Classic Kaposi's sarcoma: T-lymphocyte subsets, T4/T8 ratio, and NK cell activity

Immunophenotypic analysis in participants with Kaposi sarcoma following pomalidomide administration

OBJECTIVE

The aim of this study was to evaluate baseline differences by HIV status and the impact of pomalidomide on lymphocyte counts and T-cell subsets in patients with Kaposi sarcoma.

DESIGN

We prospectively evaluated CD4 + and CD8 + T-cell phenotypes in 19 participants with Kaposi sarcoma enrolled on a phase 1/2 study of pomalidomide (NCT01495598), seven without HIV and 12 with HIV on antiretroviral therapy.

METHODS

Trial participants received pomalidomide 5 mg orally for 21 days of 28-day cycles for up to 1 year. Flow cytometry was performed on peripheral blood mononuclear cells at baseline, after three cycles, and at end-of-treatment. Lymphocyte count and T-cell subset comparisons were evaluated by Wilcoxon signed-rank and Mann--Whitney tests.

RESULTS

At baseline, HIV + participants had lower CD4 + cell counts (median 416 vs. 742 CD4 + T cells/μl, P  = 0.006), and a decreased proportion of CD57 + (senescent) CD8 + T cells ( P  = 0.007) compared with HIV - participants. After three cycles, pomalidomide led to an increased proportion of CD45RO + CD27 + (central memory) CD4 + ( P  = 0.002) and CD8 + ( P  = 0.002) T cells, a decrease in CD45RO - CD27 - (effector) CD4 + cells ( P  = 0.0002), and expansion of CD38 + /HLADR + (activated) CD4 + ( P  = 0.002) and CD8 + ( P  ≤ 0.0001) T cells. Increased numbers of activated CD8 + T cells persisted at end-of-treatment ( P  = 0.002). After three cycles and at end-of-treatment, there was reduction in the proportion of CD57 + (senescent) CD4 + ( P  = 0.001, 0.0006), and CD8 + ( P  =  < 0.0001, 0.0004) T cells.

CONCLUSION

Administration of pomalidomide decreased T-cell senescence and increased T-cell activation in patients with Kaposi sarcoma, suggesting pomalidomide activity in Kaposi sarcoma stems in part from its immunomodulatory effects.

[Metastatic bladder metachrone to a kaposi sarcoma cancer at a therapeutic impasse: about a case]

La chimiothérapie est le traitement indiqué pour un carcinome urothélial métastatique de la vessie, la coexistence d'une tumeur de vessie métastatique avec un sarcome de Kaposi pose un sérieux problème d'aggraver le nouveau néoplasie, un cas rare où n'avons pu que confier le patient à sa famille.

Seroreactivity to Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) latent nuclear antigen in AIDS-associated Kaposi's sarcoma patients depends on CD4+ T-cell count

In AIDS/Kaposi's sarcoma (KS) patients, the sensitivity of immunofluorescence assays for detecting antibodies against latent nuclear antigen ranges from 52% to 93%. However, in classic and African KS, sensitivities above 90% have been reported systematically. This study evaluates whether CD4+ T-cell count affects seroreactivity to KSHV LANA and to lytic antigens in AIDS/KS patients. Kaposi's sarcoma-associated herpesvirus (KSHV) latent (IFA-LANA) and lytic (IFA-Lytic and ORF65/K8.1 EIA) antibodies were screened in 184 consecutive samples taken from 36 AIDS/KS patients grouped according to their CD4+ counts as follows: <100 (group A), 100-300 (group B), and >300 (group C) cells/mm(3). At enrollment, the immunofluorescence assay for the detection of antibodies against latent nuclear antigen (IFA-LANA) was positive in 3/11(27.2%) group A patients, in 10/11 (90.9%) group B patients, and in 14/14 (100%) group C patients (P < 0.01). Seropositivity to lytic antigens did not differ according to CD4+ T-cell count. Considering IFA-Lytic and ORF65/K8.1 EIA, seropositivity for lytic antigens was 100% in all three patient groups. In patients whose CD4+ count improved during follow-up, IFA-LANA seroconversion occurred; unstable counts resulted in a decrease in LANA antibody titers while the persistence of high counts resulted in unchanged, elevated antibody titers. In conclusion, LANA seroreactivity in AIDS/KS patients, as assessed by an immunofluorescence assay, depends on CD4+ T-cell count, rendering this evaluation important in the interpretation of seroepidemiological studies of KSHV infection in AIDS patients. To evaluate future serological tests based on latency-associated antigens, the selection of sera from KS patients with CD4+ cell count >300 cells/mm(3) as a positive gold standard is recommended.

Targeting human herpesvirus-8 for treatment of Kaposi??s sarcoma and primary effusion lymphoma

PURPOSE OF REVIEW

Human herpesvirus-8, also called the Kaposi's sarcoma herpesvirus, is present in all cases of Kaposi's sarcoma and primary effusion lymphoma and in some cases of multicentric Castleman's disease. This review discusses mechanisms by which human herpesvirus-8 contributes to tumorigenesis and how this knowledge can be used to target the virus for the treatment of these tumors.

RECENT FINDINGS

Most primary effusion lymphomas and Kaposi's sarcoma tumor cells are latently infected with human herpesvirus-8 and hence resistant to antiherpesvirus drugs that are dependent on lytic replication. In contrast, many of the cells infected with human herpesvirus-8 in multicentric Castleman's disease support lytic replication, so that clinical improvement frequently occurs in response to treatment with antiherpesvirus drugs. The resistance of latently-infected tumor cells to antiherpesvirus drugs can be overcome by inducing human herpesvirus-8 to reenter the lytic cascade in the presence of antiherpesvirus drugs. This leads to apoptosis of virally infected cells without increasing production of infectious virus. Alternatively, the replication and maintenance of the human herpesvirus-8 episome during latency can be disrupted by glycyrrhizic acid or hydroxyurea so that the virus no longer contributes to tumorigenesis. Both the innate and acquired immune systems can also be augmented to help prevent or treat human herpesvirus-8-associated tumors.

SUMMARY

Novel strategies targeting human herpesvirus-8, which is present in all cases of Kaposi's sarcoma and primary effusion lymphoma, provide opportunities for selectively killing tumor cells.

A common genetic variant in FCGR3A-V158F and risk of Kaposi sarcoma herpesvirus infection and classic Kaposi sarcoma

Associations of FCGR3A among men with HIV/acquired immunodeficiency syndrome suggest that host responses affect the pathogenesis of Kaposi sarcoma herpesvirus (KSHV) infection and risk of acquired immunodeficiency syndrome-associated Kaposi sarcoma. Using DNA from two HIV seronegative case-control populations in Italy, we examined whether the functional FCGR3A-V158F variant was associated with risk of KSHV infection or classic Kaposi sarcoma (CKS). In population I, we examined FCGR3A variants and risk of KSHV infection in 34 KSHV latent nuclear antigen (LANA)-seropositive and 120 LANA-seronegative adults from Sardinia (52% male; median age, 45 years; range, 31-60), whereas in population II, we examined risk of CKS from 133 CKS cases and 172 KSHV LANA-seropositive controls from Sicily, Rome, and Naples (70% males; median age, 74 years; range, 29-91). FCGR3A variants were determined by direct sequence analysis of a nested PCR of genomic DNA assay using allele-specific primers. KSHV LANA was determined by immunofluorescence assay. Overall, compared with the 158F allele, 158V was overrepresented among controls from both Mediterranean populations (frequency = 0.52 and 0.51, respectively). After controlling for age, 158V homozygous women were at increased risk of KSHV infection and CKS compared with 158F homozygous women [odds ratio (OR), 8.7; 95% confidence interval (95% CI), 0.8-98 and OR, 3.8; 95% CI, 1.0-14, respectively], whereas homozygous men were at decreased risk (OR, 0.4; 95% CI, 0.1-2.3 and OR, 0.4; 95% CI, 0.2-0.8, respectively). Significant gene-dose effects were observed among men and women at risk for CKS (P(trend) < or = 0.05). Our findings suggest that gender differences could possibly modify the effect of FCGR3A on risk of KSHV infection and CKS. Additional studies are required to confirm these relationships and determine their etiologic significance.

Increased prevalence of renal cell carcinoma in patients with HIV infection

Following the observation of the occurrence of renal cell carcinoma (RCC) in a local HIV patient, a retrospective case review was conducted on our local hospital population to determine if the prevalence of RCC in patients with HIV infection was greater than in the non-HIV population. All 66,715 unique adult patient admissions (over 18) to the Medical Center of Central Georgia from 1990 through 1994 were reviewed to determine the total number of HIV admissions, the total number of patients with RCC, and the total number of patients with concomitant RCC and HIV infection. The expected prevalence of HIV-positive adults with RCC in this hospital population was then calculated based on local RCC prevalence data using the Poisson equation. Three hundred eight admissions were HIV infected, two of which had concomitant RCC. Forty-eight additional cases of RCC were documented during this time in non-HIV patients. The probability of an adult coming to this institution with RCC is 0.0007. Using this density in the Poisson equation, the probability of observing two cases of RCC in 308 HIV admissions was 0.01873, p < 0.05. The difference between the two proportions equation yielded a z value of 1.121. Data reveal that the prevalence of RCC in our hospital HIV patients is 8.5 times greater than in our non-HIV population, with an average age of occurrence approximately 15 years younger than national statistics.

Kaposi's sarcoma in an HIV-negative CLL patient as the cause of thrombocytopenia

A patient is described with a rapidly progressive Kaposi's sarcoma following immunosuppressive therapy with fludarabine monophosphate (FAMP) for chronic lymphocytic leukemia. The development of this tumor was accompanied by progressive thrombocytopenia, due to trapping of the platelets in the Kaposi sarcoma, without signs of consumptive coagulopathy or microangiopathic hemolytic anemia. This sequestration process might be caused by the abnormal structure of the tumoral vessels, leading to exposure of subendothelial structures like collagen, von Willebrand's factor, and tenascin to the vessel lumen. A severe immunosuppression due to the lymphocytotoxic effect of FAMP on several T-cell subpopulations was seen. This case confirms the importance of immunosuppression as a co-factor in the development of Kaposi's sarcoma also in HIV-negative patients, and adds Kaposi's sarcoma to the differential diagnosis of thrombocytopenia in immunosuppressed patients.

In vivo modulation of natural killer cell activity by tamoxifen in patients with bilateral primary breast cancer

Natural killer (NK) cell activity, the autologous mixed lymphocyte reaction (AMLR) and proportions of T cell subpopulations (CD3+/CD4+ and CD3+/CD8+) and NK cells (CD16+) were studied in 21 patients with bilateral primary breast cancer (BBC), 10 patients with single-breast cancer (SBC) and 20 healthy controls. All patients studied had no evidence of disease and had been off radiotherapy and/or chemotherapy for at least 1 year. Ten patients with BBC were also treated with tamoxifen. Patients with SBC had NK cell activity, AMLR responses and T cell subpopulations that were comparable to those of normal controls. In patients with BBC, a significant (P < 0.01) increase in NK activity compared to that in normal controls (42 +/- 13% versus 21 +/- 10%, effector-to-target cell ratio, 25:1) and a significant (P < 0.05) decrease in CD4+ T cell proportions (30 +/- 15% versus 49 +/- 13%) and absolute numbers (472 +/- 82/mm3 versus 953 +/- 131/mm3) were found. However, the proliferative response of BBC patients' T lymphocytes in AMLR was in the range of the normal controls. Lymphocytes derived from 10 BBC patients treated with tamoxifen exhibited NK cell activity that was comparable to that of normal controls and patients with SBC, and was significantly (P < 0.01) reduced compared to the pretreatment period. BBC patients who received tamoxifen also show a reduction in the proportion of CD4+ T cells and in AMLR proliferative responses, which decreased compared to levels in normal controls. Taken together, these results indicate that long-term tamoxifen treatment modulates immune responses in BBC patients.