[Neurofibromatosis (NF1) and neuroleprosy: immunoreaction against pathologic Schwann-cells. Physiopathogenetic observations]. / Neurofibromatosi (NF1) e neurolebbra: immunoreazione verso cellule di Schwann patologiche. Considerazioni fisiopatogenetiche.

BACKGROUND: We reviewed the literature evaluating the immune reaction in neurofibromatosis (NF1) and neuroleprosy, so as to underline the immunopathegenetic parallelism and the possible therapeutic implications regarding the treatment of these two disorders. In particular we evaluated the systemic modifications and the local fibrotic events that lead to nerve damage in NF1 and complete neuronal destruction as in leprosy. METHODS: With the above aim in mind we studied the histology, histochemistry and immunohistochemistry (Schwann cells and immunoglobulins) of four plexiform neurofibroma, one common neurofibroma and one case of borderline neuroleprosy (BT). RESULTS: Two plexiform neurofibromas showed an evident immune reaction that was antibody mediated with numerous IgG; the remaining neurofibromas represented other stages of disease evolution and disease quiescence and thus showed a scarce immune reaction with a reduced presence of immunoglobulins. All the neurofibromas showed the presence of fibrous bundles. In the case of neuroleprosy (BT), the immune reaction was modest, immunoglobulins were present and fibrotic transformation on neuronal fibers was observed. CONCLUSIONS: Being that pathologic Schwann cell are the site of immune reactions that can become abnormal (at times with autoimmune reactions), clinical as well as biochemical surveillance of leprous neuropathy and NF1 could allow for a timely modification of the abnormal reaction with selective immunomodulators. The inactivation of the mycobacterial RNA polymerase or of the NF1 gene could offer hope for controlling disease activity and disease evolution of the two disorders.

Tumour suppressor genes, immunology and local manifestations of neurofibromatosis phenotypes.

Research on Neurofibromatosis (NF) has been directed at understanding what determines disease quiescence, exacerbation, and the possible malignant evolution. Studies on NF have examined the role of genetic oncosuppression in the evolution of the defence against the non-self. Paraffin fixed specimens of benign and malignant neoplasia, occurring in patients with NF1 and NF2, were tested for the presence of p53: a reliable marker of genetic oncosupression. The wild type variant of p53 is expressed in malignant neoplasia, and is usually not expressed in benign tumors. Contrariwise, an immune reaction it is seen in benign tumors and is practically absent in malignant tumors. Evidence of protein p53 in the various malignant neoplasias studied by our group seems to reflect the up-regulation on the oncosuppresive genetic potential that occurs while there is a lack of immunological defence. In the presence of an immunological defence, the expression p53 is normally not seen e.g. plexiform neurofibromas. The evolution of the various neoplastic types here reported was the same as that reported by current clinical and experimental models: the cell's defective genes are no longer suppressed and after activation the genes undergo initiation, promotion, and the cell sustains inflammatory-immune reactions that lead to fibrosis; what follows is a variable period of apparent quiescence. Severe pathogenic stimuli may act on predisposed cells and deteriorate pre-existing genetic damage, casting the cell into a phase of dysplastic or neoplastic proliferation that overcomes the body's defences. Hope for future therapy lies in the development of drugs that can either mimic the immune system or the proteins encoded by the oncosuppressor genes.

Immunological and clinical surveillance in Recklinghausen's neurofibromatosis (NF1).

Neurofibromatosis evolution is described in relation to the factors that may favour its expansion and immune modifications. NF1 monitorization should employ periodic clinical and immune surveillance. Such an approach would allow the application of immunomodulating treatment (e.g. adapted therapy) only when indicated, thereby reducing its duration and potentiating its efficacy.

[Local immune response in neurofibromatosis type 1 and type 2]. / L'immunoreazione locale nelle neurofibromatosi di von Recklinghausen e del neurinoma bilaterale del nervo acustico.

Neurofibromatosis, in all its variant forms, is a hereditary disease characterized by dysplasia, neoplasia, and the tendency to expand and undergo malignant transformation. We underline the presence of chronic inflammation and of immunologic interdependency. The immune reactions against the non-self have been investigated histologically in light of the concepts of immunosurveillance and immunotolerance. Such investigations would ameliorate subsequent studies and favour the employment of immunomodulatory treatments.

[Immune reaction in von Recklinghausen's neurofibromatosis]. / La reazione immunitaria nelle neurofibromatosi di von Recklinghausen.

A multidisciplinary study was performed on cases of neurofibromatosis to highlight the immunological reaction using broad-spectrum hematic tests and multiphase evaluation together with clinical and instrumental monitoring. The aim of the study was to focus attention on this rare disease and prompt further sequential immunological studies. A greater knowledge of the disease would allow the promising potential of new drugs to be exploited, in particular selective immunomodulatory drugs, in the hope of controlling the symptoms of disease (and overcoming further obstacles to the surgical removal of any neurofibromas that the patient wishes.