PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Leishmaniasis, Diffuse Cutaneous”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

Genetic polymorphism of Leishmania species using kinetoplast DNA restriction fragment length polymorphism and cDNA probe of Leishmania donovani.

Leishmaniasis represents a group of diseases that range from simple cutaneous lesions through metastasizing diffused cutaneous to severe systemic infection depending upon the taxon to which the causative parasite belongs. Therefore, it is important to identify the infecting Leishmania. Methods presently being used, including immunology, biochemistry and molecular biology have one or the other limitations, leaving scope for the search for newer probes. This study reports the characterization of leishmania isolates both by restriction fragment length polymorphism of kinetoplast DNA (kDNA) and genomic DNA. The genomic DNA was probed with a cDNA probe B2a1. Using a kDNA restriction pattern technique, different isolates of Leishmania donovani could be differentiated from the UR6 strain of L. tropica, but it was not possible to differentiate between newer local isolates of L. donovani with most of the restriction enzymes except AluI. However, the B2a1 cDNA probe was able to differentiate these isolates effectively. Both of these techniques could differentiate newer local isolates of L. donovani from the older isolates of L. donovani from India, i.e., DD8, RMRI and SS. The Indian isolates of L. donovani could also be differentiated from isolates of L. donovani from Jeddah and Germany using both techniques. The present study indicates that the cDNA probe B2a1 can be used as an important adjunct to kDNA restriction analysis for the characterization of Leishmania species.

Animals↗

[Histopathology of the localized form of cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis].

The microscopic changes found in the localized form of the human cutaneous leishmaniasis due to Leishmania (Leishmania) amazonensis are reported. In this form, less known than the diffuse one caused by the same species, the clinical manifestations are identical to those produced by other Leishmania species of the subgenus Viannia. There is, however, in the localized infection by L. (L.) amazonensis, a peculiar feature, only recently discovered: about 50% of the affected individuals are Montenegro-negatives. The main histologic change observed in the skin sections was the presence of groups of macrophages with a large vacuole in the cytoplasm, containing many amastigotes. The microscopic picture is similar to that found in the diffuse form of the disease, the difference being only quantitative. When in large numbers, the macrophages suffers necrosis, which generally starts at the center of the groups. First, in this process, the membrane of the parasitized cells ruptures, and the amastigotes become free; later, both cells and parasites are destroyed. The picture can be seen either in Montenegro-negative or in Montenegro-positive patients. The macrophages with amastigotes may persist in tissues for as long as 6-7 months, while in the infections due to L. (V.) braziliensis the parasites usually disappear in a few weeks.

Adolescent↗

[Comparative histopathologic study of the skin test in dogs from an endemic area of tegumentary leishmaniasis, using 2 antigens: Leishvacin and P10.000G].

The Montenegro skin test is widely used as a diagnostic method for American cutaneous leishmaniasis (ACL). However, there is little information about the histological changes that occur after administration of the antigen, especially in dogs. Two intradermal reactions were used in mongrel dogs during a clinical and epidemiological study as a diagnostic method for canine cutaneous leishmaniasis at Virginópolis, Minas Gerais, Brazil. Leishvacin and P10,000G were used as antigens. The inflammatory reaction was more intense and diffuse in dogs tested with P10,000G than Leishvacin.

Animals↗

Serodiagnosis of leishmaniasis.

Leishmaniasis is a spectrum of diseases ranging in severity from cutaneous (CL), post-kala-azar dermal (PKDL), and diffuse cutaneous (DCL) to mucocutaneous (MCL) and visceral (VL) infections that are endemic in 86 tropical and subtropical countries around the world, accounting for 75,000 deaths per year. Different forms of leishmaniases are generally caused by different distinct species of Leishmania having a digenetic life cycle alternating between an aflagellated amastigote form replicative within the macrophages of the host and a flagellated promastigote form that multiplies within the gut of the sandfly. VL, MCL, PKDL, DCL, and CL forms of the disease can be arranged on a priority basis in accordance with the humoral immune responses of host. Generally, the cell-mediated immunity, particularly the delayed-type hypersensitivity to leishmanial antigens, is associated with CL, MCL, PKDL, and cured VL cases. The serodiagnosis of leishmaniasis appears to be an alternative to parasite detection in biopsy samples either by the staining of amastigotes or by culturing the amastigotes, which transform to a promastigote form and replicate. A battery of immunological procedures have been developed or adapted to demonstrate either humoral or cell-mediated immune responses against Leishmania for diagnosis and epidemiological survey. The sensitivity and specificity of such diagnostic methods depend on the type, source, and purity of antigen employed, as some of the leishmanial antigens have common cross-reactive epitopes shared with other microorganisms, particularly Trypanosoma, Mycobacteria, Plasmodia, and Schistosoma. Serodiagnostic techniques for the detection of antileishmanial antibodies have been employed with about 72 to 100, 23 to 90, 83, and 33 to 100% success in VL, CL, MCL, and PKDL patients, respectively. The Leishmanin skin test (LST) is useful to detect MCL and CL, with about 100 and 84% success, respectively. In PKDL, the gradual fall of antileishmanial antibody titer to some extent and the rise of delayed hypersensitivity to the parasite antigen are the characteristic features associated with the chronicity of the disease. The use of whole promastigote as the source of antigens in the direct agglutination test (DAT) and immunofluorescent test (IFAT) gave cross-reactions with the sera of leprosy, tuberculosis, and African trypanosomiasis patients. Again, the use of cell-free extracts of promastigotes generally gave false positive results with the sera of normal human and Chagas' disease, leprosy, tuberculosis, and malaria patients in enzyme-linked immunosorbent assay (ELISA), dot ELISA, immunodiffusion, immunoelectrophoresis, and counter-current immunoelectrophoresis tests.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

[Canine leishmaniasis in Italy from 1910 to 1993].

Canine leishmaniasis has first been recorded in Italy by Basile (1910). Since then, many cases have been reported. In order to have a general picture of canine leishmaniasis distribution in Italy, from 1910 up to present times, we have collected all records of leishmaniotic dogs which have appeared in the literature, integrated by personal data. A map has been drawn, according to the origin of cases, showing: the present distribution of canine leishmaniasis in central and southern Italy and its islands; the persistence of canine leishmaniasis in some foci for the last 70 years or more; the increasing trend of new foci reports from the pre-war to present times. As opposed to the high diffusion of canine leishmaniasis there has been, in Italy, a marked reduction of human cases of visceral and cutaneous leishmaniasis, a phenomenon which has been observed in other Mediterranean countries as well. Recent data on the epizoology of canine leishmaniasis are discussed.

Animals↗

Histological spectrum of cutaneous leishmaniasis due to Leishmania tropica.

Skin biopsies from 117 cases of acute and 23 cases of lupoid leishmaniasis were studied. Of the 117 acute cases, anergic macrophage response were seen in 44, diffuse necrosis in 9 and focalized necrosis in 11 biopsies; the remaining 53 biopsies showed scanty or no parasites with a few to abundant epithelioid cells probably representing post necrotic changes before complete healing of the lesions. The 23 biopsies of lupoid leishmaniasis showed rather well organized epithelioid granulomata surrounded by lymphocytes, inconspicuous plasma cells, no amastigotes and no necrosis. Lupoid cases showed strong delayed hypersensitivity with leishmanin and low serum antibody titres. It appears that the lesions of urban cutaneous leishmaniasis spend a long time in the anergic phase. Partial destruction of parasites by activated macrophages together with gradual elevation of antibody levels prepares the appropriate antigen-antibody ratio for optimum development of necrosis at PI3 leading to effective elimination of parasites. Plasma cells appear to be important in the induction of necrosis and inhibition of epithelioid granulomata. A significant inverse relationship has been found between plasma cells and epitheloid cells. The delayed hypersensitivity observed in lupoid leishmaniasis is probably the result of a poor humoral response evidenced by inconspicuous plasma cells and low serum antibody titres.

Adolescent↗

Leishmaniasis in the Caribbean Islands. A review.

A review is presented of the current knowledge relating to leishmaniasis in the West Indies. The only country where an autochthonous focus of cutaneous leishmaniasis has been discovered within the last 20 years is the Dominican Republic. Most of the cases are of the diffuse clinical type, which tend to be anergic to the Montenegro skin test, but subclinical or mild cases are apparently common. The responsible agent is a new species of Leishmania and the suspected vector is Lutzomyia cristophei, the only anthropophilic sandfly on the island; the black rat could be a wild reservoir for the parasite. Sporadic indigenous cases have also been reported in Martinique and in Trinidad. On the latter island, no new cases have been found in the last 60 years, and only an enzootic cycle between rodents and marsupials and Lu. flaviscutellata exists there at present; the responsible parasite in this cycle is L. amazonensis or a closely related species. An apparently indigenous case of visceral leishmaniasis has been reported in Guadeloupe but new studies are needed to confirm if this form of the disease is endemic on the island. The sandfly fauna in some of the larger islands is discussed in relation to the existence of possible vectors and the establishment of the disease. In the case of Haiti, there is no reason for human leishmaniasis not to be present as it is in the neighboring Dominican Republic. In Trinidad, the conditions are present for leishmaniasis to become a true zoonosis at any time, produced by L. amazonensis. In Cuba, conditions seem to be favorable for the introduction of cutaneous leishmaniasis in the near future. No predictions can be made at this time for other islands because of lack of information about the existence of the factors required.

Animals↗

Cutaneous leishmaniasis in a sheep.

A case of cutaneous leishmaniasis in a sheep from the Eastern Transvaal is described. The pinna of one ear was swollen and the overlying skin thickened and diffusely encrusted. Histopathological examination of a skin biopsy revealed a diffuse dermal infiltration of macrophages, plasma cells and lesser numbers of eosinophils and neutrophils, as well as a few multinucleated giant cells. Macrophages, particularly in the superficial dermis, contained large numbers of small basophilic bodies morphologically compatible with the amastigote stage of Leishmania spp. Changes in the overlying epidermis included orthokeratotic hyperkeratosis, pseudoepitheliomatous hyperplasia with a focal erosion and crust formation. No attempts were made to culture the organism.

Animals↗

Mechanisms associated with immunoregulation in human American cutaneous leishmaniasis.

Mechanisms possibly involved in the regulation of the immune response were evaluated in 49 patients with American cutaneous leishmaniasis (ACL). The patients were classified on the basis of clinical and histopathological criteria as suffering localized (LCL), mucocutaneous (MCL) or diffuse (DCL) forms of the disease. A significant leishmanial antigen-induced suppression of in vitro mitogen responsiveness was demonstrated in the DCL group, but not in the other two diseases states. Lack of suppressive activity was particularly evident in MCL, this being the group that presented the highest in vivo and in vitro reactivity to the parasite antigens. In fact, a significant inverse correlation was found between the degree of suppression and the antigen-induced lymphocyte proliferative response. In contrast, a mixture of mononuclear cells from MCL patients and normal subjects showed higher that expected responses to mitogen, while this increase was not observed in co-cultures of DCL and normal mononuclear cells. Due to their possible modulatory influences, circulating immune complexes were also evaluated in these patient groups, higher levels being found in MCL and DCL patients than in either LCL or controls. The possible mechanisms involved in the regulation of the immune response to the protozoan in the complex disease spectrum of ACL are discussed in relation to anergy in DCL and hyperresponsiveness in MCL.

Antigen-Antibody Complex↗

Immunohistological investigations in chronic cutaneous leishmaniasis in Saudi Arabia.

The distribution and numbers of IgG-, IgA-, IgM-, and lysozyme-positive cells were investigated by the immunoperoxidase method in paraffin-sections of 13 cases of chronic cutaneous leishmaniasis of low parasite load from Saudi Arabia. The majority of the peroxidase-positive plasma cells contained IgG, whereas the numbers of IgA+ and IgM+ plasma cells were not so numerous. Small groups of squamous epithelial cells showed immunoreactivity for IgG and IgA. Similar positive staining was observed extracellularly in the oedematous upper dermis, in the endothelial cells, and in the perivascular space. The activated macrophages showed strong and diffuse peroxidase staining for lysozyme, whereas epithelioid cells and multinucleated giant cells were negative or had finely granular and considerably weaker staining. It is suggested that humoral immunity also participates in the elimination of the parasites and an immunologically induced necrosis might be responsible for the ulceration of the skin in cutaneous leishmaniasis. It is also assumed that the lysozyme immunoreactivity can be a marker of the activation state of the macrophages.

Adolescent↗

[Lupoid leishmaniasis].

INTRODUCTION: Due to the wide variety of clinical pictures, several terms have been used in the literature reporting cases of lupoid leishmaniasis, including chronic leishmaniasis and recurrent leishmaniasis. CASES: We report three new cases, two of which presented the classical features, and a third one with an unusual distribution of the lesions. DISCUSSION: Lupoid leishmaniasis is a particular evolving form of cutaneous leishmaniasis with characteristic spreading of the initial nodule, leading to a plaque simulating discoid lupus. Leishmaniasis major was identified in all three patients and recognized as the zoonotic leishmaniasis which usually presents as a classical oriental sore. A clinical course to lupoid leishmaniasis is probably related to changes in cell-mediated immunity leading to localized or diffuse lesions.

Adolescent↗

A histopathological study of different clinical forms of cutaneous leishmaniasis.

Biopsy specimens for histopathological study were taken from 15 parasitologically proven cases with different clinical forms of cutaneous leishmaniasis (CL) including two patients with disseminated CL in the form of subcutaneous nodules and satellite papules. The clinical picture of these patients was also reported. The study revealed that the histopathological manifestations were variable, ranging from a diffuse infiltrate in the acute stage to a tuberculoid architecture in the chronic stage. One patient had perineural inflammatory cell infiltrate consisting of lymphocytes, plasma cells and macrophages.

Adult↗

Demonstration of an indomethacin-sensitive mechanism regulating immune reactivity in American cutaneous leishmaniasis patients.

We investigated some aspects of the regulation of the immune response that were sensitive to the effect of indomethacin (INDO), an inhibitor of prostaglandin synthesis, in 84 patients with American cutaneous leishmaniasis (ACL), and in normal controls. The patients were classified on the basis of clinical and histopathological criteria as suffering localized (LCL), mucocutaneous (MCL) or diffuse (DCL) forms of the disease. The responses in vitro to mitogens (PHA and Con A) and leishmanial antigens were evaluated in the presence or absence of INDO. It was found that the drug significantly increased in vitro the mitogenic stimulation by PHA of peripheral blood mononuclear cells from LCL, MCL and DCL patients, but the effect was less evident in the controls. Considering specific responses to leishmanial antigens, we showed that in the presence of INDO, these were significantly increased in LCL patients, but not in MCL or DCL. Also, only in LCL was an inverse correlation found between the initial response to leishmanial antigen and the increase caused by INDO. Significant correlations were found between the INDO-induced enhancement of PHA and Con A responses in the patient groups, but not in the controls. In LCL patients there was a significant correlation between the increases caused by INDO of the mitogen and antigen responses. It can be suggested that an indomethacin-sensitive (prostaglandin dependent) suppressor mechanism operates in LCL patients, that is possibly responsible for the modulation of the immune response against the parasite. In MCL, where this suppressive mechanism is apparently not functional, the response to the parasite is intense, and a possible consequence of this could be tissue damage. Our results indicate, however, that the anergy observed in DCL patients is not due to an involvement of prostaglandins in the suppression of the specific immune response.

Adolescent↗

Leishmaniasis: recognition and management with a focus on the immunocompromised patient.

Leishmaniasis is a protozoan disease whose clinical manifestations depend both on the infecting species of Leishmania and the immune response of the host. Transmission of the disease occurs by the bite of a sandfly infected with Leishmania parasites. Infection may be restricted to the skin in cutaneous leishmaniasis (CL), to the mucous membranes in mucosal leishmaniasis or spread internally in visceral leishmaniasis (VL). In the last 2 decades, leishmaniasis, especially VL, has been recognized as an opportunistic disease in immunocompromised patients, particularly those infected with HIV. Leishmaniasis is characterized by a spectrum of disease phenotypes that correspond to the strength of the host's cell-mediated immune response. Both susceptible and resistant phenotypes exist within human populations. Clinical cutaneous disease ranges from a few spontaneously-healing lesions, to diffuse external or internal disease, to severe mucous membrane involvement. Spontaneously-healing lesions are associated with positive antigen-specific T cell responsiveness, diffuse cutaneous and visceral disease with T cell non-responsiveness, and mucocutaneous disease with T cell hyperresponsiveness. Current research is focused on determining the extent to which this spectrum of host response is genetically determined. In endemic areas, diagnosis is often made on clinical grounds alone including: small number of lesions; on exposed areas; present for a number of months; resistant to all types of attempted treatments; and usually no pain or itching. Multiple diagnostic techniques are available. When evaluating treatment, the natural history of leishmaniasis must be considered. Lesions of CL heal spontaneously over 1 month to 3 years, while lesions of mucocutaneous and VL rarely, if ever, heal without treatment. Consequently, all the latter patients require treatment. Therapy is not always essential in localized CL, although the majority of such patients are treated. Patients with lesions on the face or other cosmetically important areas are treated to reduce the size of the resultant scar. In addition, the species of parasite should be identified so that infection with Leishmania braziliensis and Leishmania panamensis can be treated to reduce the risk of development of mucocutaneous disease. Treating patients with Leishmania and HIV co-infection requires close monitoring for effectiveness of treatment, especially because of the high relapse rates. Proven treatments include: antimonials, pentamidine, amphotericin B, interferon with antimony. Treatments where current clinical experience is too limited include: allopurinol, ketoconazole, itraconazole, immunotherapy, rifampin, dapsone, localized heat, paromomycin ointment and cryotherapy. Investigational treatments include: WR6026, liposomal amphotericin and miltefosine. In addition, vaccines for leishmaniasis are being investigated in clinical trials.

HIV Infections↗

Ocular and periocular manifestations of leishmaniasis in dogs: 105 cases (1993-1998).

The purpose of this retrospective study was to determine the prevalence, type, and prognosis of ocular lesions associated with leishmaniasis in dogs. One hundred and five dogs (24.4% of all cases of leishmaniasis diagnosed during the study period) had ocular or periocular leishmaniasis, and 16 dogs (15.2% of ocular cases) had only ocular lesions and systemic signs were not apparent. Anterior uveitis was the most common manifestation and other prevalent findings included blepharitis and keratoconjunctivitis. Several distinct variations of eyelid lesions were seen including a dry dermatitis with alopecia, diffuse blepharedema, cutaneous ulceration, and discrete nodular granuloma formation. In some cases with keratoconjunctivitis, corneal lesions clinically resembled nodular granulomatous episclerokeratitis. Twenty-seven of the 34 cases with ocular lesions had improvement in signs following systemic antiprotozoal and topical anti-inflammatory therapy, although many cases with anterior uveitis required long-term topical therapy. Response of ocular signs correlated highly with overall, systemic response to therapy. Ophthalmic manifestations of systemic leishmaniasis are common in the dog, and this disease should be considered in the differential diagnosis of most adnexal and anterior segment ocular inflammatory lesions in dogs in endemic areas.

Journal Article↗

Leishmania infantum and Neospora caninum simultaneous skin infection in a young dog in Italy.

Leishmania infantum, the agent of canine leishmaniasis in Mediterranean countries, and Neospora caninum, a recently recognized protozoal pathogen in dogs, were diagnosed in a 9-month-old Argentine Dogo dog. Both skin lesions and neurological signs were present. Histopathology of cutaneous lesions revealed a suppurative, diffuse dermatitis with numerous intracellular protozoa. Serology was positive for both L. infantum (1:640) and N. caninum (1:800). Double-label immunohistochemical staining of skin samples with hyperimmune serum from L. infantum-infected dogs was positive for protozoa within macrophages, while the polyclonal antibody specific for N. caninum showed positive reactions for protozoa in endothelial cells and fibroblasts. Transmission electron microscopy (TEM) confirmed the infection with both protozoa. This is, to the authors' knowledge, the first case of simultaneous infection with L. infantum and N. caninum in a dog. It is possible that the immunosuppressive effects of Leishmania infection or long-term steroid therapy may have been a contributing factor to the development of N. caninum in this dog.

Animals↗