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Results for “Leishmaniasis, Diffuse Cutaneous”

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PubMed1993

Resistance of mice to experimental leishmaniasis is associated with more rapid appearance of mature macrophages in vitro and in vivo.

Resistance to murine leishmaniasis has been related to the propagation of specific Th cell subsets (Th1 and Th2). This study shows that there are differences between resistant and susceptible mice in the initial myelomonocytic infiltrate, which precede the specific T cell response. After subcutaneous injection of 2 x 10(7) Leishmania major into footpads of resistant C57Bl/6 and susceptible BALB/c mice we performed immunohistochemical studies on the infiltrate. Two days after infection the percentage of more mature, F4/80-positive macrophages in the lesion increased faster in C57Bl/6 mice (63%) than in BALB/c mice (29%). The same strain-specific differences were observed after infection of corresponding strains of athymic mice (57.2% in C57Bl/6 nu/nu; 33.6% in BALB/c nu/nu), thus excluding a T cell-controlled phenomenon. After 1 wk the infiltrate in susceptible mice began to reveal significantly more cells containing MRP14, which is expressed by granulocytes and less mature monocytes but not by mature macrophages. No corresponding differences were found between athymic strains, suggesting that at this point organization of the infiltrate falls under control of protective T cells. In bone marrow cultures of BALB/c and C57Bl/6 mice, the percentage of F4/80-positive macrophages was also increasing faster in C57Bl/6 mice than in BALB/c mice. Increased expression of the F4/80 Ag was associated with higher leishmanicidal activity of C57Bl/6 macrophages. MRP14-positive bone marrow cells on the other hand were rarely infected by parasites. We suggest 1) that the earlier appearance of leishmanicidal macrophages in lesions of C57Bl/6 mice could influence propagation of either Th1 or Th2 cells by reduction of parasite load or by differential secretion of decisive cytokines and 2) that the diffuse accumulation of granulocytes and inflammatory monocytes in susceptible mice facilitates spread of disease.

Animals↗

PubMed1988

A new method for diagnosis of Chagas' disease: diffusion-in-gel enzyme-linked immunosorbent assay.

The diffusion-in-gel enzyme-linked immunosorbent assay (DIG-ELISA) for antibodies to Trypanosoma cruzi was evaluated using formalinized epimastigotes as antigen. The results obtained by DIG-ELISA were compared with those obtained with the indirect hemagglutination test. The results of the DIG-ELISA showed that the reaction zone diameters obtained with sera from individuals with past or present exposure to T. cruzi were significantly greater than those obtained with normal human sera. All the sera from Chagasic individuals had a positive reaction in the test, whereas sera from normal individuals and individuals with toxoplasmosis or cutaneous leishmaniasis had a negative result. A close correlation was observed between the reaction zone diameters and antibody concentration (expressed as log2 of the serum dilution). Excellent correlation was observed between results obtained by the 2 serological tests. The data suggest that the DIG-ELISA is a promising serological test for measuring antibodies to T. cruzi.

Antibodies, Protozoan↗

PubMed2005

Late cutaneous metastases in C3H SCID mice infected with Leishmania amazonensis.

The biological behavior of Leishmania amazonensis in the mammalian host is highly variable, resulting in local to diffuse cutaneous lesions that sometimes metastasize. Inflammation and, more specifically, CD4+ T cells have been shown to enhance metastases in mice infected with L. amazonensis, suggesting that the process may be lymphocyte mediated. However, we document, in this study, the development of multiple cutaneous metastases in C3H SCID mice infected with L. amazonensis. This shows that functional T and B cells are not required for metastases to occur.

Animals↗

PubMedDate not supplied

[Evolution towards generalization and cancer of a muco-cutaneous leishmaniasis treated with corticoids. (Report of a Chadian case) (author's transl)].

The authors present a case of muco-cutaneous leishmaniasis in the Republic of Chad. In that case, a long duration treatment with corticoids entailed the generalization of the disease in the form of a secondary kala-azar and the appearance of a histiocytosarcoma on the scar left by the oriental sore. Comments on the pathogenesis of leishmaniasis are then exposed.

Adrenal Cortex Hormones↗

PubMed1984

Cutaneous leishmaniasis: immune complex formation and necrosis in the acute phase.

Twenty biopsies of lesions of cutaneous leishmaniasis were classified according to the mechanism of parasite elimination, on the basis of macrophage activation (five cases) or macrophage lysis (15 cases). The immunoperoxidase technique was used to demonstrate free Leishmania antigen, immunoglobulins, complement, lysozyme, C-reactive protein, beta-lipoprotein, alpha 1-antitrypsin, alpha 2-macroglobulin, plasminogen and factor VIII, which were quantitated and comparatively assessed. The fall in the parasite load during the course of the infection was associated with rising levels of IgG, IgM and IgE, and of the complement components of the classical pathway. Macrophage lysis supervened when there was an approximate equivalence of antigen and antibody, and was associated with the deposition of immune complex components. Lysis of the acute focal type (C response) was accompanied by a massive liberation of free Leishmania antigen, followed by a fall indicative of parasite elimination. The lysis of small numbers of macrophages scattered diffusely in the lesion, which was slow to reach completion (B response), was less effective and immunologically closer to the non-lytic (A) response. A terminal fall of the immunological factors other than the globulins, suggestive of resolution, was observed mainly in the C response. Lymphocytes may be important in macrophage activation associated with the macrophage A response and in the later stage of the B and C responses. However immunologically induced host-cell lysis is more important than macrophage activation for the elimination of Leishmania in the acute stage of most skin lesions. It is associated with, and may be caused by, the formation in situ of immune complexes of Leishmania antigen and antibody at an appropriate ratio.

Antigen-Antibody Complex↗

PubMedDate not supplied

[The isolation and immunochemical study of Leishmania antigens].

The authors describe a procedure for producing the antigen by using a promastigotic suspension of the high-virulent inoculative strain Leishmania major. A Leishmania culture medium was improved to enhance the yield of parasites up to 1-3 billion cells in a flask. The grown culture was washed off with isotonic sodium chloride solution, from the medium residues and concentrated up to 1 billion cells per ml of the cvolume. The cell concentrate contained no rabbit blood additive, as evidenced by the gel double diffusion test. The combinations of destruction via multiple freezing-unfreezing or lyophilization, followed by ultrasound treatment were found to be the best modes of promastigotic disintegration. The antigenic suspension generally displayed 3-5 precipitation lines with hyperimmune rabbit sera and 1-3 precipitation lines with sera from the infected animals. The number of precipitation lines is higher in the suspension from the high-virulent Leishmania strains. Fractions of protective antigens have not been detected so far.

Animals↗

PubMed2004

[Monitoring of canine leishmaniasis in northern Italy: an update from a scientific network].

Canine leishmaniasis (CanL) due to Leishmania infantum is a disease of great veterinary importance and a serious public health problem. In humans, L. infantum causes visceral (VL) and cutaneous leishmaniasis (CL) and the distribution of VL overlaps that of CanL. Currently, VL is considered by WHO as an emerging zoonosis in southern Europe. The dog is the only domestic reservoir of the infection and phlebotomine sandflies are the only proven vectors of leishmaniasis for dogs and humans. CanL is endemic in Italy, particularly in central and southern regions, including islands. Until 1983, all regions of northern Italy but Liguria and some territories of Emilia Romagna were considered free from CanL. From early '90s new stable foci of CanL have appeared, most of them located within classical endemic areas including territories of Emilia Romagna, Tuscany, Umbria, Marche, and Abruzzi regions. But the most relevant aspect, from an epidemiological point of view, has been the appearance of stable CanL foci in northern Italy, namely in Veneto and Piedmont regions. In these two foci, entomological surveys showed the presence of P. perniciosus and of a second phlebotomine vector, P. neglectus, which may have played a role in the CanL diffusion in some parts of northern Italy. Furthermore, in these areas, autochthonous human VL cases have occurred. There is therefore a realistic risk that CanL infection could rapidly spread through northern latitudes and a surveillance activity is strongly needed. For this reason, in October 2002, thanks to the collaboration and support of Intervet Italia, the network "LeishMap" was created, with the main purpose of monitoring the spread of CanL and vectors in northern Italy. LeishMap consists of scientific and sanitary institutions with proven experience both in field surveys and diagnostic methodologies on CanL and phlebotomine vector. It is organised in 4 Operational Units (OU), represented by researchers of the Veterinary Faculties of the University of Bologna, Padua, Milan and Turin, under the scientific coordination of the MIPI Department, ISS of Rome and with the collaboration of private and public veterinarians operating in the regions under study. During the first year of activity, each OU was involved in the serological and entomological surveillance of several territories in the respective regions, where recent autochthonous CanL cases were registered. The studies have involved five regions, namely Valle D'Aosta, Piedmont, Lombardia, Veneto, Trentino-Alto Adige and Emilia Romagna. In the Symposium 6 of this Congress we report detailed results of a retrospective analysis of data concerning CanL and vectors in northern Italy till 2002 and the preliminary results of 2003 on the seroprevalence rates observed in foci studied and on the entomological surveys carried out. In summary, the results outlined that already known foci of CanL are expanding from the original sites. Several new foci have been identified and many others are at high risk of evolving toward a stable endemicity. P. perniciosus has been found in all but one the suspected new foci. In Emilia Romagna region P. perfiliewi was identified in 2 areas and in one was the only species present. The occurrence of P. neglectus was confirmed in three regions, Veneto, Lombardia and Piedmont. In conclusion, from the 2002-2003 LeishMap activities it appears that further monitoring activities are necessary to identify new endemic foci of CanL, this representing the prerequisite for the implementation of programs for leishmaniasis control in northern Italy.

Animals↗

PubMedDate not supplied

[Cutaneous leishmania in HIV patient in Ouagadougou: clinical and therapeutic aspects].

BACKGROUND: Immune suppression cause by HIV infection is a risk factor in the progression of leishmania diseases. In Burkina Faso atypical clinical presentations of leishmaniases have been observed among people living with HIV. The goal of this study was to describe clinical and evolutionary aspects of cutaneous leishmania and HIV co-infection among patients followed at Ouagadougou University Hospital. PATIENTS AND METHODS: This 16-month prospective study was carried out from January 2003 to April 2004 among HIV-seropositive patients with a diagnosed cutaneous leishmania infection. At baseline, infection and lesions were classified. Clinical diagnosis of cutaneous leishmania depended on finding parasites by microscopy in smears or tissue biopsies. Histological examinations were done if clinical and parasitological diagnosis were not concordant. Treatment consisted of three 21-day rounds of pentavalent antimonial, (Glucantime(R)). Clinical evolution was monitored at the end of each treatment round. RESULTS: Thirty-two HIV-1 positive patients (16 women and 16 men) were included. Mean age was 35.5 (10-67 years old). Leishmania lesions had been evolving, on average, for 12 weeks. Eleven patients were taking HAART and 21 patients were taking cotrimoxazole prophylaxis against opportunistic infections. Cutaneous lesions were found: in the face (15 cases), torso (18 cases), upperlimbs (26 cases) and lower-limbs (28 cases). Observed clinical forms were: papulo-nodular (9 cases), ulcerative (14 cases), infiltrative (12 cases), lepromatous and diffuse (15 cases), psoriasis-like (5 cases), cheloid, histioid or kaposi-like (1 case each). Some patients presented more than one clinical form. Prognosis was satisfactory in 24 patients after the first treatment. Twelve patients relapsed after the first treatment, among those 10 were only taking cotrimoxazole. At the end of the third treatment, 24 patients were cured, 3 died and 5 were lost to follow-up. CONCLUSION: Clinical polymorphism of cutaneous leishmania has been observed in HIV-patients, thereby increasing the risk of differential diagnosis.

AIDS-Related Opportunistic Infections↗

PubMed1983

Leishmania species: comparative ultrastructure of experimental nodules and diffuse human cutaneous lesions in American leishmaniases.

Experimental nodules of American leishmaniases were obtained by inoculating 0.1-1 x 10(5) amastigotes into the dorsum of the hindpaws of golden hamsters and of C57Bl/6J mice. The amastigotes were obtained by biopsy of lesions in six human cases of cutaneous leishmaniases and were serially maintained in golden hamsters and in a fetal calf serum-containing medium. Human nodules were obtained by biopsy from several patients with diffuse cutaneous leishmaniases, always prior to treatment. Within the same host species, no ultrastructural differences were seen in the tissue response to isolates of Leishmania mexicana, L. brasiliensis, or L. garnhami, nor were there differences between the host species in response to a particular isolate of the genus Leishmania. The typical inflammatory response was a macrophage granuloma with abundant polymorphonuclear neutrophils, some eosinophils, and plasma cells. Simple human cutaneous leishmanial lesions, as well as experimental nodules in regression, show many fibroblasts, much collagen fiber, but very few parasites. In typical lesions, parasites occurred within macrophage phagolysosomes, within distended lacunar cells, and in the intercellular spaces. Leishmaniae strongly adhered to parasitophorous vacuoles by a site of their plasma membrane directly opposite the flagellum, and the host cell cytoplasm close to the adherence site became highly vacuolated. In most cases the intra- and extracellular parasites show normal morphology, which suggest the inability of phagocytic cells to attack them.

Adolescent↗