Presence of human herpesvirus 8 DNA sequences in renal transplantation-associated pleural Kaposi sarcoma

[Primary effusion lymphoma in two kidney transplant recipients]

BACKGROUND

Primary effusion lymphoma (PEL) is a highly malignant non-Hodgkin lymphoma associated with Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8 infection (KSHV/HHV-8). It is chiefly seen in HIV patients and is rare in transplant recipients, possibly going unrecognized.

OBSERVATION

We describe two male kidney transplant recipients, aged 47 and 51 years, followed for Kaposi's sarcoma in skin, lymph nodes, gastrointestinal (GI) tract and lung whose disease was poorly controlled by sirolimus and chemotherapy. Recurrent pleural effusion contrasted with reduction of cutaneous Kaposi lesions. KHSV viral loads were negative or very low in plasma, were negative or very low, whereas those in pleural effusion were high. Lymphoma cells were discovered only seven to nine months after the initial effusion despite repeated needle biopsies. In one patient, tumour cells were co-infected with Epstein-Barr virus.

CONCLUSION

The contrast between a very low KHSV viral load in plasma and a very high viral load pleural effusion should alert physicians and prompt suspicion of PEL in Kaposi's sarcoma patients with recurrent serous effusion. The potential inhibitory role of sirolimus on PEL progression is discussed.

Inflammatory myofibroblastic tumor of epididymis: a case report and review of literature

BACKGROUND

Epididymal inflammatory myofibroblastic tumor, also known by various other synonyms is a rare benign disease. Only eight cases have been reported to date. The most common presentation is a scrotal mass of variable duration. For a scrotal mass it is difficult to distinguish a benign or malignant etiology, in addition to the origin whether from testis or epididymis. As a result the definitive diagnosis can only be established by surgical exploration.

CASE PRESENTATION

We report the ninth case of epididymal IMT who based on clinical and radiological findings underwent radical orchidectomy, with the histology suggestive of inflammatory myofibroblastic tumor. At 4 years follow up the patient is free of disease recurrence.

CONCLUSION

IMT though rare should be considered in the differential diagnosis of epididymal mass. Clinically it is often difficult to distinguish the origin of mass and even though the disease has benign nature and course it is crucial to counsel patients for orchidectomy as definitive diagnosis is established on surgical exploration.

Human herpesvirus-8 infection and Kaposi's sarcoma after liver and kidney transplantation in different geographical areas of Spain

Since data on human herpesvirus 8 (HHV-8) infection in Spain is not available, our purpose was to determine the prevalence of HHV-8 infection and the risk of developing Kaposi's sarcoma (KS) among organ transplant recipients in different geographical areas of Spain. The study population consisted of 1019 liver and kidney transplant recipients recruited in four transplant units in Spain. Only post-transplant serum samples were available for all participants. IgG anti-HHV-8 latent and lytic antigens were detected by using an indirect immunofluorescence assay as well as enzyme-linked immunosorbant assays. In available samples, HHV-8 DNA genome was detected by using a nested polymerase chain reaction in sera, blood mononuclear cells and KS tissues. The prevalence of HHV-8 infection after transplantation was calculated. To determine risk factors for infection, odds ratios (OR) and 95% confidence intervals (CI) were also calculated. Of the 788 kidney transplants, 5 (0.6%) were HHV-8-positive shortly after transplantation. Of the 231 liver transplant individuals, 8 (3.4%) developed IgG anti-HHV-8 antibodies after transplantation. Thus, incidence of HHV-8 infection is significantly higher among liver transplant recipients in comparison with that in the control population (OR=6, 95% CI=1.2-28.5, p<0.05). In this series, HHV-8 prevalence in liver transplant recipients was higher in the northern (6.6-6.9%) than in the central (2.9%) or the southeastern (1.4%) areas of Spain. Four renal transplant recipients (0.5%) and five of the liver transplant recipients (2.16%) developed KS after transplantation. Time of KS diagnosis after transplant is significantly higher in kidney transplant patients (33.7 months) than in liver transplant recipients (10.4 months), indicating that the latter have a higher risk of developing KS.

Immunohistochemical and molecular assessment of human herpesvirus type 8 in gastrointestinal tumours

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract, histologically identified as highly cellular spindle or epithelioid cell tumours, and often positive for CD34 (60-70%). Kaposi's sarcomas (KSs) are similar to GISTs: they are most often found in the gastrointestinal tract (although cutaneous lesions do occur), they are also composed of spindle or epithelioid cells (although erythrocytes are also seen), and the tumour cells are nearly all positive for CD34. Human herpesvirus type 8 (HHV-8) DNA has been found consistently in all types of KS, in particular in CD34 positive KS tumour cells. However, the association between HHV-8 and GIST has not been investigated.

AIMS

To assess the presence of HHV-8 in GISTs.

METHODS

Paraffin wax embedded tissues of 86 primary GISTs and their recurrent or metastatic tumours were analysed immunohistochemically for the CD34 antigen and HHV-8 latent nuclear antigen 1 (LNA-1) and by means of the nested polymerase chain reaction (PCR) and real time PCR for HHV-8 DNA.

RESULTS

None of the 86 GISTs contained HHV-8 DNA sequences or LNA-1 positive cells.

CONCLUSIONS

These results demonstrate the lack of HHV-8 infection in GIST tumour cells. HHV-8 does not appear to play a role in the pathogenesis of GIST, irrespective of the status of the tumour.

Clinicopathological Aspects of 18 Kaposi's Sarcoma among 1055 Greek Renal Transplant Recipients

The incidence of Kaposi's sarcoma (KS) in transplant recipients is 400-500 times greater than that in the general population, and is rising within the transplant population. In this study, between March 1983 and December 2001, 1055 cases were recorded where KS developed in 18 patients (1.7%) who were treated with AZA + CsA + MP, MMF + CsA + MP, MMF + Tac + MP, CsA + MP, or AZA + MP therapy (AZA, azathioprine; CsA, cyclosporine A; MP, methylprednisolone; MMF, mycophenolate mofetil; Tac, Tacrolimus). In the present study, 18 renal transplant recipients who developed KS and were followed and analyzed. Analysis revealed that a continuous state of immunodeficiency is important for the development of KS. Prognosis in patients with KS limited to the skin is favorable, while visceral involvement is associated with high mortality. Transplant function is well preserved in most of the cases. The association, previously described, between human herpesvirus 8 (HHV8) and transplant-associated KS also exists in the studied population.

Human herpesvirus-8 genes are expressed in pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor)

The presence of human herpesvirus-8 DNA sequences, as well as an overexpression of human interleukin-6 and human cyclin D1 in myofibroblastic cells of inflammatory myofibroblastic tumor (inflammatory pseudotumor), has recently been reported. We describe the pattern of human herpesvirus-8 gene expression in five cases of pulmonary inflammatory myofibroblastic tumor. Reverse transcriptase-polymerase chain reaction (RT-PCR), with several positive and negative controls, was performed to detect mRNA of 11 open reading frames encoded by human herpesvirus-8 in lytic and latent stages of viral replicative cycle. We found molecular transcripts from ORF16, ORFK13, and ORF72 in the five cases and from ORFK2 in four of five neoplasms. The corresponding encoded proteins were human homologous oncoproteins (viral cyclin-D), inflammatory cytokines (viral IL-6), and inhibitors of apoptotic pathways (viral FLIP and viral Bcl-2), mostly expressed in a latent viral replicative stage. The rest of open reading frames examined included mainly lytic-associated genes and showed no expression. The spectrum of expressed viral genes is not the same as can be observed in Kaposi's sarcoma or multicentric Castleman's disease, suggesting that human herpesvirus-8 plays a different role in the pathogenesis of its associated diseases. These differences may be related to either cell-specific or immunologic host factors.

Presence of human herpesvirus-8 DNA sequences and overexpression of human IL-6 and cyclin D1 in inflammatory myofibroblastic tumor (inflammatory pseudotumor)

Inflammatory myofibroblastic tumor (IMT) is composed of myofibroblasts, plasma cells, and lymphocytes. Cytokines are possibly involved in its pathogenesis. Human herpesvirus-8 (HHV-8) encodes cell cycle regulatory and signaling proteins. A combination of nested PCR with several negative controls and Southern blot methods showed the presence of HHV-8 DNA in seven cases of IMT. Additionally, strong expression was demonstrated by in situ hybridization in many tumoral nuclei. Most of the myofibroblasts in all of the cases were immunoreactive for human IL-6 and cyclin D1. These cytokines probably have a paracrine action and may sustain myofibroblastic growth. HHV-8 could play an essential role in triggering IMT development by a local reactivation of viral lytic replication. The relationship between HHV-8 and immunosuppression status as the only associated cause for tumorigenesis should be revised.