Case report: Kikuchi-Fujimoto disease: unveiling a case of recurrent fever and enlarged cervical lymph nodes in a young female patient with a literature review of the immune mechanism

The inflammatory response to viral infection is an important component of the antiviral response, a process that involves the activation and proliferation of CD8+ T, CD4+ T, and dendritic cells; thus, viral infection disrupts the immune homeostasis of the organism, leading to an increased release of inflammatory factors. Kikuchi-Fujimoto disease (KFD) is an inflammatory self-limited disorder of unknown etiology, and it is generally believed that the pathogenesis of this disease includes two aspects: viral infection and autoimmune response. Various immune cells, such as CD8+ T lymphocytes, CD4+ T lymphocytes, and CD123+ plasmacytoid dendritic cells, as well as the cytokines they induce and secrete, such as interferons, interleukins, and tumor necrosis factors, play a crucial role in the pathogenesis of KFD. In this article, we present a case study of a young female patient from China who exhibited typical symptoms of lymph node inflammation and fever. The diagnosis of KFD was confirmed through a lymph node biopsy. She presented with elevated ESR, IL-6, and IFN-γ. Viral markers showed elevated IgG and IgM of cytomegalovirus (CMV) and elevated IgG of Epstein-Barr virus (EBV), while changes occurred in the CD4+ T and CD8+ T cell counts. Eventually, the patient achieved disease relief through steroid treatment. Based on these findings, we conducted a comprehensive review of the involvement of viral infection-induced inflammatory response processes and autoimmunity in the pathogenesis of Kikuchi-Fujimoto disease.

Histopathological risk factors for malignancy in dermatomyositis

AIMS

To identify possible histopathological risk factors for malignancy in skin biopsies of dermatomyositis patients.

METHODS AND RESULTS

We analysed clinical metadata and studied 30 skin biopsies of 11 patients with and 12 patients without associated malignancy that were treated in one secondary and one tertiary German medical center between 2009 and 2022 and fulfilling the EULAR/ACR classification criteria for dermatomyositis. Specimens were categorized by malignancy status and evaluated based on H&E, PAS, Alcian Blue and anti-CD123 immunohistochemistry stains. After correcting for multiple testing, biopsies of patients with cancer exhibited more severe basement membrane thickening (p<0.05) and pigment incontinence (p<0.05) compared to patients without tumour burden. Patients with numerous subepidermal melanophages had a more than 5-times increased odds ratio to suffer from an internal malignancy (OR 5.3, 95%CI 1.3-54.2, p<0.05). Furthermore, specimens of the malignancy group presented a distinct superficial distribution pattern of CD123+ plasmacytoid dendritic cells (PDCs, p<0.01). Extravascular eosinophils were absent in all cases.

CONCLUSIONS

Severity of basement membrane thickening, extent of pigment incontinence and superficial distribution pattern of CD123+ PDCs could serve as useful histopathological indicators of risk for malignancy in dermatomyositis.