Human herpesvirus 8 and Kaposi sarcoma: how should we screen and manage the transplant recipient?

Prevention of Oncogenic Gammaherpesvirinae (EBV and HHV8) Associated Disease in Solid Organ Transplant Recipients

Long-term risk for malignancy is higher among solid organ transplant (SOT) recipients compared to the general population. Four non-hepatitis viruses have been recognized as oncogenic in SOT recipients-EBV, cause of EBV-associated lymphoproliferative diseases; human herpes virus 8 (HHV8), cause of Kaposi sarcoma, primary effusion lymphoma and multicentric Castleman disease; human papilloma virus, cause of squamous cell skin cancers, and Merkel cell polyomavirus, cause of Merkel cell carcinoma. Two of these viruses (EBV and HHV8) belong to the human herpes virus family. In this review, we will discuss key aspects regarding the clinical presentation, diagnosis, treatment, and prevention of diseases in SOT recipients associated with the two herpesviruses.

Tumors after kidney transplantation: a population study

One of the main causes of post-transplant-associated morbidity and mortality is cancer. The aims of the project were to study the neoplastic risk within the kidney transplant population and identify the determinants of this risk. A cohort of 462 renal transplant patients from 2010 to 2020 was considered. The expected incidence rates of post-transplant cancer development in the referenced population, the standardized incidence ratios (SIR) taking the Italian population as a comparison, and the absolute risk and the attributable fraction were extrapolated from these cohorts of patients. Kidney transplant recipients had an overall cancer risk of approximately three times that of the local population (SIR 2.8). A significantly increased number of cases were observed for Kaposi's sarcoma (KS) (SIR 195) and hematological cancers (SIR 6.8). In the first 3 years post-transplant, the risk to develop either KS or hematological cancers was four times higher than in the following years; in all cases of KS, the diagnosis was within 2 years from the transplant. Post-transplant immunosuppression represents the cause of 99% of cases of KS and 85% of cases of lymphomas, while only 39% is represented by solid tumors. Data related to the incidence, the percentages attributable to post-transplant immunosuppression, and the time of onset of neoplasms, particularly for KS and hematological tumors could help improve the management for the follow-up in these patients.

Kaposi sarcoma in three pediatric liver transplantation recipients

BACKGROUND

Kaposi sarcoma (KS) is an endothelial cell tumor, rare in children. It is 200 times more frequent after solid organ transplantation than in the general population.

METHODS

We report three cases of pediatric patients who developed KS after liver transplantation (LT).

RESULTS

Case 1, a 4-year-old boy undergoing LT due to familial intrahepatic cholestasis. Five months after LT, he presented with fever, dyspnea, and cough with enlarged lymph nodes and splenomegaly, anemia, thrombocytopenia, elevated liver enzymes, and positive EBV viral load. Lymph node biopsy diagnosed KS with an elevated HHV8 viral load. Case 2, a 4-year-old boy who underwent LT due to secondary biliary cirrhosis resulting from extrahepatic biliary atresia. Two years later, graft dysfunction was noticed with positive EBV viral load, thrombocytopenia, massive cervical lymph node enlargement, and splenomegaly. Lymph node biopsy diagnosed KS, Castleman's disease, and plasmablastic lymphoma related to HHV8 infection. Case 3, a 15-month-old girl, who received two LT due to biliary cirrhosis. Six months later, she presented with diarrhea, abdominal distension, anemia, thrombocytopenia, enlarged lymph nodes, splenomegaly, and positive CMV viral load. Axillary lymph node biopsy diagnosed KS and HHV8 infection was confirmed. In all three cases, tacrolimus was discontinued and, after diagnosis, sirolimus was started. All recovered without relapse and have a good graft function.

CONCLUSIONS

Kaposi sarcoma is a rare disease post-LT in children. Recognizing keywords and early diagnosis is crucial for timely treatment and survival.