Kaposi’s Sarcoma

Kaposi’s Sarcoma

Kaposi’s Sarcoma in Renal-transplant Recipients: Experience at the Catholic University in Rome, 1988-1996

Introduction.—The main cause of increased incidence of malignancies in organ transplant recipients is immunosuppressive therapy. Posttransplant Kaposi’s sarcoma (KS), which is responsible for 3.4% of malignancies in recipients of renal transplants, may regress spontaneously when immunosuppressive drugs are decreased or withdrawn. The clinical char-acteristics of KS observed between 1988 and 1996 in transplant recipients were examined.

Methods.—Three hundred two renal transplant recipients were followed in the 8-year period. Skin lesions were biopsied and underwent histologic examination and staging workup when KS was suspected.

Kaposi’s SarcomaResults.—Ten of 302 renal transplant recipients received a diagnosis of KS. Four of 10 were on triple drug therapy including cyclosporine, meth ylprednisolone and azathioprine. All patients tested negative for HIV. The range of onset of KS after transplant was 3 months to 4 years (21.1 months). Kaposi’s sarcoma was limited to the skin in 6 patients and involved the internal organs in the remaining 4 patients. Complete remission of KS was observed in 4 patients in whom immunosuppressive therapy was reduced.

Conclusion.—The incidence of KS (2.98%) in this cohort of patients studied at the Catholic University in Rome was high, compared to other reports. It may be that genetic disposition plays a pathogenetic role. All patients with KS were from central or Southern Italy, where KS is not uncommon.

► The relatively early occurrence (3 months to 4 years) of KS after trans-plantation is striking. The relatively high incidence of the disorder in these patients likely represents a genetic disposition to KS in this population. As has been previously reported, patients may experience remission of the disease after reduction or discontinuation of immunosuppressive therapy.

Disseminated Kaposi’s Sarcoma After Long-term Prednisone Therapy

Introduction.—Kaposi’s sarcoma (KS) may occur iatrogenically in immunosuppressed patients, particularly organ transplant recipients who are treated systemically with corticosteroids and other immunosuppressive agents. Reported is the occurrence of disseminated KS in a patient with long-term steroid therapy for bronchial asthma.

Case Report.—Woman, 63, was seen for painful, disseminated skin lesions on the limbs. She had been treated with prednisone 15-60 mg daily since 1958 for bronchial asthma. She was diagnosed with steroid-induced diabetes mellitus in 1984. In 1979, she was diagnosed with disseminated osteoporosis and had multiple pathological fractures. Dermatologic examination revealed multiple hard, painful red-violet nodules and infiltrates that merged into larger irregular plaques. The lesions were initially on the arms and legs and then developed on the tongue and upper margins of the eyelids. She had lymphoedema of the hands and legs. Biopsies revealed normal epidermis, but the dermis was replaced by numerous dilated, thin-walled vascular spaces, which were lined by endothelial cells and filled with erythrocytes that also were present in perivascular tissue. Her CMV antibody titer was 1:32,000. The ratio of CD-4 to CD-8 was reversed in January 1994 and March 1995 and the CD-22 level was significantly decreased. She received 4 treatment schedules of chemotherapy. Exacerbation of severe bronchial asthma each time prednisone was decreased made treatment difficult. She did not respond to cytostatic therapy. Predni-sone dose was able to be reduced to 50% after COP chemotherapy.

Conclusion.—The 35-year history of steroid therapy for bronchial asthma probably caused immunologic abnormalities. Immunosuppression induced by prednisone is a risk factor for KS, which may be experienced by genetically susceptible individuals.

► The occurrence of KS in immunosuppressed individuals is consistent with its presumed infectious cause. Recent work has suggested that many cases of KS are caused by HHV-8. Is KS a true neoplasm, or simply a reactive disorder? Some patients with KS occurring in the setting of pharmacologic immunosuppression note resolution of lesions when the immunosuppressive drugs are discontinued.

Molecular Analysis of Clonality in Kaposi’s Sarcoma

Introduction.—Kaposi’s sarcoma (KS) is an angioproliferative disease related to a novel herpesvirus (KSH/HHVS). The precise pathophysiology of the lesion is unknown. Clonality is an important feature of neoplastic lesions and the absence of clonality is indicative of reactive hyperplasia. The prevalence of KS lesions in males has made it difficult to evaluate clonality using X-linked DNA polymorphism. A recently developed nonradioactive and quantitative clonality assay allows analysis to be performed in at least 70% of an unselected female population. This methodology was used in 7 females with KS.

Methods.—All 7 females underwent punch biopsies. An assay based on a methyl sensitive restriction digest with subsequent polymerase chain reaction amplification of the highly polymorphic human androgen receptor (HUMARA) gene was employed. The tissues from 4 females with classic KS and 3 with AIDS-associated KS were compared with control tissues from the same patients. A cutaneous angiosarcoma was also examined for comparison and for evidence of clonality after Hpall digestion.

Results.—All 7 females were heterozygous for the HUMARA polymorphism and informative for analysis. A polyclonal pattern of inactivation was observed in all patients, including 4 with nodular KS and more than 70% spindle cells in the lesion. In the cutaneous angiosarcoma, DNA was extracted and used as a monoclonal control and to confirm the ability to detect clonal populations from skin tumors. This analysis demonstrated a typical clonal pattern, whose index value was 19.3.

Conclusion.—These findings provide indirect molecular evidence that most cells involved in the KS lesion are polyclonal.

Kaposi’s SarcomaImmunohistochemical Analysis of Procathepsin L and Cathepsin B in Cutaneous Kaposi’s Sarcoma

Introduction.—Cathepsins L and B are proteinases found in many normal cells and tissues. Their major role is intracellular protein catabolism and turnover. They may also have an active role in tumor progression in vivo. High levels of cathepsin L and B have been detected in many human tumors. The expression of procathepsin L and cathepsin B was evaluated in AIDS-associated and non-AIDS-associated Kaposi’s sarcoma (KS).

Methods.—Skin biopsy specimens of KS lesions taken from 29 male patients (24 HIV-positive and 5 HIV-negative) between 1985 and 1993 underwent immunohistochemical analysis. Procathepsin L and cathepsin B were assessed. The tissues were formalin-fixed and paraffin-embedded, then immunolabeled with the polyclonal antibody directed against pro-cathepsin L and the antisera directed against cathepsin B.

Results.—Both cathepsins were expressed in normal epidermis, eccrine sweat glands, and hair follicle tissues. Positive staining for procathepsin L was detected in normal blood vessels. Neither enzyme was expressed in “angiomatous” or “fibroblastic” lesions of KS.

Conclusion.—The absence or down-regulation of procathepsin L and cathepsin B in AIDS-associated and non-AIDS-associated KS suggests that these tumors have no potential to invade or metastasize. These lesions are probably not neoplasms. They may be a reversible hyperplasia with a tendency for spontaneous regression.

► In patients with KS who receive renal transplants, lowering the dose of immunosuppressant drugs or discontinuing them can lead to spontaneous involution of the KS lesions. This clinical observation suggests that KS is a reactive hyperplasia and not a true neoplasm. The study by Delabesse et al. (Abstract 20-3), utilizing molecular techniques, indicates that KS, both in its classic form and in the AIDS-associated form, is a polyclonal cell proliferation. This does not preclude the possibility of clonal evolution late in the disease process but suggests that KS is a reactive hyperplasia. The study of Thewes et al. (Abstract 20-4) also supports a benign autochthonous origin of KS lesions. The lack of expression of procathepsin L and cathepsin B in the lesions of both AIDS-associated and classic KS suggests that they are reactive hyperplasias.

Expression of HHV-8 Latency-associated T0.7 RNA in Spindle Cells and Endothelial Cells of AIDS-associated, Classical and African Kaposi’s Sarcoma

Introduction.—Usually a multifocally developing tumor with distinct cutaneous and visceral lesions, Kaposi’s sarcoma is characterized by a prominent vascular component in a stroma of spindle-shaped cells. The cause of Kaposi’s sarcoma may be a sexually transmitted infectious agent. Previous studies have found a novel human herpes virus-8 (HHV-8) that was isolated from AIDS-associated Kaposi’s sarcoma, indicating that this virus may have an important role in the pathogenesis of Kaposi’s sarcoma. The expression of a recently described 0.7-kb HHV-8-encoded messenger RNA (T0.7 mRNA) in Kaposi’s sarcoma tissues of different epidemiologic origin was investigated to clarify the role of HHV-8 in Kaposi’s sarcoma.

Methods.—Twelve biopsy specimens of Kaposi’s sarcoma were examined, including those of 3 homosexual male patients. Tissues of various epidemiologic origins were used including AIDS-type Kaposi’s sarcoma, African endemic Kaposi’s sarcoma, and classic Kaposi’s sarcoma. Cells were cultured and in situ hybridization was carried out to explore the role of T0.7 mRNA.

Results.—Supposedly expressed in latently HHV-8-infected cells, the T0.7 mRNA likely encodes a small membrane protein. Late-stage Kaposi’s sarcoma tissues (nodular) showed a high level of T0.7 mRNA expression in typical Kaposi’s sarcoma spindle cells in all Kaposi’s sarcoma biopsy specimens of all epidemiological origins examined. Latent HHV-8 infection of these cells was indicated by a high level of T0.7 mRNA expression found in endothelial cells lining blood vessels. T0.7 mRNA was also detected in virtually all cells of the cell line body cavity-based lymphoma-I established from a body cavity-based lymphoma and latently infected with HHV-8.

Conclusion.—There seems to be an important role for latent HHV-8 infection in Kaposi’s sarcoma pathogenesis based on the finding of T0.7- expressing cells restricted to Kaposi’s sarcoma tumor tissue.

► Recent studies have shown HHV-8 in the lesions of Kaposi’s sarcoma. All epidemiologic types of Kaposi’s sarcoma have been associated with this virus. In this study, the authors used in situ hybridization to show that HHV-8 was present in a latent state in the lesions of Kaposi’s sarcoma. The virus was more prevalent in advanced lesions of Kaposi’s sarcoma and was found in both spindle and endothelial cells. It was not present in the surrounding skin, suggesting that HHV-8 might be a facilitator rather than an initiator.

Detection of Human Herpesvirus 8 and Human T-Cell Lymphotropic Virus Type 1 Sequences in Kaposi Sarcoma

Introduction.—Though long suspected, no infectious cause of Kaposi sarcoma (KS) has been demonstrated. In ultrastructural studies, retroviral particles have been found in KSs related and unrelated to HIV infection. Recent studies have shown DNA sequences from a new virus, human herpesvirus 8 (HHV-8), in KS tissues. Human herpesvirus 8 sequences were studied in a large series of non-HIV-related KS specimens. The study also correlated the presence of HHV-8 sequences with clinical staging data, and screened for human T-cell lymphotrophic virus type 1 (HTLV-1) sequences in the peripheral blood mononuclear cells (PBMCs) of affected patients.

Methods.—The study included 31 patients with confirmed KS but no evidence of HIV infection. Most represented classic cases of KS. Disease stage was I in 13 patients, II in 8 patients, III in 7 patients, and IV in 3 patients. Human herpesvirus 8 sequences were sought in 28 PBMC samples using a simple polymerase chain reaction (PCR) with 2 sets of primers, and with a nested PCR in 12 samples. Testing for HTLV-1 was performed in 19 patients.

Results.—Human herpesvirus DNA was found in all KS specimens. In PBMC samples, it was found in 32% of samples tested by the simple PCR reaction and 42% of those tested by the nested PCR method. The results were similar when a higher amount of DNA was used. The positivity rate for HHV-8 sequences in PBMCs was 28% for patients with stage I or II KS versus 70% for those with stage III or IV. The detection rate of HHV-8 in normal skin samples was 70%, regardless of the extent of disease. Eleven percent of patients had detectable HTLV-1 pX sequences in their PBMCs; no gag, pol or env sequences were detected. In 1 patient with detectable HHV-8 sequences in KS tissue, PCR for HTLV-1 pX was negative in both KS and normal homologous skin tissue.

Conclusions.—This study finds no significant association between non- HlV-related KS and infection with HTLV-1. However-HHV-8 does appear to be significantly associated with such KSs, and may play an important pathophysiologic role. Normal skin samples from most patients with non-HFV-related KS show HHV-8, regardless of the extent of disease. However, the detection of HHV-8 in PBMCs may be related to tumor burden. The authors are performing a study to see if interferon-alpha treatment affects the detection of HHV-8 in PBMCs and normal, uninvolved skin.

► It has been well established that HHV-8 is associated with KS in a variety of clinical settings. In this study of 31 patients with KS not associated with HIV infection, the authors used the PCR to detect evidence of HHV-8 infection in 100% of biopsy specimens of lesional skin, 70% of distant normal skin samples, and in the PBMCs of 42% of patients. The presence of HHV-8 in the PBMCs correlated with more extensive mucocutaneous involvement. Although evidence of HTLV-1 infection was detected in the PBMCs of 2 patients, PCR analyses showed that this virus did not seem to play a role in the pathogenesis of KS. The finding of HHV-8 in normal skin and PBMCs confirms what clinicians have known for years, i.e., the disease is multicentric in origin. Although local therapies (e.g., intralesional vinblastine, radiation therapy, and laser surgery) have been shown to be effective in eradicating a given lesion, it would appear, based on accumulating data, that the only way to truly cure a patient of KS is with systemic therapy.

Hyaluronidase Enhances the Therapeutic Effect of Vinblastine in Intralesional Treatment of Kaposi’s Sarcoma

Objective.—Intralesional vinblastine and vincristine treatment of Kaposi’s sarcoma (KS) is frequently very uncomfortable and has left residual tumor. Local injection of hyaluronidase potentiates dispersion of drugs through tissue for 24-48 hours without initiating an allergic reaction except in rare circumstances.

Methods.—Six male patients, age 27-48, with multiple KS plaques and nodules at least 2.5 cm in diameter, including 2 patients with recurrences after treatment with radiation, and with T4 levels less than 200/μL, were treated with intralesional vinblastine (0.2 mg/cm2 surface area for plaques and 0.4 mg/cm2 surface area for nodules) preceded by 1% lidocaine with epinephrine 1/100,000 with or without hyaluronidase 150 turbidity reducing units (TRU)/3 mL.

Results.—Vinblastine with and without hyaluronidase caused regression of KS lesions and hyperpigmentation, but the combination was more effective in treating nodules. No lesions cleared by the combination recurred. Superficial bullae more frequently occurred in lesions treated with hyaluronidase. More than 50% of lesions treated with vinblastine alone recurred.

Discussion.—Because KS is seen mainly in patients with late-stage AIDS, most patients are no longer candidates for systemic therapy. Other therapies, radiation, cryotherapy, intralesional chemotherapy, and immunotherapy, can leave residual tumor beneath the scar. Intralesional interferon-α requires multiple treatments and high doses and has been used mainly to treat small lesions. Tumor nodules treated with vinblastine tend to respond incompletely and recur. In addition to potentiating the effect of vinblastine, hyaluronidase also potentiates the effect of anesthesia and lowers the incidence of recurrence.

Conclusion.—Intralesional vinblastine combined with hyaluronidase yielded superior results compared with vinblastine alone, particularly for larger lesions. The combination also lowered the recurrence rate.

► Although the number of patients in this study was small, the authors felt that a combination of intralesional vinblastine and hyaluronidase yielded superior results compared to intralesional vinblastine alone. This was especially true for larger lesions, which responded better and were less likely to recur.