[Apoptosis and cell proliferation in HHV-6 infections. Regulatory mechanisms of p53/bcl-2/ras interactions]

Histiocytic necrotising lymphadenitis (Kikuchi-Fujimoto disease) in Saudi Arabia: clinicopathology and immunohistochemistry

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is a rare entity of uncertain cause that commonly presents as a benign self-limiting disease of unknown origin. The objective of this study was to document the clinical features, mode of presentation, histopathological and immunohisto-chemical (IHC) features of KFD at our institutions since little is known about this disease in our region.

METHODS

We reviewed the histopathological reports of all lymph nodes resected at or referred to King Abdulaziz University Hospital between 1990 and 2003 and King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia between 2000 and 2003. All cases diagnosed as KFD were identified and the histological slides and clinical data were reviewed. IHC was performed for the proliferative marker Ki-67 and the apoptosis-related markers Bcl-2 and p53.

RESULTS

In 2500 lymph node biopsies, 15 cases were diagnosed as KFD. The female to male ratio was 2.7:1. One patient presented with axillary lymphadenopathy and the others presented with cervical lymphadenopathy. Ages averaged 29 years and ranged from 13 to 46 years. There was no recurrence of the lymphadenopathy over 1 to 10 years of follow up. Bcl-2 and p53 were negative and Ki-67 was positive in 11 of 15 cases.

CONCLUSION

The results support earlier findings that KFD is a self-limiting disorder that requires no specific management. We suggest a clinical follow-up for several years. The female predominance was striking. Apoptosis-regulating proteins are not helpful in the diagnosis. KFD usually expressed the proliferation-associated nuclear antigen Ki-67. Increased awareness of KFD will minimize the risk of confusing this entity with malignant lymphoma or other serious conditions.

The p21-Ras signal transduction pathway and growth regulation in human high-grade gliomas

Deregulated p21-Ras function, as a result of mutation, overexpression or growth factor-induced overactivation, contributes to at least 30% of human cancer. This article reviews the potential role of the p21-Ras family of GTPases in the regulation of growth of high-grade gliomas and describes how targeting this oncoprotein clinically may provide a novel strategy to counteract glioma proliferation. The application of strategies directed at selectively opposing the deregulated signal transduction pathway of high-grade gliomas may be of potential therapeutic benefit and may offer a whole new arsenal of antineoplastic agents to be included in the multimodal treatment of these challenging neoplasms.

Human herpesvirus-6 (HHV-6)-associated necrotizing encephalitis in Griscelli's syndrome

We report a male caucasian German pediatric patient of no Arab or Mediterranean ancestry with virus associated CNS lesions in Griscelli's syndrome (GS; McKusick No. 214450). The boy presented with recurrent infections, and meningitis with subsequent progressive signs of increased intracranial pressure leading to death at 32 weeks of age. At autopsy, various sites of the CNS revealed necroses in gray and white matter. CNS histology revealed numerous and massive predominantly perivascular CD8 positive lymphohistiocytic infiltrates. These findings were associated strictly with the presence of human herpesvirus-6 (HHV-6) genome or the HHV-6 specific late antigen H-AR 3, found in neurons, oligodendrocytes, and astrocytes. The search for HHV-6 replication dependent antigen, HHV-7 DNA, CMV, adenovirus, Coxsackie B1, B2, and B4-antigens, and mycobacteria was not successful. Detection of viruses was attempted using immunohistochemistry, in situ hybridization or nested polymerase chain reaction, respectively. Lymphocyte typing was carried out immunohistochemically. In GS, virus induced CNS damage does not seem to require necessarily active virus replication. It may also appear as a consequence of an immune reaction triggered by antigen expression.