Kaposi's Sarcoma Lesions Research Articles

Lymphangiectatic Kaposi's sarcoma in a patient with AIDS

Kaposi's sarcoma is a malignant disease that originates in the lymphatic endothelium. It has a broad spectrum of clinical manifestations. Its four distinct clinical forms are: classic, endemic, iatrogenic and epidemic Kaposi's sarcoma. In non-HIV-associated Kaposi's sarcoma, the disease is typically limited to the lower extremities, but in immunodeficient patients, it is a multifocal systemic disease. The clinical course of the disease differs among patients, ranging from a single or a few indolent lesions to an aggressive diffuse disease. Advanced Kaposi's sarcoma lesions, typically those on the lower extremities, are often associated with lymphedema. In this paper, we report a case of a patient with a rare form of AIDS-associated Kaposi sarcoma called lymphangiectatic Kaposis's sarcoma.

Clinical characteristics and outcomes of HIV‐infected children diagnosed with kaposi sarcoma in malawi and botswana

Kaposi sarcoma (KS) is the most common HIV-associated malignancy in sub-Saharan Africa. The presentation and outcomes of pediatric KS are not well understood. We performed a retrospective cohort analysis of 81 HIV-infected children with KS at the Baylor Children's Clinical Centres of Excellence in Malawi and Botswana from March 2003 to October 2009. Eighty-one children with KS were identified whose median age was 8.0 (inter-quartile range 5.1-11.3) years. KS lesions were presented primarily on the skin (83%), lymph nodes (52%), and oral mucosa (41%). Occasionally disease was limited to the lymph nodes only (10%). Severe immunosuppression (70%), anemia (29%), and thrombocytopenia (17%) were common laboratory findings. Highly active antiretroviral therapy (HAART) was administered to 94% of children, including 77% who received HAART plus chemotherapy. KS immune reconstitution inflammatory syndrome (IRIS) occurred in 22%. Disease status 12 months after KS diagnosis was determined for 69 children: 43% were alive and 57% had died. Severe immunosuppression was independently associated with mortality in multivariate analysis (OR = 4.3; 95% CI 1.3-14.6; P = 0.02). KS occurs in a significant number of HIV infected children in sub-Saharan Africa. Pediatric KS is distinct from KS in adults. Lymph node involvement was a common manifestation of KS in children, and severe immunosuppression was associated with the highest mortality risk. Though overall mortality was high in children with KS, patients did achieve clinical remission in settings with limited diagnostic and therapeutic resources.

Complete response of endemic Kaposi sarcoma lesions with high-dose-rate brachytherapy: Treatment method, results, and toxicity using skin surface applicators

To analyze the clinical outcome of Kaposi sarcoma skin lesions treated with high-dose-rate (HDR) brachytherapy in patients with a minimum of 2 years of followup. Between February 2006 and July 2008, all patients with Kaposi sarcoma who received (192)Ir HDR brachytherapy using a skin surface applicator were evaluated for clinical response. Responses to treatment and toxicity were scored using standard criteria. Sixteen cases were collected. Treatment was delivered in four to six fractions, over a period of approximately 12 days. The specified dose ranged from 24 to 35Gy. Median followup the lesion was 41.4 months. No lesion was greater than 2cm. All patients had a complete response to treatment, with no evidence of local recurrence or tumor progression. Thirteen lesions developed Grade 1 and two lesions had Grade 2 acute skin reactions. One patient developed late skin changes with telangiectasias and hypopigmentation. HDR brachytherapy treatment seems to be an effective noninvasive option for patients with small cutaneous Kaposi sarcoma lesions, delivering excellent cosmesis and local control in our small series. Fewer fractions over a shorter period used in our group offer patients more convenience compared with other common regimens. Although HDR is being used more frequently for many surface applications, additional clinical studies with larger numbers of patients and longer followup are needed to confirm the general impression that it is an excellent option for many patients.

Pulmonary manifestations of human herpesvirus-8 during HIV infection

Human herpesvirus (HHV)-8 is an oncogenic gamma herpesvirus that was first described in 1994 in Kaposi sarcoma lesions. HHV-8 is involved in the pathophysiological features of multicentric Castleman's disease (MCD) and primary effusion lymphoma (PEL), both rare B-cell lymphoproliferative diseases. HHV-8-related tumours occur almost exclusively in immunocompromised patients, mostly those with HIV infection. Combined antiretroviral therapies have reduced the incidence of Kaposi sarcoma but not MCD and PEL. HHV-8-related diseases frequently exhibit pulmonary involvement, which may indicate the disease. Kaposi sarcoma in the lung is often asymptomatic but may require specific therapy. It mostly shows cutaneous or mucosal involvement. Patients with typical MCD present fever and lymphadenopathy associated with interstitial lung disease without opportunistic infection. Specific treatment may be urgent. PEL provokes a febrile, lymphocytic-exudative pleural effusion, without a pleural mass on computed tomography scan. Rapid diagnosis prevents unnecessary examinations and leads to specific, rapid treatment. Therapy is complex, combining antiretroviral therapy and chemotherapy.

Kaposi's Sarcoma-Associated Herpesvirus Latency in Endothelial and B Cells Activates Gamma Interferon-Inducible Protein 16-Mediated Inflammasomes

Kaposi's sarcoma-associated herpesvirus (KSHV) infections of endothelial and B cells are etiologically linked with Kaposi's sarcoma (KS) and primary effusion B-cell lymphoma (PEL), respectively. KS endothelial and PEL B cells carry multiple copies of the nuclear episomal latent KSHV genome and secrete a variety of inflammatory cytokines, including interleukin-1β (IL-1β) and IL-18. The maturation of IL-1β and IL-18 depends upon active caspase-1, which is regulated by a multiprotein inflammasome complex induced by sensing of danger signals. During primary KSHV infection of endothelial cells, acting as a nuclear pattern recognition receptor, gamma interferon-inducible protein 16 (IFI16) colocalized with the KSHV genome in the nuclei and interacted with ASC and procaspase-1 to form a functional inflammasome (Kerur N et al., Cell Host Microbe 9:363-375, 2011). Here, we demonstrate that endothelial telomerase-immortalized human umbilical cells (TIVE) supporting KSHV stable latency (TIVE-LTC cells) and PEL (cavity-based B-cell lymphoma 1 [BCBL-1]) cells show evidence of inflammasome activation, such as the activation of caspase-1 and cleavage of pro-IL-1β and pro-IL-18. Interaction of ASC with IFI16 but not with AIM2 or NOD-like receptor P3 (NLRP3) was detected. The KSHV latency-associated viral FLIP (vFLIP) gene induced the expression of IL-1β, IL-18, and caspase-1 mRNAs in an NF-κB-dependent manner. IFI16 and cleaved IL-1β were detected in the exosomes released from BCBL-1 cells. Exosomal release could be a KSHV-mediated strategy to subvert IL-1β functions. In fluorescent in situ hybridization analyses, IFI16 colocalized with multiple copies of the KSHV genome in BCBL-1 cells. IFI16 colocalization with ASC was also detected in lung PEL sections from patients. Taken together, these findings demonstrated the constant sensing of the latent KSHV genome by IFI16-mediated innate defense and unraveled a potential mechanism of inflammation induction associated with KS and PEL lesions.

Kaposi Sarcoma

Kaposi sarcoma (KS) is a low-grade vascular tumor associated with Kaposi sarcoma herpesvirus/human herpesvirus 8 (KSHV/HHV8) infection. Kaposi sarcoma lesions predominantly present at mucocutaneous sites, but may involve all organs and anatomic locations. Recognized epidemiologic-clinical forms of KS include classic, African (endemic), AIDS-associated (epidemic), and iatrogenic KS. New clinical manifestations have been described, such as antiretroviral therapy-related KS regression or flares. Kaposi sarcoma lesions evolve from early (patch stage) macules into plaques (plaque stage) that grow into larger nodules (tumor stage). Newer histologic variants include anaplastic, hyperkeratotic, lymphangioma-like, bullous, telangiectatic, ecchymotic, keloidal, pyogenic granuloma-like, micronodular, intravascular, glomeruloid and pigmented KS, as well as KS with sarcoidlike granulomas and KS with myoid nodules. Latency-associated nuclear antigen (HHV8) is the most specific immunohistochemical marker available to help distinguish KS from its mimics. Since KS remains one of the most common AIDS-defining malignancies, it is important that pathologists be able to recognize KS and its contemporary manifestations.

Kaposi Sarcoma in a Patient with Chronic Renal Failure Undergoing Dialysis

Kaposi sarcoma (KS) is a multicentric proliferative vascular tumor involving the skin and other organs. Human herpesvirus 8 (HHV-8) has been detected in KS lesions and is considered the putative causative agent of KS. The relationship between chronic renal failure, HHV-8, and KS is not clear. KS appears to develop in association with renal transplantation, but is unlikely with dialysis, and there have been few reports on this. Here, we report the case of a 51-year-old man, who underwent peritoneal dialysis to treat chronic renal failure, and presented with multiple brownish plaques on his soles. On histopathological examination, abnormally proliferated vessels, vascular slits, and spindle-shaped cells were seen in the dermis. Immunohistochemical staining for HHV-8 was positive. This case is another example in which factors other than immunosuppression contributed to the development of KS, due to activation of HHV-8.

Oral kaposi’s sarcoma and the global HHV-8 story

Background Kaposi's sarcoma (KS) remains the major AIDS-defining neoplasm worldwide, although incidence has declined in HIV-populations with widespread antiretroviral treatment. In high-incidence regions, oral lesions are common, accurate and rapid diagnosis being important for patient care. We sought to improve methods for diagnosis and characterisation of virus in patients from Australia and Africa. Methods Histopathology and immunocytochemistry (ICC) for LANA-1 HHV-8 antigen on paraffin sections; HHV-8 ORF73 and ORF26 qPCR on DNA from lesions. Results In Australian patients ( n= 37), KS lesions from various body sites had characteristic histomorphology: all were positive by ICC. HHV-8 involvement was confirmed by rtPCR, and a qPCR assay developed. 1 Sequencing showed most to be Subtype-A with two being Subtype-C. From Kenya, 17 of 19 non-oral, but only 15 of 28 presumed oral-KS, were confirmed by ICC: there were seven pyogenic granulomas, two deep mycoses and four HHV-8 negative inflamed/ulcerated mucosae. All Kenyan samples produced the same HHV-8 Subtype, thought to be because of laboratory contamination. Conclusions ICC for HHV-8 LANA-1 antigen is an essential tool for accurate diagnosis, especially for differential diagnosis of common oral lesions. PCR is best avoided in resource-poor settings unless strict laboratory hygiene can be guaranteed.

Cavernous Hemangioma-Like Kaposi Sarcoma: Histomorphologic Features and Differential Diagnosis

Aim. Cavernous hemangioma-like Kaposi sarcoma is a rare morphologic type of Kaposi sarcoma. So far there are no cases in the literature defining the histological features of this morphologic spectrum in detail. In this study we presented two classical-type cutaneous Kaposi sarcoma cases with histologic findings resembling cavernous hemangioma in company with clinical and histopathological data. Cases. One hundred and eighty-five classical-type cutaneous Kaposi sarcoma lesions in 79 patients were assessed retrospectively in terms of histopathological features. Findings of two cases showing features of cavernous hemangioma-like Kaposi sarcoma whose clinical data could be accessed were presented in accompany with the literature data. Both cases were detected to have bluish-purple, protruded, irregularly bordered cutaneous lesions. Histopathological examination revealed a lesion formed by cavernous hemangioma-like vascular structures organized in a lobular pattern that became dilated and filled with blood. Typical histological findings of early-stage KS, consisting of mononuclear inflammation, extravasated erythrocytes, and a few immature vascular structures in superficial dermis, were observed. All cases were serologically HIV-1 negative. A positive reaction with HHV-8, CD31, CD34, and D2-40 monoclonal antibodies was identified at both cavernous hemangioma-like areas and in immature vascular structures. Results. Cavernous hemangioma-like Kaposi sarcoma is a rare Kaposi sarcoma variant presenting with diagnostic challenges, that may be confused with hemangioma. As characteristic morphological features may not be observed in every case, it is important for diagnostic purposes to show immunohistochemical HHV-8 positivity in this variant.

Upregulation of human β-defensin-3 and cathelicidin LL-37 in Kaposi’s sarcoma

Background: Kaposi’s sarcoma (KS) is a rare neoplasm of lymphatic endothelial cells. Human herpes virus 8 (HHV-8) is considered to be a necessary, but not sufficient causal agent of KS and additional cofactors remain unknown. In this study we evaluated the expression of human β defensin (HBD)-3 and LL-37 in cutaneous lesions of KS in comparison to the healthy skin of normal subjects. Methods: We performed a quantitative immunohistochemical study of HBD-3 and LL-37 on skin lesions from 18 patients having KS, and on healthy skin from 12 normal controls. Results: HBD-3 and LL-37 were significantly upregulated in epidermal and dermal specimens of all KS patients in comparison to normal skin of healthy controls. The immunostaining score of dermal HBD-3 was significantly higher in nodular lesions (9.6 ± 2.4) versus plaque lesions (4.1 ± 2.2), P = 0.001. Also the immunostaining score of dermal LL-37 was significantly higher in nodular lesions versus plaque lesions (P = 0.001). Conclusions: We have demonstrated for the first time that HBD-3 and LL-37 are significantly upregulated in lesional skin of KS in comparison to the skin of healthy controls. The obtained data suggest a possible involvement of these antimicrobial peptides in the pathogenesis of KS. However, the biological significance of HBD-3 and LL-37 in KS lesions needs further research.

Upregulation of human β-defensin-3 and cathelicidin LL-37 in Kaposi’s sarcoma

Background: Kaposi’s sarcoma (KS) is a rare neoplasm of lymphatic endothelial cells. Human herpes virus 8 (HHV-8) is considered to be a necessary, but not sufficient causal agent of KS and additional cofactors remain unknown. In this study we evaluated the expression of human β defensin (HBD)-3 and LL-37 in cutaneous lesions of KS in comparison to the healthy skin of normal subjects. Methods: We performed a quantitative immunohistochemical study of HBD-3 and LL-37 on skin lesions from 18 patients having KS, and on healthy skin from 12 normal controls. Results: HBD-3 and LL-37 were significantly upregulated in epidermal and dermal specimens of all KS patients in comparison to normal skin of healthy controls. The immunostaining score of dermal HBD-3 was significantly higher in nodular lesions (9.6 ± 2.4) versus plaque lesions (4.1 ± 2.2), P = 0.001. Also the immunostaining score of dermal LL-37 was significantly higher in nodular lesions versus plaque lesions (P = 0.001). Conclusions: We have demonstrated for the first time that HBD-3 and LL-37 are significantly upregulated in lesional skin of KS in comparison to the skin of healthy controls. The obtained data suggest a possible involvement of these antimicrobial peptides in the pathogenesis of KS. However, the biological significance of HBD-3 and LL-37 in KS lesions needs further research.

Malignancies Following Liver (LT) and Kidney Transplantation (KT) in the HIV-Infected Recipient

Chronic exposure to HIV and co-pathogens as well as prolonged antiretroviral therapy has resulted in increased morbidity and mortality rates from end-stage liver and kidney disease in the HIV infected population. We performed a prospective, nonrandomized multicenter trial (NIH AI052748) to determine the safety and efficacy of KT and LT in people with HIV. This analysis examines incidence and outcomes of post-transplant (tx) malignancies in this group. Methods: Participants required CD4 count of at least 200/μL (KT) and 100/μL (LT) and undetectable plasma HIV-1 RNA levels on a stable antiretroviral regimen. Post-tx malignancies were identified via query of adverse events. A subset of 89 subjects was also followed via anal cytology for HPV-associated neoplasia. Results: 275 HIV infected subjects (150 KT, 125 LT) underwent transplantation. Median [IQR] CD4 count at transplant was 471 [274-663] in KT and 179 [74-320] in LT. Median age at KT and LT were 46 and 48 years. 69% KT were black and 69% LT were white. Hepatocellular cancer (HCC) within Milan criteria was present in 45 (36%) pre-LT. 3-year survival (95% CI) for KT and LT was 91% (84%-95%) and 67% (56%-75%) at median follow-up of 2.3 and 2.7 years, respectively. In KT, 13 out of 150 patients (8.7%) developed 14 post-tx malignancies: 5 skin cancers (CA), 3 de novo cutaneous Kaposi sarcoma (KS) lesions, 1 penis squamous CA, 3 head and neck CA, and 2 renal cell CA. KS did not recur in any of the 3 patients with pre-tx KS. There were 3 CA related deaths in KT; 2 secondary to metastatic renal cell CA and 1 to metastatic oral squamous cell CA. In LT, 12 patients (10%) developed 14 post-tx malignancies: 9 skin cancers, 2 recurrent HCC, 1 cholangioCA,, 1 de novo KS and 1 lymphoma. There were 4 CA related deaths in this group due to 2 recurrent HCC, 1 recurrent cholangioCA, and 1 lymphoma. In patients monitored for HPV-associated neoplasia, there was increased risk of high-grade (HSIL) after tx. Conclusions: Despite the necessity for chronic immunosuppression, de novo malignancy post-tx in the HIV positive patient is infrequent and is similar to that seen in the non-HIV population. In particular, recurrent HCC after LT is rare, de novo KS is uncommon and was easily treated with sirolimus, and there were no cases of EBV-related lymphoproliferative disorder. HPV mediated disease may be problematic in people infected with HIV undergoing transplant, and will require longer term rigorous follow-up.

Disseminated bone lesions in AIDS‐associated Kaposi sarcoma, a bad prognosis? About four cases

Kaposi sarcoma (KS) can present with a wide range of clinical features ranging from minimal cutaneous disease to a rapidly progressing neoplasm. Bone lesions are most often discovered accidently in the context of radiological investigations done for the screening of KS‐visceral involvement [1]. Little is known on clinical outcome and response to antiretroviral therapy (ART) and/or chemotherapy of these lytic osseous lesions. We report four cases with bone involvement in the context of systemic KS and aim at describing the long‐term clinical outcome in two of these patients. Cases of AIDS‐associated KS with disseminated bone lesions were collected in the HIV Unit, University Hospital Geneva, Switzerland. Patients were compared on clinical, biological and radiological features and therapeutic responses. Between 2002 and 2012, four HIV1‐infected patients with T1 stage of KS presented disseminated osseous lesions (Table 1). Mean age was 43 years (range 39 ‐ 47 years), mean time of follow up until our analysis was 48.5 months (SD 53.8), and mean CD4 count at KS diagnosis was 190.5 c/mL (SD 202.8). All patients showed hypodense bone lesions predominating the axial skeleton (figure 1), but no radiological imaging was performed to search for peripheral bone lesions.No patient reported pain or experienced pathological fractures. In one patient a dual‐energy X‐ray absorptiometry (DXA) showed a bone mineral density within normal range after 10 years of KS diagnosis with disseminated bone lesions. No radiological change was observed in that patient despite stable KS disease after 13 cycles of liposomal doxorubicin and ART (figure 1). We describe a well‐documented long‐term follow up of disseminated osseous AIDS‐associated KS disease. In our four cases, lytic bone lesions were asymptomatic and were not associated with bone fragility. We even could confirm the KS nature of the lesions by bone biopsy in patient B (3 months after KS diagnosis), as the differential diagnosis is wide, and include bacillary angiomatosis, cancers or metastasis. Chemotherapy and antiretroviral treatment did not affect bone lesions using CT scan despite a good response on other KS‐affected sites. Prognostic factors are well established in AIDS‐associated KS [2]; however disseminated bone disease does not seem to have an impact on disease evolution. A larger sample size is needed to confirm this hypothesis.Patient with 10yr follow up, lumbar vertebre after 6 (2002) and 13 (2012) sycles of chemotherapy with Liposomal Doxorubicin.image Baseline characteristics for all four patients with AIDS‐related KS and osseous lesions. Staging classification is based on Known SE et al. J Clin Oncol 1989; 7: 1201–7 and includes the following parameters: T for Tumor (T0 = KS confined to skin and minimal oral disease, T1 = all other manifestations), I for Immune system (I0 = CD4 cells >200/ µL and I1 = CD4 cells <200 µL) and S for systemic illness (S0 = no history of opportunistic infections, S1 = history of opportunistic infections and thrush) Patient Sex Age Ethnicity Kaposi stage (TIS) Follow‐up time since KS diagnosis Visceral involvement Bone lesion (imaging) HHV8 viremia at KS diagnosis (full blood c/mL) Chemotherapy (first line, number of cycles, time period) Last HIV‐RNA (c/µL) ART including PI (y/n) Special comment A M 47 (1965) CAU 1/1/1 10 years yes Axial skeleton, disseminated, hypodense (CT scan) n.a. Liposomal Doxorubicin (13, 1999–2004) < 20 yes DXA‐scan BMD within normal range B M 45 (1969) SSA 1/1/1 8 months Yes Axial skeleton, disseminated, hypodense (CT scan) 2200 Paclitaxel (4, 2012–ongoing) 45 yes KS confirmation by bone biopsy C M 41 (1971) SSA 1/0/1 5 years Yes Axial skeleton, disseminated, hypodense (CT scan) Not done none 94 no D M 39 (1973) SSA 1/1/1 6 months Yes Axial skeleton, single lesions, hypodense (CT scan) 62200 Paclitaxel (3, 2012–ongoing) < 20 yes (but stop May 2012) (Abbreviations: SSA = Sub Saharan Africa; CAU = Caucasian; n.a.=not available DXA = Dual‐energy X‐ray absorptiometry; BMD = bone mineral density)

Sirolimus for the Treatment of Kaposi Sarcoma After Renal Transplantation: A Series of 10 Cases

The incidence of Kaposi sarcoma (KS) has substantially increased among immunocompromised patients, suggesting a role for immunosuppressive drugs. The aim of this study was to evaluate the incidence, features, and outcome of KS among 307 kidney transplantation patients at our center between January 1994 and June 2010. During the study period, the 10 patients who developed KS (3.25%) showed a mean age at transplantation of 35.8 ± 8.7 years (range, 22 to 49 years). The mean interval between transplantation and occurrence of KS was 24.7 ± 21.36 months (range, 6 to 64 months). The mean time of antithymocyte globulin induction was 9.5 days (range, 6 to 13 days). KS was restricted to the skin in 7 cases, among which, one presented with associated Hodgkin lymphoma. Visceral involvement (one lung and one colon) was observed in two cases. One patient presented with a gastric KS without skin lesions. Immunosuppressive treatment was reduced, then withdrawn in three cases, resulting in regression of KS a few weeks later, but with graft loss requiring hemodialysis at 1, 3 and 4 months. Among the remaining 7 cases, we stopped mycophenalate mofetil (MMF) and switched from calcineurin inhibitors to sirolimus. Allograft function remained stable after the switch. Only one patient who already had allograft dysfunction due to biopsy-proven chronic allograft nephropathy. Deteriorated progressively, undergoing hemodialysis at 2 years after KS diagnosis. In conclusion, we observed a relatively high incidence of KS among our cases. The introduction of sirolimus resulted in complete regression of KS lesions with preserved graft function.

Anogenital Lesions: Kaposi's Sarcoma and Its Mimicks

Kaposi's sarcoma (KS) is a low-grade vascular neoplasm associated with human herpes virus-8 (HHV-8) infection, and, in the epidemic form, with the human immunodeficiency virus (HIV). Although HHV-8 is present in all body fluids and is sexually transmitted, there are surprisingly few reports of anogenital KS. Clinically, especially in HIV/KS endemic areas, dark stained skin patches or nodules are prone to misdiagnosis, especially in dark-skinned individuals. Therefore, a biopsy is recommended. The histologic appearance spans a broad spectrum of KS and non-KS lesions; therefore, the final diagnosis should be confirmed by HHV-8 immunohistochemistry. We report a series of 36 anogenital biopsies from a group of 16 documented HIV-positive patients; in 20 the HIV serostatus was unknown. There were ten KS (five in HIV-positive patients), and 26 non-KS (11 in HIV-positive subjects) lesions. In the era of HIV/AIDS, anogenital lesions may be the first manifestation of KS in immunocompromised individuals and should be biopsied. The histological diagnosis should be confirmed by HHV-8 immunohistochemistry.

Upregulation of human β-defensin-3 and cathelicidin LL-37 in Kaposi’s sarcoma

Background: Kaposi’s sarcoma (KS) is a rare neoplasm of lymphatic endothelial cells. Human herpes virus 8 (HHV-8) is considered to be a necessary, but not sufficient causal agent of KS and additional cofactors remain unknown. In this study we evaluated the expression of human β defensin (HBD)-3 and LL-37 in cutaneous lesions of KS in comparison to the healthy skin of normal subjects. Methods: We performed a quantitative immunohistochemical study of HBD-3 and LL-37 on skin lesions from 18 patients having KS, and on healthy skin from 12 normal controls. Results: HBD-3 and LL-37 were significantly upregulated in epidermal and dermal specimens of all KS patients in comparison to normal skin of healthy controls. The immunostaining score of dermal HBD-3 was significantly higher in nodular lesions (9.6 ± 2.4) versus plaque lesions (4.1 ± 2.2), P = 0.001. Also the immunostaining score of dermal LL-37 was significantly higher in nodular lesions versus plaque lesions (P = 0.001). Conclusions: We have demonstrated for the first time that HBD-3 and LL-37 are significantly upregulated in lesional skin of KS in comparison to the skin of healthy controls. The obtained data suggest a possible involvement of these antimicrobial peptides in the pathogenesis of KS. However, the biological significance of HBD-3 and LL-37 in KS lesions needs further research.

Detection of human herpesvirus 8 by quantitative polymerase chain reaction: development and standardisation of methods

BackgroundHuman herpesvirus 8 (HHV-8), the aetiological agent of Kaposi’s sarcoma (KS), multicentric Castleman’s disease (MCD), and primary effusion lymphoma (PEL) is rare in Australia, but endemic in Sub-Saharan Africa, parts of South-east Asia and Oceania. While the treatment of external KS lesions can be monitored by clinical observation, the internal lesions of KS, MCD and PEL require extensive and expensive internal imaging, or autopsy. In patients with MCD and PEL, if HHV-8 viraemia is not reduced quickly, ~50% die within 24 months. HHV-8 qPCR is a valuable tool for monitoring HHV-8 viraemia, but is not available in many parts of the world, including those with high prevalence of KS and HHV-8.MethodsA new molecular facility with stringent three-phase workflow was established, adhering to NPAAC and CLSI guidelines. Three fully validated quantitative assays were developed: two for detection and quantification of HHV-8; one for GAPDH, necessary for normalisation of viral loads in tissue and peripheral blood.ResultsThe HHV-8 ORF73 and ORF26 qPCR assays were 100% specific. All qPCR assays, displayed a broad dynamic range (102 to 1010 copies/μL TE Buffer) with a limit of detection of 4.85x103, 5.61x102, and 2.59x102 copies/μL TE Buffer and a limit of quantification of 4.85x103, 3.01x102, and 1.38x102 copies/μL TE Buffer for HHV-8 ORF73, HHV-8 ORF26, and GAPDH respectively.The assays were tested on a panel of 35 KS biopsies from Queensland. All were HHV-8 qPCR positive with average viral load of 2.96x105 HHV-8 copies/μL DNA extract (range: 4.37x103 to 1.47x106 copies/μL DNA extract): When normalised these equate to an average viral load of 2.44x104 HHV-8 copies/103 cells (range: 2.20x102 to 7.38x105 HHV-8 copies/103 cells).ConclusionsThese are the first fully optimised, validated and MIQE compliant HHV-8 qPCR assays established in Australia. They worked well for qualitative detection of HHV-8 in archival tissue, and are well-suited for quantitative detection in whole blood. They are now available for research, for clinical diagnosis of HHV-8 infection, and for monitoring treatment efficacy.

Gene Expression Profiling Associated with the Progression of Classic Kaposi's Sarcoma

Although Kaposi's sarcoma (KS) gene expression profile is closer to lymphatic (LEC) rather than blood vascular endothelial cells (BEC), uncertainty still surrounds the cellular origin of KS. To follow KS progression from early to late (nodular) stage, and characterize the molecular fingerprinting associated with each stage, gene arrays were used to compare gene expression profile of 9 skin samples of classic KS (4 Early, 2 Mixed, and 3 Nodular CKS samples) to 4 normal samples. Results for selected genes were validated by Real-time (RT) PCR and immunohistochemistry. Genes regulating immune and defense responses, angiogenesis, apoptosis and proliferation were differentially expressed in different KS stages compared to normal skin. Hierarchical clustering separated normal skin from KS with a clear gradient from early to nodular KS lesions. The gene expression level of endothelium markers, metalloproteinases, angiogenic factors and chemokines, gradually increased from normal through all KS stages. The expression of LEC genes highly increased from early to nodular KS. In the initiation phase we noticed a higher expression of growth factors, as compared to progressive stages. LEC and BEC markers co-exist in “KS expression signature”, although the LEC signature prevailed. Our results also show a complex environment of inflammatory cells and chemokines during KS evolution. A pathogenic hypothesis where cellular hyperproliferation is driven by local expression of chemokines and growth factors without clonal expansion of cells is suggested.

Beneficial course of two cases of HIV-associated multicentric Castleman disease treated with HIV antiretroviral therapy

Beneficial course of two cases of HIV-associated multicentric Castleman disease treated with HIV antiretroviral therapy

The ephrin receptor tyrosine kinase A2 is a cellular receptor for Kaposi's sarcoma–associated herpesvirus

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma(1), a highly vascularized tumor originating from lymphatic endothelial cells, and of at least two different B cell malignancies(2,3). A dimeric complex formed by the envelope glycoproteins H and L (gH-gL) is required for entry of herpesviruses into host cells(4). We show that the ephrin receptor tyrosine kinase A2 (EphA2) is a cellular receptor for KSHV gH-gL. EphA2 co-precipitated with both gH-gL and KSHV virions. Infection of human epithelial cells with a GFP-expressing recombinant KSHV strain, as measured by FACS analysis, was increased upon overexpression of EphA2. Antibodies against EphA(2) and siRNAs directed against EphA2 inhibited infection of endothelial cells. Pretreatment of KSHV with soluble EphA2 resulted in inhibition of KSHV infection by up to 90%. This marked reduction of KSHV infection was seen with all the different epithelial and endothelial cells used in this study. Similarly, pretreating epithelial or endothelial cells with the soluble EphA2 ligand ephrinA4 impaired KSHV infection. Deletion of the gene encoding EphA2 essentially abolished KSHV infection of mouse endothelial cells. Binding of gH-gL to EphA2 triggered EphA2 phosphorylation and endocytosis, a major pathway of KSHV entry(5,6). Quantitative RT-PCR and in situ histochemistry revealed a close correlation between KSHV infection and EphA2 expression both in cultured cells derived from human Kaposi's sarcoma lesions or unaffected human lymphatic endothelium, and in situ in Kaposi's sarcoma specimens, respectively. Taken together, our results identify EphA2, a tyrosine kinase with known functions in neovascularization and oncogenesis, as an entry receptor for KSHV.