Is human herpesvirus 6 linked to kikuchi-fujimoto disease? The importance of consistent molecular and serologic analysis

Kikuchi-Fujimoto disease: a diagnostic dilemma

Kikuchi-Fujimoto disease is a benign, self-limiting condition characterized by lymphadenopathy and fever. Its diagnosis can be challenging, as the disease must be differentiated from lymphoma and systemic lupus erythematosus. Patients can present with nonspecific cutaneous lesions. Adequate clinical and histopathologic correlation can aid in the timely diagnosis of Kikuchi's disease, thus preventing the use of unnecessary diagnostic procedures and inappropriate treatments.

Causative agents of Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenitis): a meta-analysis

OBJECTIVE

Kikuchi-Fujimoto disease (KFD) is a self-limiting disorder characterized by histiocytic necrotizing lymphadenitis in the cervical lymph nodes of young women. Although an infectious etiology has been postulated, a definitive causative agent has not been identified. The few dozens of published studies are limited by small sample size and poorly structured study designs. The purpose of this study is to evaluate the association of each infectious agent to KFD that has been studied.

METHODS

We performed metaanalysis using major electronic database (MEDLINE (PubMed), Cochrane library, Embase, Web of Science, NML gateway, LILACS, and Google Scholar). Cross-sectional studies on the positivity of each agent in clinicopathologically diagnosed KFD and normal controls by polymerase chain reaction (PCR) or in situ hybridization (ISH) were carefully retrieved. The included infectious agents were herpes simplex virus (HSV) type 1, 2, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus (EBV), human herpes virus (HHV) 6, 7, 8, parvovirus B19, human papilloma virus, hepatitis B virus, human T-lymphotropic virus 1, Brucella, and Bartonella henselae.

RESULTS

After an exclusion process of 2491 studies, five, two, four, two, two, and three studies on EBV-PCR, EBV-ISH, HHV6-PCR, HHV8-PCR, parvovirus B19-PCR and HHV7-PCR, respectively, were suitable for quantitative meta-analysis.

CONCLUSION

The most suspected pathogen, EBV was not associated to KFD than normal controls (odds ratio=0.28, p=0.005), while the HHV8 positivity was more likely to be associated (odds ratio=8.24, p=0.003) although it still needs further verification. None of other viruses was associated to KFD although the results are limited by small sample size. More studies with large sample size and strict sample selection criteria are necessary in future.

Features of Sequential CT and US-guided Biopsy in Recurrent Kikuchi Disease of the Neck: A Case Report

A 26-year-old woman presented with recurrent Kikuchi disease 7 years after her initial episode. Computed tomography (CT) and ultrasonography demonstrated enlarged lymph nodes with extensive necrosis at the same site as the initial episode. Cytologic and histologic examinations were not conclusive. CT performed 1 month later demonstrated a complete resolution of the lymphadenopathy, which confirmed the diagnosis of recurrent Kikuchi disease. Care must be taken to avoid misdiagnosis of recurrent Kikuchi disease as tuberculous lymphadenitis.

[Medical study of 69 cases diagnosed as Kikuchi's disease]

We studied clinical manifestations, laboratory results, treatment, recurrence, and complications in 69 patients diagnosed with Kikuchi's disease by lymph node pathology from January 1, 1998, to December 31, 2007. Subjects were 34 men and 35 women (median age: 28 years, range: 12 to 58 years). Of the 69, 67 were Japanese and 2 were Korean. Major clinical symptoms and signs were fever >37 degrees (71%) and lymphadenopathy (100%). Lymphadenopathy was cervical in 93% and systemic in 3%. Some experienced night sweats and weight loss. The median white blood cell count was 3800 microL (1,700-9,300 microl), and 50.7% of subjects had leukocytopenia (<4,000 microL). The median serum LDH concentration was 245U/L (129-923 U/L). The median ferritin concentration, measured in 26 cases, was 769 ng/mL (4.5-2,580 ng/mL). The median concentration of soluble IL-2 receptor, measured in 27 cases, was 639 U/mL (0.5-4,000 U/ml). Having observed several cases with abnormally high ferritin and soluble IL2 receptor, we note the importance of carefully considering differential diagnosis from Still's disease and malignant lymphoma. Treatment included no medication in 30% of subjects, nonsteroidal anti-inflammatory drugs alone in 37.7%, steroids alone in 7%, and combined nonsteroidal anti-inflammatory drugs and steroids in 22%. Of the 29% administered steroids, we mostly used prednisolone (0.5-1.0 mg/kg), tapering the dose as clinical features improved. Two developed aseptic meningitis and 2 systemic lupus erythematosus. In total, 75% improved in less than 3 months, whereas 6% showed improvement only after at least 6 months of continued treatment. All were cured, but the condition recurred in 8%. Recurrence was not associated initial the disease duration. Recurrence cannot be predicted but can occur. In some cases, we could not distinguish lymphadenitis from malignant lymphoma or tuberculous lymphadenitis based on clinical features or laboratory data. Diagnosis must thus be based on lymph node pathology. We also must consider the possibility of recurrence or attacks of systemic lupus erythematosus.

Questionable role of human herpesviruses in the pathogenesis of Kikuchi disease

CONTEXT

Kikuchi disease is a self-limiting febrile lymphadenopathy characterized by a patchy area of apoptosis. Kikuchi disease is thought to be caused by a virus, but this has not been clearly demonstrated. Human herpesviruses 6 and 7 (HHV-6 and HHV-7) are lymphotropic viruses that can induce apoptosis in infected lymphocytes. Recently, HHV-8 was reported to be a possible etiologic agent of Kikuchi disease.

OBJECTIVE

To investigate the incidence of HHV-6, HHV-7, and HHV-8 infection in patients with Kikuchi disease.

DESIGN

Seventy archival tissue specimens (from 50 Kikuchi disease cases and 20 control cases) were tested for the presence of HHV-6 and HHV-7 using a nested polymerase chain reaction, and for the presence of HHV-8 using single-step polymerase chain reaction. Immunohistochemistry for HHV-8 expression was carried out in those cases in which HHV-8 was detected using polymerase chain reaction.

RESULTS

Of the 50 cases with Kikuchi disease, 21 (42%) were HHV-6 positive and 32 (64%) were HHV-7 positive. Eight (40%) of the 20 control cases were HHV-6 positive and 9 (45%) were HHV-7 positive. Both HHV-6 and HHV-7 were detected in 15 (30%) of the cases with Kikuchi disease and in 3 (15%) of the control cases. Three (6%) of the 50 cases of Kikuchi disease were HHV-8 positive but revealed no positive cells on immunohistochemical analysis for HHV-8. Human herpesvirus 8 was not expressed in any of the control cases.

CONCLUSIONS

There was no association between the presence of HHV-6 or HHV-7 and Kikuchi disease. Because the HHV-8 genome but not protein was detected in a small proportion of the cases of Kikuchi disease, its potential causative role in this disease should be determined by further studies.

Kikuchi-Fujimoto Disease: analysis of 244 cases

Kikuchi-Fujimoto Disease (KFD) was first described in Japan in 1972. The disease frequently mimics tuberculous lymphadenitis, malign lymphoma, and many other benign and malignant conditions. To our knowledge, there is no previous study comparing the clinical and laboratory characteristics of patients from different geographical parts of the world. We searched literature records beginning from 1991 and analyzed epidemiological, clinical, and laboratory data of 244 patients (including cases diagnosed in our institution) reported in 181 publications. Of the 244 cases, 33% were male and 77% were female. Mean age was 25 (1-64) and 70% was younger than 30. Most of the cases were reported from Taiwan (36%), USA (6.6%), and Spain (6.3%). Fever (35%), fatigue (7%) and joint pain (7%) were the most frequent symptoms, while lymphadenomegaly (100%), erythematous rashes (10%), arthritis (5%), hepatosplenomegaly (3%), leucopenia (43%), high erythrocyte sedimentation rate (40%), and anemia (23%) being the most common findings. KFD was associated with SLE (32 cases), non-infectious inflammatory diseases (24 cases), and viral infections (17 cases). SLE was more frequent in cases from Asia than Europe (28 and 9%, respectively). The disease was self-limiting in 156 (64%) and corticosteroid treatment was necessary in 16 (16%) of the cases. The mortality rate was 2.1%. Early diagnosis is crucial as the clinical and laboratory presentation generally imitates situations needing lengthy and costly diagnostic and therapeutic interventions. Additionally, association with SLE needs further investigation.

Adverse antibiotic-induced eruptions associated with epstein barr virus infection and showing Kikuchi-Fujimoto disease-like histology

The antibiotic-induced eruption of infectious mononucleosis is a well-known clinical phenomenon. Latent viral infection with herpesviridae (eg, human herpes virus 6 (HHV-6) and Epstein-Barr virus (EBV)) is suspected to play a role in the drug hypersensitivity syndrome. The cutaneous pathologic findings have not been reported in the former, and are infrequently reported in the latter entity. Herein, we describe the biopsy findings of a cefprozil-induced rash in infectious mononucleosis and a minocycline-associated drug hypersensitivity syndrome. Biopsy of these exanthematous eruptions revealed an acute vacuolar interface superficial and deep perivascular and interstitial lymphocytic dermatitis. CD8(+) lymphocytes predominated and were associated with non-neutrophilic nuclear (karyorrhectic) debris and numerous small CD68(+) and CD123(+) monocytes. These aforementioned features have been described in cutaneous lesions of Kikuchi-Fujimoto disease, an entity whose clinicopathologic findings overlap with both infectious mononucleosis and lupus erythematosus. Serologic evidence of active and chronic active EBV infection was found in both patients, respectively. No evidence of EBV or HHV6 was found in the cutaneous lesions. Plasmacytoid monocytes (CD68(+)/CD123(+) cells), which produce type I interferon, are believed to play a role in viral immunity by protecting other cells from viral infections and promoting survival of antigen-activated T cells. Their presence in these two putative examples of viral-drug immune dysregulation could be a clue to pathogenesis and represent a common cellular component of some adverse cutaneous drug eruptions.

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.

Human herpesvirus 6 (HHV6) infection

Human herpes virus-6 was first reported in 1986 and is the sixth member of the herpes virus family. HHV-6 consists of two closely related variants HHV-6A and HHV-6B. The majority of infections occur in healthy infants with most infections caused by HHV-6B. The virus preferentially infects CD4+T-lymphocytes and the surface marker CD46 acts as a co-receptor. Infection is followed by persistence and latency in different cells and organs including monocytes/macrophages, salivary glands, the brain and the kidneys. In this article we will discuss the clinical manifestations of HHV-6 infection in healthy children and the syndromes associated with HHV-6 reactivation in immunocompromised patients. Evidence of association between HHV-6 infection and different clinical entities such as multiple sclerosis, malignancy, infectious momononucleosis, drug hypersensitivity syndromes and skin eruptions is discussed. Published data on the use and efficacy of antiviral agents in complicated infections and infections in immunocompromised patients is presented.