram teste positivo em pelo menos uma das cinco concentracoes usadas. As respostas a Candida albicans e aos mitogenos foram semelhantes nos casos e controles, demonstrando a integridade da imunidade celular em ambos os grupos. CONCLUSAO: O teste da proliferacao linfocitaria mostra-se util no diagnostico da alergia ao niquel.

In Situ Immune Response in Human Chromoblastomycosis – A Possible Role for Regulatory and Th17 T Cells

Background Chromoblastomycosis is a chronic fungal infection that affects skin and subcutaneous tissue. Lesions can be classified in tumorous, verrucous, cicatricial and plaque type. The cellular immune response in the severe form of the disease seems to correlate with a Th2 pattern of cytokines. The humoral immune response also seems to play a role. We intended to explore the populations of regulatory T cells and the Th17 pattern. Methodology Twenty-three biopsies of verrucous form were obtained from patients with clinical, culture and histopathological diagnostic of chromoblastomycosis, without treatment. It was performed an immunohistochemistry method to detect Foxp3, CD25, TGF-β, IL-6, IL-17 and IL-23. Principal findings IL-17 was the only cytokine with high expression in CBM when compared to normal skin. The expression of Treg cells, TGF- β, IL-6 and IL-23 were similar to normal skin. Conclusions/Significance The constitution of a local immune response with high expression of IL-17 and low expression of other cytokines could be at least in part, an attempt to help the immune system against fungal infection. On the other hand, high levels of local immune response mediated by Th17 profile could overcome the role of Treg cells. The inefficient immunomodulation as a consequence of the unbalance by Treg/Th17 cells seems to corroborate with the less effective immune response against fungi.

Phaeohyphomycosis in renal transplantation: report of two cases

Phaeohyphomycosis is an infection caused by a filamentous fungus that contains pigment melanin in its cell wall. We report two cases caused by Exophiala sp. emphasizing the clinical variability of the disease, as well as diagnostic and therapeutic difficulties of this opportunistic infection in immunosuppressed patients (kidney transplant).

Investigation of superficial mycosis in cutaneous allergy patients using topical or systemic corticosteroids

bilateral eyelid edema, associated with skin induration, which appeared 13 months before (Fig. 1a–b). The patient had induration of the skin with bright papules on the neck, shoulders, back, and arms. He reported a history of diabetes mellitus, dating from 10 years, under treatment with hypoglycemic drugs, and hypertriglyceridemia, treated with omega-3 fatty acids and statins. Routine laboratory investigations showed a high level of blood glucose (350 mg/dl), triglycerides (1333 mg/dl), cholesterol (231 mg/dl), glycosylated hemoglobin (HBGLI 10.1%), and C-reactive protein (35 mg/ml). Other routine laboratory investigations, including liver and renal tests, urinalysis, muscle function studies, serum and urinary protein electrophoresis, thyroid functions tests, and immunoserology were within normal limits or negative. Ophthalmologic, otolaryngologic, and neurologic exams were normal. An electrocardiogram, a whole-body computed tomography, and a magnetic resonance imaging examination of the head did not reveal any abnormality. Hematoxylin and eosin staining of the skin biopsy specimen from the periorbital area revealed fibrosis and edema in the dermis with a perivascular and periadnexal infiltrate of lymphocytes. In addition, basophils and histiocytes were observed in the dermis (Fig. 1c). Alcian blue staining showed sparse deposits of mucin between collagen bundles. Histology of the skin from the neck showed a marked thickening of the collagen bundles and scleredema in the dermis (Fig. 1d). Once the diagnosis of scleredema diabeticorum was confirmed, we prescribed treatment with oral corticosteroids (prednisone, 0.5 mg/kg daily) and insulin for 6 weeks with satisfactory improvement of the skin lesions. Surgical excision of the interested areas of the face will also be taken into consideration in case of relapse. The etiology of scleredema diabeticorum is unknown, but a role of advanced glycation end-products in the pathogenesis of this disorder has been suggested. These products and their receptors affect the balance of cellular proliferation and apoptosis, which may favor a fibrotic process that is common during the repair of the diabetic wounds. The presence of scleredema diabeticorum may be underrecognized in patients affected by diabetes, although it ranges from 2.5 to 14%. There is no geographic or gender predominance. Generally, these patients present with poorly-controlled diabetes, as was the case in our patient, which is frequently complicated by diabetic retinopathy and neuropathy. Treatment of hyperglycemia could contribute to reduce the clinical severity of this skin disorder. Corticosteroids, methotrexate, UV light therapy, photopheresis, and radiation therapy could be considered treatments with potential for clinical improvement.

Langerhans Cells Express IL-17A in the Epidermis of Chromoblastomycosis Lesions

Chromoblastomycosis (CBM) is a chronic fungal infection that affects skin and subcutaneous tissue, and little is known about the immunological aspects of such lesions. We have previously described the high expression of IL-17 in this group. Understanding the innate immune response of patients with CBM would improve the knowledge of its immunopathogenesis and contribute to the most appropriate therapies. Nineteen biopsies of verrucous form were obtained from patients with clinical and histopathological diagnosis of CBM, without treatment. This was done with a double immunostaining with conventional immunohistochemistry and immunofluorescence technique as well as confocal microscopy to detect Langerin and IL-17 expression. All of the specimens that were analyzed showed expression of Langerin in the epidermis - the same as the control group. However, only the CBM group presented cells expressing CD207 in the dermis. Interestingly, the coexpression of IL-17 and Langerin was visualized along the epidermis and dermis in 100% of the lesion group. We demonstrated for the first time in situ coexpression of IL-17 and Langerin (CD207) in epidermal cells of patients with CBM and speculated on their role as IL-17-producing cells or whether they could be a new subpopulation of dendritic cells distinct from Langerhans cells.