Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 154-175).

Leischmaniasis ist ein ernstzunehmende bedrohliche Erkrankung in vielen Ländern. Epidemien sind nicht unter Kontrolle, Neusbrüche werden in endemischen Ländern registriert. Darüber hinaus gibt es eine zunehmende Anzahl von Krankheitsfällen bei Reiserückkehrern in nicht endemischen Ländern . Für den individuellen Patienten sowie auch allgemein für die epidemiologische Kontrolle ist eine frühe und angemessene Therapie sehr wichtig. Als Voraussetzung ist eine präzise Diagnostik unabdingbar. Die Polymerase Ketten Reaktion (PCR) besitzt das größte Potential für die sensitive und spezies-spezifische Diagnostik der Leischmaniasis. Diese Studie ist in Israel und in der West Bank durchgeführt worden mit dem Ziel, eine sensitive und spezies-spezifische Diagnostik für Leischmaniasis im Land zu etablieren. Drei Arten von Leischmanien sind endemisch, Leishmania major,L.tropica, L.d.infantum, mit neuausbrechenden endemischen Foci in einigen Gegenden des Landes. Israelische Reiserückkehrer aus Zentral- und Südamerika kehren gelegentlich mit Infektionen aus der Neuen Welt zurück (L.braziliensis, L.mexicana Komplex). In dieser Studie wurden vor allem Proben direkt von denHautläsionen entnommen und auf Filter Papiekonserviert. Verschiedene DNA Extraktions- und PCR-Methoden wurden getestet. PCR wurde eingeführt für die Diagnostik von Patienten und auch zur Untersuchung von Infektionsraten bei Reservoirtieren. Ein Hauptziel der Studie war, die Methoden nach Praktikabilität, Zeit- und Kosteneffizienz testen, im Hinblick auf die Einführung der Methoden in klinischen Labors. / Leishmaniasis is a serious health threat in many countries around the world.Epidemics are hardly controlled, new foci are emerging in endemic countries. In addition,through tourism increasing numbers of infections are seen in non endemic countries. Early and adequate treatment is essential for the individual as well as for the control of the disease in general. As a prerequisite precise diagnosis is necessary. Diagnosis by the polymerase chain reaction (PCR) has the greatest potential for sensitive and species-specific diagnosis of leishmaniasis. This study has been carried out in Israel and the West Bank with the purpose to establish sensitive and species-specific diagnosis of leishmaniasis in the country. Three species of Leishmania are endemic, Leishmania major, L.tropica and L.d.infantumwith emerging foci in many parts of the country. Other species of the New World are occasionally imported by Israeli travelers returning from Central or South America (L.braziliensis and L.mexicana complex). The study focused on dermal lesion scrapings collected from suspected lesions and preserved on filter paper. Different DNA extraction and PCR methods have been tested. PCR was introduced forthe diagnosis of individual patients as well as for epidemiological studies in reservoir animals. It has been a major goal to select time and cost saving methods with regard to the introduction of PCR diagnosis of leishmaniasis to clinical laboratories.

Made available in DSpace on 2014-07-29T15:30:34Z (GMT). No. of bitstreams: 1 CRISTINA RODRIGUES DE OLIVEIRA.pdf: 2212867 bytes, checksum: a424437b0d0a13929b5f608708fec44a (MD5) Previous issue date: 2007-02-13 / The FcγRIIA, receptor for the Fc portion of IgG, expressed by macrophages, neutrophils, platelets and dendritic cells, bind to the subclasses of IgG with variable affinity, that can be influenced by the polymorphism in the gene that encodes this receptor. The substitution of the amino acid arginine (R) for histidine (H), in the 131 position, defines three allelic patterns, the homozygote H/H, R/R and the heterozygote H/R, conferring to the FcγRIIA H/H131 a greater affinity to the IgG2 and IgG3 subclasses. This can result in different responses to diverse pathogens. Studies show the importance of Fcγ receptors on the macrophage infection by amastigote forms of Leishmania sp, in addition to those for the complement (CR3) and for mannose (MR). Besides that, genetic factors related to the hosts are involved in the immune response to the leishmaniasis, among them, the FcγRs. Until this time, we haven t found studies relating the receptor FcγRIIA to the leishmaniasis in humans. This way, this work consists in analyzing the allelic polymorphism in the gene that encodes the FcRIIA in individuals with American Tegumentary Leishmaniasis (ATL), evaluate if this polymorphism would be a genetic fact of susceptibility or resistance for this disease, if this would be influencing in the development of the different clinical forms of the ATL, as well in the healing process of the lesions. The FcγRIIA H/R131 polymorphism was analyzed in 88 blood samples of individuals with leishmaniasis and in 98 samples of healthy individuals (control group), using PCR, amplifying a segment of the gene that encodes the FcRIIA, followed by allele-specific enzymatic digestion and agarose gel eletrophoresis 3%. These results showed that the genotypic and allelic distribution of the FcγRIIA H/R131 were similar in the patients with leishmaniasis and in the control group, as well in patients with different clinical forms of the ATL. Concerning the resolution time of the disease, among the patients that had their lesions healed within one month of treatment or after this period, there was a predominance of the alleles R and H, respectively, however these differences were not significant. This way, our study suggests that the allelic polymorphism of the FcγRIIA H/R131 possibly is not a genetic factor of host that is associated to the protection or pathogenesis in the American Tegumentary Leishmaniasis. / O FcyRIIA, receptor para região Fc de IgG, expresso por macrófagos, neutrófilos, plaquetas e células dendríticas, liga-se às subclasses de anticorpos IgG com afinidade variável, que pode ser influenciada pelo polimorfismo alélico no gene que codifica este receptor. A troca do aminoácido arginina (R) para histidina (H) na posição 131 determina três padrões alélicos: os homozigotos H/H e R/R e o heterozigoto H/R, conferindo ao FcγRIIA H/H131 maior afinidade para as subclasses IgG2 e IgG3. Isto pode resultar em diferentes respostas frente a patógenos diversos. Alguns estudos demonstram a importância dos receptores Fcγ na infecção de macrófagos por formas amastigotas de Leishmania sp, em adição aos receptores para complemento (CR3) e para manose (MR). Além disso, vários fatores genéticos do indivíduo estão envolvidos na resposta imune à leishmaniose, dentre esses os FcyRs. Até o presente momento, não encontramos estudos relacionando o receptor FcγRIIA com a leishmaniose em humanos. Assim, o presente trabalho teve como objetivo analisar o polimorfismo alélico no gene que codifica o receptor FcyRIIA em indivíduos com Leishmaniose Tegumentar Americana (LTA), avaliar se este polimorfismo seria um fator genético de susceptibilidade ou resistência para esta doença, se estaria influenciando no desenvolvimento das diferentes formas clínicas da LTA, bem como no tempo de cura das lesões. O polimorfismo do FcγRIIA H/R131 foi analisado em 88 amostras sangüíneas de indivíduos com LTA e em 98 amostras de indivíduos saudáveis (grupo controle), através da PCR, amplificando um segmento do gene que codifica o FcγRIIA, seguida de digestão enzimática alelo-específica e eletroforese em gel de agarose 3%. Nossos resultados demonstraram que a distribuição genotípica e alélica do FcγRIIA - H/R131 foi similar nos pacientes com leishmaniose e no grupo controle, bem como nos pacientes com as diferentes formas clínicas da LTA. Em relação ao tempo de resolução da doença, nos pacientes que tiveram suas lesões curadas com até um mês de tratamento ou após esse período, houve um predomínio do alelo R e do H, respectivamente, entretanto essas diferenças não foram significativas. Assim, nosso estudo sugere que o polimorfismo alélico do FcγRIIA H/R131 possivelmente não é um fator genético do hospedeiro que esteja associado com proteção ou patogênese na Leishmaniose Tegumentar Americana.