Vickie Marshall

Activity of Thalidomide in AIDS-Related Kaposi’s Sarcoma

PURPOSE To assess the toxicity and activity of oral thalidomide in Kaposis sarcoma (KS) in a phase II dose-escalation study. PATIENTS AND METHODS Human immunodeficiency virus (HIV)-seropositive patients with biopsy-confirmed KS that progressed over the 2 months before enrollment received an initial dose of 200 mg/d of oral thalidomide in a phase II study. The dose was increased to a maximum of 1,000 mg/d for up to 1 year. Anti-HIV therapy was maintained during the study period. Toxicity, tumor response, immunologic and angiogenic factors, and virologic parameters were assessed. RESULTS Twenty patients aged 29 to 49 years with a median CD4 count of 246 cells/mm(3) (range, 14 to 646 cells/mm(3)) were enrolled. All patients were assessable for toxicity, and 17 for response. Drowsiness in nine and depression in seven patients were the most frequent toxicities observed. Eight (47%; 95% confidence interval [CI], 23% to 72%) of the 17 assessable patients achieved a partial response, and an additional two patients had stable disease. Based on all 20 patients treated, the response rate was 40% (95% CI, 19% to 64%). The median thalidomide dose at the time of response was 500 mg/d (range, 400 to 1,000 mg/d). The median duration of drug treatment was 6.3 months, and the median time to progression was 7.3 months. CONCLUSION Oral thalidomide was tolerated in this population at doses up to 1,000 mg/d for as long as 12 months and was found to induce clinically meaningful anti-KS responses in a sizable subset of the patients. Additional studies of this agent in KS are warranted.

An Interleukin-6-Related Systemic Inflammatory Syndrome in Patients Co-Infected with Kaposi Sarcoma-Associated Herpesvirus and HIV but without Multicentric Castleman Disease

BACKGROUND Kaposi sarcoma-associated herpesvirus (KSHV) is the causal agent for Kaposi sarcoma (KS) and multicentric Castleman disease (MCD) in human immunodeficiency virus (HIV)-infected patients. Patients with KSHV-MCD develop fevers, wasting, hypoalbuminemia, cytopenias, and hyponatremia that are related to overproduction of KSHV-encoded viral interleukin (IL)-6 (vIL-6) and human IL-6 (hIL-6). METHODS We identified 6 HIV-infected patients with KS or serological evidence of KSHV infection who had severe inflammatory MCD-like symptoms but in whom we could not diagnose MCD, and we hypothesized that these symptoms resulted from vIL-6 overproduction. Serum vIL-6 levels were assessed in these 6 patients and compared with levels in 8 control patients with symptomatic KSHV-MCD and 32 control patients with KS. KSHV viral load, serum hIL-6 level, and human IL-10 level were also evaluated. RESULTS Patients with inflammatory MCD-like symptoms but without MCD had elevated vIL-6 levels, comparable with levels in patients with symptomatic KSHV-MCD, and had levels that were significantly greater than those in control patients with KS (P = .003). Elevated hIL-6, IL-10, and KSHV viral loads were also comparable to patients with symptomatic KSHV-MCD and significantly greater than those with KS. CONCLUSIONS A subset of patients with HIV and KSHV co-infection, but without MCD, can develop severe systemic inflammatory symptoms associated with elevated levels of KSHV vIL-6, IL-6, and KSHV viral loads. Excess lytic activation of KSHV, production of the lytic gene product vIL6, and associated immunologic dysregulation may underlie the pathophysiology of these symptoms. This IL-6-related inflammatory syndrome is important to consider in critically ill patients with HIV and KSHV co-infection.

Conservation of Virally Encoded MicroRNAs in Kaposi Sarcoma-Associated Herpesvirus in Primary Effusion Lymphoma Cell Lines and in Patients with Kaposi Sarcoma or Multicentric Castleman Disease

BACKGROUND MicroRNAs are small noncoding RNAs that posttranscriptionally regulate gene expression. Kaposi sarcoma (KS)-associated herpesvirus (KSHV) encodes 12 distinct microRNA genes, all of which are located within the latency-associated region that is highly expressed in all KSHV-associated malignancies. METHODS We amplified, cloned, and sequenced a 2.8-kbp-long region containing a cluster of 10 microRNAs plus a 646-bp fragment of K12/T0.7 containing the remaining 2 microRNAs from 5 primary effusion lymphoma-derived cell lines and from 17 patient samples. The patients included 2 with classic KS, 12 with AIDS-KS (8 from the United States, 1 from Europe, 3 from Africa, and 4 from Central/South America), and 2 with multicentric Castleman disease (MCD). Additionally, we analyzed the K1, open reading frame 75, and K15 genes to determine KSHV subtypes, and we performed a phylogenetic analysis. RESULTS Phylogenetic analysis of the 2.8-kbp microRNA region revealed 2 distinct clusters of sequences: a major (A/C) and a variant (B/Q) cluster. The variant cluster included sequences from 3 patients of African origin and both patients with MCD. Some microRNAs were highly conserved, whereas others had changes that could affect processing and, therefore, biological activity. CONCLUSIONS These data demonstrate that KSHV microRNA genes are under tight selection in vivo and suggest that they contribute to the biological activity and possibly the pathogenesis of KSHV-associated malignancies.

A Pilot Study of Cidofovir in Patients with Kaposi Sarcoma

A clinical trial was conducted to test the activity of cidofovir (CDV), a drug with in vitro activity against Kaposi sarcoma (KS)-associated herpesvirus (KSHV), in KS. Five patients with human immunodeficiency virus-associated KS (4 receiving antiretroviral therapy) and 2 patients with classical KS were administered CDV (5 mg/kg/dose) weekly for 2 weeks and then every other week. All 7 patients had progression of their KS at a median of 8.1 weeks (range, 5-27 weeks). Skin biopsy specimens of KS lesions showed no change in expression of latent or early lytic genes, but, in the 1 assessable patient, there was decreased expression of a late lytic gene. There was no decrease in the virus load of KSHV in peripheral blood mononuclear cells. This study does not provide proof of principle for the treatment of KS with CDV. However, it remains possible that antiherpesvirus therapy can be developed for herpes-induced tumors.

Prevalence of Kaposi's sarcoma-associated herpesvirus infection in sex workers and women from the general population in Spain.

Transmission routes of Kaposis sarcoma‐associated herpesvirus (KSHV) in the general population are poorly understood. Whereas sexual transmission appears to be common in homosexual men, the evidence for heterosexual transmission is less convincing. In our study, prevalence of KSHV infection was examined among women in the Spanish general population and among sex workers. Subjects consisted of 100 prostitutes and 100 women randomly sampled from the general population and age‐matched to the prostitutes. Women had a personal interview and gynecologic examinations in which a blood sample, cervical cells and oral cells were obtained. Peripheral blood mononuclear cells (PBMC), oral and cervical samples were tested for KSHV DNA by quantitative real‐time PCR. Sera were tested for antibodies against human immunodeficiency virus (HIV) by ELISA and against KSHV by latent IFA and K8.1 ELISA. Women who were positive in either serologic assay or PCR were considered infected by KSHV. Human papillomavirus (HPV) DNA in cervical scrapes were evaluated using the Hybrid Capture System™. The study population had an average age of 30 years and were HIV‐negative. Women from the general population were largely of Spanish nationality, and 61% reported lifetime monogamy. The majority of the prostitutes (76%) were immigrants, primarily from South America. Sex workers were twice as likely to be infected with KSHV than women in the general population (16% vs. 8%, prevalence odds ratio [OR] = 2.2). KSHV was more prevalent among HPV DNA‐positive women (OR = 2.5) and among women with an early age at first sexual intercourse (OR = 2.7, p < 0.05). KSHV DNA was detected by PCR in 3% of the oral cavity samples, in 2% of the cervical samples of the prostitutes and in 1% of the cervical samples of women in the general population. All PBMC samples were negative. These results suggest that in low‐risk countries for KSHV, oral shedding and heterosexual contacts are potential pathways for KSHV transmission.

High-dose zidovudine plus valganciclovir for Kaposi sarcoma herpesvirus-associated multicentric Castleman disease: a pilot study of virus-activated cytotoxic therapy

Kaposi sarcoma herpesvirus (KSHV)-associated multicentric Castleman disease (MCD) is a lymphoproliferative disorder most commonly observed in HIV-infected patients. It is characterized by KSHV-infected plasmablasts that frequently express lytic genes. Patients manifest inflammatory symptoms attributed to overproduction of KSHV viral IL-6, human IL-6, and human IL-6. There is no standard therapy and no established response criteria. We investigated an approach targeting 2 KSHV lytic genes, ORF36 and ORF21, the protein of which, respectively, phosphorylate ganciclovir and zidovudine to toxic moieties. In a pilot study, 14 HIV-infected patients with symptomatic KSHV-MCD received high-dose zidovudine (600 mg orally every 6 hours) and the oral prodrug, valganciclovir (900 mg orally every 12 hours). Responses were evaluated using new response criteria. A total of 86% of patients attained major clinical responses and 50% attained major biochemical responses. Median progression-free survival was 6 months. With 43 months of median follow-up, overall survival was 86% at 12 months and beyond. At the time of best response, the patients showed significant improvements in C-reactive protein, albumin, platelets, human IL-6, IL-10, and KSHV viral load. The most common toxicities were hematologic. These observations provide evidence that therapy designed to target cells with lytic KSHV replication has activity in KSHV-MCD. This trial was registered at www.clinicaltrials.gov as #NCT00099073.

Detection of Kaposi Sarcoma—Associated Herpesvirus DNA in Saliva and Buffy-Coat Samples from Children with Sickle Cell Disease in Uganda

Among 233 children, Kaposi sarcoma-associated herpesvirus (KSHV) DNA was detected in 43% of children seropositive for both K8.1 and orf73, in 29% of children seropositive for K8.1 only, in 14% of children seropositive for orf73 only, and in 7% of children seronegative for both K8.1 and orf73; among 228 mothers, KSHV DNA was detected in 27%, 25%, 4%, and 1%, respectively. KSHV DNA was detected more frequently and at higher levels in saliva than in buffy-coat samples and in children than in mothers. In both children and mothers, detection in saliva was associated with detection in peripheral blood. Detection was associated with K8.1 seropositivity, younger age, and high household density, indicating the importance of in-household person-to-person transmission, likely via saliva.

Human and viral interleukin-6 and other cytokines in Kaposi sarcoma herpesvirus-associated multicentric Castleman disease.

Kaposi sarcoma herpesvirus (KSHV)-associated multicentric Castleman disease (MCD) is a polyclonal B-cell lymphoproliferative disorder. Human (h) IL-6 and a KSHV-encoded homolog, viral IL-6, have been hypothesized to contribute to its pathogenesis, but their relative contributions to disease activity is not well understood. We prospectively characterized KSHV viral load (VL), viral (v) and hIL-6, and other cytokines during KSHV-MCD flare and remission in 21 patients with 34 flares and 20 remissions. KSHV-VL, vIL-6, hIL-6, IL-10, and to a lesser extent TNF-α, and IL-1β were each elevated during initial flares compared with remission. Flares fell into 3 distinct IL-6 profiles: those associated with elevations of vIL6-only (2 flares, 6%), hIL-6 elevations only (17 flares, 50%), and elevations in both hIL-6 and vIL-6 (13 flares, 38%). Compared with hIL-6-only flares, flares with elevated hIL-6 plus vIL-6 exhibited higher C-reactive protein (CRP) (P = .0009); worse hyponatremia (P = .02); higher KSHV VL (P = .016), and higher IL-10 (P = .012). This analysis shows vIL-6 and hIL-6 can independently or together lead to KSHV-MCD flares, and suggests that vIL-6 and hIL-6 may jointly contribute to disease severity. These findings have implications for the development of novel KSHV-MCD therapies targeting IL-6 and its downstream signaling. This trial was registered at clinicaltrials.gov as #NCT099073.

Reactivation of Kaposi’s sarcoma-associated herpesvirus by natural products from Kaposi’s sarcoma endemic regions

Kaposis sarcoma (KS) and its causative agent, Kaposis sarcoma associated herpesvirus (KSHV/HHV‐8), a gamma2 herpesvirus, have distinctive geographical distributions that are largely unexplained. We propose the “oncoweed” hypothesis to explain these differences, namely that environmental cofactors present in KS endemic regions cause frequent reactivation of KSHV in infected subjects, leading to increased viral shedding and transmission leading to increased prevalence of KSHV infection as well as high viral load levels and antibody titers. Reactivation also plays a role in the pathogenesis of KSHV‐associated malignancies. To test this hypothesis, we employed an in vitro KSHV reactivation assay that measured increases in KSHV viral load in KSHV infected primary effusion lymphoma (PEL) cells and screened aqueous natural product extracts from KS endemic regions. Of 4,842 extracts from 38 countries, 184 (5%) caused KSHV reactivation. Extracts that caused reactivation came from a wide variety of plant families, and extracts from Africa, where KSHV is highly prevalent, caused the greatest level of reactivation. Time course experiments were performed using 28 extracts that caused the highest levels of reactivation. The specificity of the effects on viral replication was examined using transcriptional profiling of all viral mRNAs. The array data indicated that the natural extracts caused an ordered cascade of lytic replication similar to that seen after induction with synthetic activators. These in vitro data provide support for the “oncoweed” hypothesis by demonstrating basic biological plausibility.

Molecular Evidence for Mother-to-Child Transmission of Kaposi Sarcoma–Associated Herpesvirus in Uganda and K1 Gene Evolution within the Host

BACKGROUND Epidemiological studies of Kaposi sarcoma (KS)-related herpesvirus (KSHV) indicate that having a KSHV-seropositive mother is a risk factor for KSHV infection in children. METHODS We determined the KSHV K1 sequences in concordantly polymerase chain reaction-positive Ugandan mother-child pairs, to ascertain whether they shared the same viral strain. We also examined sequences amplified from saliva and buffy coat samples from the same subjects, to investigate potential intrasubject sequence differences. RESULTS We obtained K1 sequences from 6 of 10 mother-child pairs. In 1 pair, the subtypes differed between mother and child. The mother and child in 2 other pairs shared the same subtype, but the sequences differed. The mother and child in 2 pairs shared KSHV strains with exact (100%) nucleotide homology. The last pair showed evidence of viral strain concordance between mother and child but also showed evidence of evolution of the viral sequence within the child. Of 26 study subjects, 19 showed no evidence of intrasubject K1 sequence variability, but, in 7 subjects, all of whom were children, amino acid variation of 1%-4% was observed. CONCLUSIONS Our findings are consistent with KSHV transmission from maternal and nonmaternal sources in KS-endemic regions. Our results also provide evidence for ongoing evolution of the K1 gene in KSHV-infected children.