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Lacaziosis is a cutaneous chronic mycosis caused by Lacazia loboi. Macrophages are important cells in the host immune response in fungal infections. The macrophage population exhibits strong plasticity that varies according to the stimuli in the microenvironment of lesions M1 profile promotes a Th1 pattern of cytokines and a microbicidal function and M2 is related to Th2 cytokines and immunomodulatory response. We investigated the population of M1 and M2 polarized macrophages in human cutaneous lesions. A total of 27 biopsies from human lesions were submitted to an immunohistochemistry protocol using antibodies to detect M1 and M2 macrophages (Arginase-1, CD163, iNOS, RBP-J and cMAF). We could observe high number of cells expressing Arginase1, CD163 and c-MAF that correspond to elements of the M2 profile of macrophage, over iNOS and RBP-J (elements of the M1 profile). The results suggest a predominant phenotype of M2 macrophages, which have an immunomodulatory role and probably contributing to chronicity of Lacaziosis. Electronic supplementary material The online version of this article (10.1007/s11046-020-00450-z) contains supplementary material, which is available to authorized users.

Lobomycosis is a disease that is endemic to the Amazon rainforest and is caused by the still uncultured fungus Lacazia loboi. This disease occurs in loggers, farmers, miners, fishermen, and persons living near coastal rivers of this region. We report 6 soldiers in Colombia in whom lobomycosis developed after military service in the Amazon area. The patients had nodular and keloid-like lesions on the face, neck, trunk, and limbs. The duration of illness ranged from 2 years to 15 years. The initial diagnosis was leishmaniasis on the basis of clinical manifestations and direct smear results, but biopsies confirmed the final diagnosis of lobomycosis. Treatment with surgical excision, itraconazole and clofazimine was satisfactory. However, the follow-up time was short. Healthcare professionals responsible for the diagnosis and treatment of skin diseases need to be able to recognize the clinical signs of lobomycosis and differentiate them from those of cutaneous leishmaniasis.

Lacaziosis is a cutaneous mycosis caused by the fungus Lacazia loboi, described in different countries of Latin America and prevalent in the Amazon region. The ineffective immune response against the agent seems to be related to a Th2 pattern of cytokines. There are few reports exploring elements of the humoral response in these lesions. Our aim was to investigate some elements focusing on B cells, plasma cells and local expression of IgG and IgM antibodies. Forty skin biopsies of lower limbs were selected. The diagnosis of lacaziosis was based on direct mycological examination and histological analysis. The visualization of fungal cells was improved by using Gridley’s staining. An immunohistochemical protocol was performed to detect the expression of B cells, plasma cells, IgG and IgM. A double staining was performed to explore the presence of yeasts in the cytoplasm of keratinocytes, using an anti-AE1 AE3 antibody over Gridley’s staining. The inflammatory infiltrate consisted of macrophages, multinucleated giant cells, lymphocytes, and fibrosis. Fungal cells were frequent in the stratum corneum and in both, the dermis and, in 50% of the specimens, also in the epidermis. Cells expressing IgG were more abundant when compared to cells expressing IgM. B cells and the presence of IgG might indicate that the humoral response promotes a Th2 immune response resulting in an anti-inflammatory phenotype. Our results lead us to suggest a possible role of B cells and immunoglobulins in the mechanisms of lacaziosis pathogenesis.

Our findings could stimulate study of public health implications of diseases caused by this fungus., Cutaneous granulomas in dolphins were believed to be caused by Lacazia loboi, which also causes a similar disease in humans. This hypothesis was recently challenged by reports that fungal DNA sequences from dolphins grouped this pathogen with Paracoccidioides brasiliensis. We conducted phylogenetic analysis of fungi from 6 bottlenose dolphins (Tursiops truncatus) with cutaneous granulomas and chains of yeast cells in infected tissues. Kex gene sequences of P. brasiliensis from dolphins showed 100% homology with sequences from cultivated P. brasiliensis, 73% with those of L. loboi, and 93% with those of P. lutzii. Parsimony analysis placed DNA sequences from dolphins within a cluster with human P. brasiliensis strains. This cluster was the sister taxon to P. lutzii and L. loboi. Our molecular data support previous findings and suggest that a novel uncultivated strain of P. brasiliensis restricted to cutaneous lesions in dolphins is probably the cause of lacaziosis/lobomycosis, herein referred to as paracoccidioidomycosis ceti.

Lobomycosis is a subcutaneous mycosis of chronic evolution caused by the Lacazia loboi fungus. Its distribution is almost exclusive in the Americas, and it has a particularly high prevalence in the Amazon basin. Cases of lobomycosis have been reported only in dolphins and humans. Its prevalence is higher among men who are active in the forest, such as rubber tappers, bushmen, miners, and Indian men. It is recognized that the traumatic implantation of the fungus on the skin is the route by which humans acquire this infection. The lesions affect mainly exposed areas such as the auricles and upper and lower limbs and are typically presented as keloid-like lesions. Currently, surgical removal is the therapeutic procedure of choice in initial cases. Despite the existing data and studies to date, the active immune mechanisms in this infection and its involvement in the control or development of lacaziosis have not been fully clarified. In recent years, little progress has been made in the appraisal of the epidemiologic aspects of the disease. So far, we have neither a population-based study nor any evaluation directed to the forest workers.

We report 1 case of lobomycosis caused by Lacazia loboi in a fisherman and 1 case of lobomycosis-like disease in a bottlenose dolphin (Tursiops truncatus) along the coast of Venezuela. These findings suggest that the marine environment is a likely habitat for L. loboi and a reservoir for infection.

To the Editor: Jorge Lobo disease (lacaziosis) is a chronic deep mycosis for which prognosis is good in terms of survival but unclear in terms of regression of the lesions (1). No involvement of internal organs or mucous membranes is observed. The causative agent is Lacazia loboi (2), a fungus of uncertain phylogeny, which causes an inflammatory infiltrate accompanied by the formation of a granuloma in which giant cells phagocytose a larger number of fungi (3,4). Pecher and Funchs suggested that patients with lacaziosis have a cellular immunodeficiency (5). The disease is more frequent in men and persons 21–40 years of age. It is found exclusively in Latin America; only 1 case has been diagnosed in Europe, and that was due to accidental contamination with material from a dolphin (4). Trauma and injuries or sites of insect bites facilitate penetration of the fungus. Lesion progression is slow, with new lesions arising by contiguity with other lesions or through the lymphatic route (6,7). Clinically, lacaziosis manifests as keloidal lesions of solid consistency and variable size that contain small scales and crusts (6). The lesions are most frequently located in the auricle and on the upper and lower limbs. Cutaneous dissemination of the disease is observed in a relatively small number of cases. We describe a patient with Jorge Lobo disease. The patient was a 59-year-old man, a storeroom employee, who was seen at the Tropical Medical Center in Belem, Brazil, in April 2004. A papula had developed near his right knee in 1992 after a wood splinter had penetrated the skin. The lesion increased in size, and a histopathologic diagnosis of Jorge Lobo disease was made. The lesion was then surgically removed. Approximately 2 years later, the lesion recurred. The patient then went to a dermatology service and was treated with clofazimine, after which the lesion disappeared. However, the lesion reappeared 1 year later. HIV serologic analysis was performed in 2002, and the results were positive. The patient then began treatment for HIV infection. He is currently being monitored at the specialized referral unit in Belem. He does not have any opportunistic infections and is not taking any antiretroviral drugs. The patient came to the dermatology service of the Tropical Medical Center, where dermatologic and histopathologic examinations were conducted and CD cell counts and HIV viral load were measured. Dermatologic aspects of the lesion included an erythematous-infiltrated, hypertrophic plaque with a verrucous surface ≈4 cm long in the distal third of the medical aspect of the right thigh (Figure). A punch biopsy specimen of brown smooth skin 0.35 cm in diameter in an epidermal disk was fixed in formalin. Microscopy of skin sections containing epidermis showed compact keratinization, parakeratotic foci, and irregular hyperplasia with a pseudoepitheliomatous area. A highly dense, nodular, diffuse inflammatory infiltrate was observed at all levels of the dermis. It consisted of macrophages and numerous multinucleated cells, most of them of the foreign body type. Fibroplasia was also noted. Abundant, round parasitic elements surrounded by a double membrane and containing a basophilic nucleus were found in tissues, as well as other anucleated, intracellular, and free parasites that formed chains of >2 cells (Figure A1). Jorge Lobo disease was diagnosed. Laboratory results showed 146 CD4 cells/μL, 251 CD8 cells/μL, a CD4:CD8 ratio of 0.42, and 60,000 copies of HIV viral RNA/mL. Figure Erythematous-infiltrated, hypertrophic plaque with a verrucous surface ≈4 cm long in the distal third of the medical aspect of the right thigh of the patient. Since a cytotoxic response is observed in Jorge Lobo disease (7), HIV infection may increase the susceptibility to infection with L. loboi. Patients with AIDS show a predisposition to diverse fungal infections that classically affect different organs and systems. An association between Jorge Lobo disease and AIDS has not been reported. However, since Jorge Lobo disease is restricted to specific areas of the world and the number of AIDS cases is increasing, especially in Latin America, a possible correlation between HIV infection and Jorge Lobo disease should be considered because of the associated cellular immunodeficiency. The patient showed no signs of other opportunistic infections classically associated with AIDS, and he was not taking any antiretroviral drugs. His initial infection manifested as cutaneous lesions that occur in Jorge Lobo disease. Despite the cellular immunodeficiency, we did not observe atypical dissemination of the lesions. Further studies should be conducted to evaluate the relationship between the cellular immunosuppression of AIDS and secondary infection with L. loboi. In addition, epidemiologic studies are needed to determine the association of AIDS with Jorge Lobo disease.