Rhinoscleroma pathogenesis: The type K3 capsule of Klebsiella rhinoscleromatis is a virulence factor not involved in Mikulicz cells formation.

Rhinoscleroma is a human specific chronic granulomatous infection of the nose and upper airways caused by the Gram-negative bacterium Klebsiella pneumoniae subsp. rhinoscleromatis. Although considered a rare disease, it is endemic in low-income countries where hygienic conditions are poor. A hallmark of this pathology is the appearance of atypical foamy monocytes called Mikulicz cells. However, the pathogenesis of rhinoscleroma remains poorly investigated. Capsule polysaccharide (CPS) is a prominent virulence factor in bacteria. All K. rhinoscleromatis strains are of K3 serotype, suggesting that CPS can be an important driver of rhinoscleroma disease. In this study, we describe the creation of the first mutant of K. rhinoscleromatis, inactivated in its capsule export machinery. Using a murine model recapitulating the formation of Mikulicz cells in lungs, we observed that a K. rhinoscleromatis CPS mutant (KR cps-) is strongly attenuated and that mice infected with a high dose of KR cps- are still able to induce Mikulicz cells formation, unlike a K. pneumoniae capsule mutant, and to partially recapitulate the characteristic strong production of IL-10. Altogether, the results of this study show that CPS is a virulence factor of K. rhinoscleromatis not involved in the specific appearance of Mikulicz cells.

Rinoscleroma. Una entidad a considerar en la rutina diaria del patólogo / Rhinoscleroma: an entity to consider in the daily routine of the pathologist

El rinoscleroma es una enfermedad infrecuente en España, pero endémica en ciertas regiones del mundo. Se presenta como una enfermedad inflamatoria crónica granulomatosa progresiva que típicamente compromete la mucosa nasal, pero puede presentarse en otras localizaciones del tracto aereodigestivo superior. Su diagnóstico se apoya en estudios de imagen y en hallazgos clínicos como la deformidad nasal o la obstrucción de la vía aérea con disnea, disfonía y estridor respiratorio. Sin embargo, usualmente requiere confirmación histopatológica, aunque la detección de la bacteria Klebsiella rhinoscleromatis en etapas iniciales sería definitivo. Esta es una enfermedad que precisa un grado alto de sospecha y que debe tenerse en cuenta en la actualidad ante el incremento de la inmigración a nuestro medio desde regiones endémicas (AU)

The rhinoscleroma is a rare pathology in Spain, but endemic in certain regions of the world. It presents as a chronic, progressive and granulamatous entity, typically compromises the nasal mucosa, but it can occur in other locations of the upper aerodigestive tract. The diagnosis is based on clinical findings as nasal deformity or obstruction of the airways with dyspnoea, dysphonia and stridor and it relies on imaging techniques. However, ususally requires confirmatory histopathological diagnosis although detecting the bacterium Klebsiella rhinoscleromatis not in advance stages would be definitive. This is a disease that accurate a high degree of suspicion and should be taken into consideration currently due to the increase of immigration to our country from endemic regions (AU)

Rhinoscleroma in an immigrant from Egypt: a case report.

Rhinoscleroma is a chronic indolent granulomatous infection of the nose and the upper respiratory tract caused by Klebsiella rhinoscleromatis; this condition is endemic to many regions of the world including North Africa. We present a case of rhinoscleroma in a 51-year-old Egyptian immigrant with 1-month history of epistaxis. We would postulate that with increased travel from areas where rhinoscleroma is endemic to other non-endemic areas, diagnosis of this condition will become more common.

[The specific features of the pathological morphology and pathogenesis of scleroma: morphological, histochemical, and electron microscopic studies].

The specific features of the pathological histology of scleroma have been continuously studied at the Pathology Department of the Lvov Medical University since 1945. A total of 1025 biopsy specimens from 656 patients with scleroma were examined. Along with diverse dystrophic and metaplastic changes in the epithelial coverings, which were affected by scleroma, there were its original inflammatory enlargements that were likely to play an active part in the inflammatory process. Abundant formation of fibrous structures in the granulation tissue undoubtedly reflects the protective functioning of an organism. Impaired innervation led not only to ageusia and anosmia in patients with scleroma; loss of nervous communications with the organism is very likely to affect the course of the pathological process to either degree. Electron microscopy provided more evidence for the presence of endobiosis in scleroma and the inability of drugs to affect directly the Frish bacillus due to its secreted mucopolysaccharide the composition of which is little studied.

Grave afectación laringotraqueal secundaria a rinoescleroma por Klebsiella pneumoniae ssp. ozaenae / No disponible

No disponible

Rhinoscleroma: a French national retrospective study of epidemiological and clinical features.

BACKGROUND: Rhinoscleroma (RS) is a rare, chronic, granulomatous disease of the upper respiratory tract that is associated with infection with Klebsiella rhinoscleromatis. RS is more common in certain geographic regions than in others, but other risk factors and the pathogenesis of RS remain unclear. METHODS: We sent a standardized questionnaire to all pathologists and otolaryngology specialists in French University Hospitals and asked whether they had seen patients with RS in the previous 16 years (1990-2005). We then retrospectively reviewed the files of all patients identified. RESULTS: We collected 11 cases of RS, with a median patient age at diagnosis of 35.7 years (range, 5-72 years). The 3 patients with a familial history of RS presented with early-onset forms of RS; 1 had an uncommon aggressive presentation of the disease with ischemic stroke. Two unrelated consanguineous families were identified, 1 of which included 2 affected siblings. Two patients with sporadic disease were positive for HIV infection. All patients were living in France, but most were immigrants from areas where RS is endemic (North Africa, 3 of the 11 patients; West Africa, 4 patients; and Turkey, 1 patient). The probable duration of exposure to K. rhinoscleromatis in endemic areas varied widely: 0-28 years. Clinical features and outcome also varied considerably among cases. Biopsies had been performed for all patients and revealed granulomas containing Mikulicz cells. Cultures of biopsy tissue were positive for K. rhinoscleromatis in 5 of the 11 cases. Prolonged antibiotic treatment was administered to all patients, as follows: ciprofloxacin (7 patients), third-generation cephalosporins (2), tetracycline (2), and clofazimine (2). Eight of the 11 patients did not experience relapse during extended periods of follow-up (1.3-12 years). Relapses in 3 patients were confirmed by a second biopsy. CONCLUSIONS: The occurrence of early-onset RS in multiplex and/or consanguineous families suggests that genetic control of the host response to K. rhinoscleromatis may be involved in the pathogenesis of RS in endemic areas.

Doenças granulomatosas da laringe / Granulomatous diseases of the larynx

Realizamos uma revisäo sobre as principais doenças granulomatosas que podem acometer a laringe, devido à grande ocorrência dessas afecçöes no Brasil e em outros países de clima tropical e subtropical. Ressaltamos os aspectos histopatológicos para o seu diagnóstico, assim como o seu tratamento.

Isolated subglottic scleroma.

Scleroma, more commonly known as rhinoscleroma, is a progressive, chronic, granulomatous disease of the respiratory tract and adjacent tissues. Early diagnosis and prolonged therapy are critical in avoiding its late sequelae. We describe an unusual case of scleroma presenting as worsening chronic lung disease. The variety of clinical presentations and treatment modalities is reviewed.

Rinoescleroma / Rhinoescleroma

El rinoescleroma es una enfermedad rara, granulomatosa, crónica, causada por Klebsiella rhinoscleromatis, la cual afecta predominantemente el tracto respiratorio superior, siendo más frecuente en países subdesarrollados