AIDS-associated malignancies: research perspectives

Heat-shock proteins in infection-mediated inflammation-induced tumorigenesis

Inflammation is a necessary albeit insufficient component of tumorigenesis in some cancers. Infectious agents directly implicated in tumorigenesis have been shown to induce inflammation. This process involves both the innate and adaptive components of the immune system which contribute to tumor angiogenesis, tumor tolerance and metastatic properties of neoplasms. Recently, heat-shock proteins have been identified as mediators of this inflammatory process and thus may provide a link between infection-mediated inflammation and subsequent cancer development. In this review, the role of heat-shock proteins in infection-induced inflammation and carcinogenesis will be discussed.

Epstein-Barr virus-associated B-cell lymphoma in the setting of iatrogenic immune dysregulation presenting initially in the skin

BACKGROUND

Epstein-Barr virus (EBV) has been implicated in B-cell lymphoma associated with iatrogenic immune dysregulation, primarily in the context of extracutaneous lymphoma.

METHODS

We describe six patients, five transplant recipients receiving cyclosporine and one patient with rheumatoid arthritis receiving methotrexate, who developed cutaneous presentations of EBV-associated B-cell lymphoma. Human herpesvirus 8 (HHV8) and EBV thymidine kinase (vTK) expression were also explored.

RESULTS

The cases comprised plasmablastic lymphoma (one case), plasmacytic marginal zone lymphoma (two cases), and diffuse large B-cell lymphoma (three cases). There was a monoclonal gammopathy in one and concurrent extracutaneous disease in two of the six patients. EBV-associated latent small nuclear RNA was detected in all cases with coexpression of HHV8 in one of the five cases and of vTK in three of the six cases. Three patients responded to a reduction in the immunosuppressive regimen and antiviral therapy. Recurrent disease developed in two, with one patient succumbing to multiorgan dissemination.

CONCLUSIONS

EBV-associated cutaneous B-cell lymphoma is characterized by a long interval between the initiation of immunosuppression and the development of lymphoma. Although previous reports have reported an indolent clinical course, an aggressive clinical course may occur. HHV8 and lytic phase EBV antigens are detected in some cases, possibly suggesting a pathogenetic role.

Epstein-Barr virus- and human herpesvirus 8-associated primary cutaneous plasmablastic lymphoma in the setting of renal transplantation

BACKGROUND

Plasmablastic lymphoma (PBL) is a recently recognized entity most often reported in the oral cavity, mainly in the setting of underlying human immunodeficiency viral infection whereby a role for Epstein-Barr virus (EBV) and more recently human herpesvirus 8 (HHV8) has been described. Although EBV has been implicated in a variety of lymphoproliferative lesions, until recently HHV8 has only been associated with primary effusion lymphoma, multicentric Castleman's disease, and Kaposi's sarcoma. We describe a case of PBL occurring in the setting of renal transplantation.

METHODS

We encountered a case of PBL occurring in the setting of renal transplantation. We characterized the tumor by routine immunohistochemistry and evaluated for the presence of immunoglobulin light chain restriction and EBV RNA by in situ hybridization. We assessed for the presence of HHV8 RNA by reverse transcriptase in situ hybridization.

RESULTS

The tumor showed a histomorphology compatible with a PBL. In addition, there was strong RNA expression in the neoplastic cells for EBER-1, EBER-2, and HHV8.

CONCLUSION

This case suggests a possible role of both viruses in the pathogenesis of PBL in sites other than the oral cavity and expands the spectrum of post-transplantation lymphoproliferative disease to include PBL.

An unexpectedly high incidence of Epstein-Barr virus lymphoproliferative disease after CD34+ selected autologous peripheral blood stem cell transplant in neuroblastoma

The risk of Epstein–Barr virus lymphoproliferative disease (EBV-LPD) increases with the use of highly immunosuppressive therapies. Allogeneic BMT, especially supported by T-cell-depleted stem cell products, is a risk factor for EBV-LPD. Although the risk of EBV-LPD after autologous transplantation is low, case reports of this complication in the autologous setting exist. We report a higher incidence than previously described of EBV-LPD in children undergoing sequential high-dose chemotherapy supported with CD34 selected peripheral blood stem cells (CD34+ PBSC). The median time to LPD after tandem transplant was 3 months (range 1–5 months). Five patients out of 156 (3.5%) developed EBV-LPD while enrolled on two trials of tandem autologous SCT in high-risk pediatric malignancies. Both studies employed five cycles of induction therapy, followed by tandem autologous PBSC transplants. In all, 108 out of 156 patients received CD34+ PBSC; 48 received unselected PBSC. All patients contracting LPD were from the CD34 selected group. Treatment of EBV-LPD included rituximab in four out of five patients, IVIg in two out of five patients, and gancyclovir in two out of five patients. EBV-LPD resolved in four out of five patients. We conclude that the combination of tandem SCT and CD34 selection may have increased immunosuppression in these patients to a point where there is an elevated risk of EBV-LPD.

Chemotherapy for human immunodeficiency virus-associated non-Hodgkin's lymphoma in combination with highly active antiretroviral therapy

PURPOSE

This study investigated the efficacy, toxicity, and pharmacokinetic interactions resulting from simultaneous combination chemotherapy and highly active antiretroviral therapy (HAART) for patients with human immunodeficiency virus (HIV)-associated non-Hodgkin's lymphoma (NHL). In addition, the effects on viral load, CD4 counts, and opportunistic infections were examined with the use of combination chemotherapy combined with HAART.

PATIENTS AND METHODS

Sixty-five patients with previously untreated and measurable disease at any stage of HIV-associated NHL of intermediate or high grade were entered onto this study at 17 different centers. The first 40 patients entered onto the study received reduced doses of cyclophosphamide and doxorubicin, combined with vincristine and prednisone (modified CHOP [mCHOP]), whereas the subsequent 25 patients entered onto the study received full doses of CHOP combined with granulocyte colony-stimulating factor (G-CSF). All patients also received stavudine, lamivudine, and indinavir.

RESULTS

The complete response rates were 30% and 48% among patients who received mCHOP and full-dose CHOP combined with HAART, respectively. Grade 3 or 4 neutropenia occurred in 25% of patients receiving mCHOP and 12% of those receiving full-dose CHOP combined with G-CSF (25% v 12%). There were similar numbers of patients with grade 3 or 4 hyperbilirubinemia (12% and 17%), constipation and abdominal pain (18% and 17%), and transaminase elevation (48% and 52%) on the modified and full-dose arms of the study, respectively. Doxorubicin clearance and indinavir concentration curves were similar among patients on this study and historical controls, whereas cyclophosphamide clearance was 1.5-fold reduced as compared with control values. Human immunodeficiency virus (HIV) load declined from a median baseline value of 29,000 copies/mL to a median minimum value on therapy of 500 copies/mL.

CONCLUSION

Either modified-dose or full-dose CHOP chemotherapy for HIV-NHL, delivered with HAART, is effective and tolerable.

Induced minisatellite germline mutations in herring gulls (Larus argentatus) living near steel mills

Despite widespread industrial release of genotoxic contaminants, little is understood of their role in inducing germline mutations in natural populations. We used multilocus DNA fingerprinting to quantify germline minisatellite mutations in families of herring gulls (Larus argentatus) in three nesting categories: (a) near cities with large steel mills operating coking ovens; (b) near cities without steel mills; and (c) in rural locations removed from point sources of contamination. Gulls nesting near integrated steel mills showed significantly higher mutation rates than gulls from rural locations (Fisher's exact, P=0.0004); urban sites without steel mills fell midway between steel and rural sites (difference from rural; Fisher's exact, P=0.19). Distance of the nesting location of herring gulls from the steel industries' coking ovens was negatively correlated with minisatellite mutation rate demonstrating significant risk for induced germline mutations in cities with steel operations (Kendall Tau; tau=0.119; P<0.0001).