Human immunodeficiency virus-associated neoplasms: epidemiology, pathogenesis, and review of current therapy

The development of cancer in the setting of human immunodeficiency virus (HIV) infection is a devastating event and highlights the role of impaired immunity in the generation of various neoplasms. Improved strategies to suppress viral replication and prevent opportunistic infections generally have enabled patients with HIV to live longer and more productively. Unfortunately, acquired immune deficiency syndrome (AIDS)-associated neoplasia is increasing. Kaposi's sarcoma (KS), primary central nervous system lymphoma, intermediate- and high-grade B-cell lymphoma, and invasive cervical carcinoma are AIDS-defining conditions and the most commonly encountered malignancies. Recent information suggests an indirect role for HIV in the pathogenesis of these tumors. Effective treatment involves addressing complex variables encountered specifically in patients with AIDS. This review focuses on the epidemiology, pathogenesis, and treatment of KS and non-Hodgkin's lymphoma.

Four varied cases of intravascular lymphomatosis and a literature review

BACKGROUND

Intravascular lymphoma (IVL) is an uncommon malignancy defined pathologically by neoplastic proliferation of lymphoid cells within the lumens of capillaries, small veins, and arteries, with little or no adjacent parenchymal involvement. The nature of IVL has been the subject of considerable controversy. Recent immunohistochemical studies have demonstrated clearly that the tumors bear the immunophenotype of neoplastic lymphoid cells of either B-cell or T-cell lineage. IVL commonly affects the central nervous system, resulting in progressive dementia and multiple neurologic deficits; skin is the second most common site of involvement, in the form of cutaneous plaques and nodules.

METHODS

In a retrospective review of all cases of non-Hodgkin's lymphoma seen at our institution, four cases of IVL were identified. Case 1 was fixed in methacarin, and Cases 2-4 were fixed in 10% formalin. Standard fixation, tissue processing, sectioning, and hematoxylin and eosin staining were used. Immunophenotypic studies were performed using a modified avidin-biotin complex technique. The specimen in Case 1 was stained by Giemsa stain using standard techniques.

RESULTS

Four cases of IVL are presented. One patient experienced hypoxemia and fevers of unknown origin; the second, dementia and a vasculitislike illness; the third rapidly progressive dementia, nonlocalizing neurologic deficits, and panhypopituitarism; the fourth Kaposi-like skin lesions. Case 1 relapsed shortly after completing chemotherapy. Salvage chemotherapy has yielded good initial response. Autopsy findings in cases 2, 3 and 4 confirmed IVL in many vessels, including the brain, lung, liver, heart, gastrointestinal tract, glomerulus, central nervous system, and skin. Malignant lymphoid cells marked as B-cells in all cases.

CONCLUSIONS

Unusual and interesting clinical presentations may occur in patients with IVL. The medical literature indicates that few cases are diagnosed ante mortem. Although isolated patients may respond favorably to chemotherapy, most will deteriorate rapidly and the diagnosis of IVL not contemplated until necropsy.

Human T cell leukemia virus (HTLV-I/II) serodiagnostic testing: disparate results among a cohort of intravenous drug users

Three hundred and forty-six sera collected over a 2-year period from 154 San Francisco IV drug users were subjected to HTLV-I/II RIPA, Western blot (WB), Du Pont ELISA, and p24 radioimmunoassay (RIA). Tests were performed at separate sites and code not broken until study end. RIPA-positive and -negative controls consisted of Japanese adult T cell leukemia patients, healthy blood donors, and non-IV drug-using HIV-positive men. RIPA identified HTLV-I/II-positive sera not identified by the other tests. Positive RIPAs were noted in 43% of negative ELISAs (n = 279), 34% of negative WBs (n = 243), and 40% of negative RIAs (n = 270). Seventy-two sera were negative by all 3 assays, but were RIPA positive. All sera positive by RIA (n = 76) and WB (n = 67), and 66 of 67 by ELISA, were positive by RIPA. Thirty-five of 36 indeterminate WBs were RIPA positive. Seven samples indeterminate by RIPA were negative by WB and RIA; one of seven was positive by ELISA. In all instances, samples negative by RIPA (n = 154) were ELISA, p24 RIA, and WB negative or indeterminate. We conclude that when studying HTLV-I/II-endemic cohorts, screening ELISA or RIA followed by confirmatory WB or RIPA only of seropositive samples may result in a substantial number of undetected cases. Additional studies focusing on performance characteristics of serodiagnostic tests are needed to ensure accurate inferences are made in assessing HTLV-I/II prevalence rates among high-risk groups. The RIPA may be a uniquely sensitive assay to detect HTLV-I/II gene-encoded products.

Carcinocythemia. A terminal manifestation of metastatic breast cancer

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Case report: thrombotic thrombocytopenic purpura in a patient with polymyositis: therapeutic importance of early recognition and discussion of pathogenic mechanisms

Thrombotic thrombocytopenic purpura (TTP) is characterized by the pentad of fever, thrombocytopenia, microangiopathic hemolytic anemia, fluctuating neurologic symptoms, and renal dysfunction. Thrombotic thrombocytopenic purpura has recently been reported in association with rheumatic diseases (RDs). The authors present a patient with TTP and polymyositis and speculate on the pathophysiology linking these two conditions. Thrombotic thrombocytopenic purpura and RDs may present with overlapping clinical and laboratory features. It is important to identify TTP as a cause of thrombocytopenia and hemolysis when occurring in patients with RDs since management, treatment, and prognosis differ. Early recognition and prompt institution of plasmapheresis may improve the outcome in patients with TTP.

Human T-cell leukemia virus type-I/II (HTLV-I/II) serologic testing: the importance of assaying for the full complement of viral antigens

Seventy-one Japanese adult T-cell leukemia (ATL) patients and 411 Japanese asymptomatic patients from HTLV-I endemic regions of southern Japan were found to be seropositive by radioimmunoprecipitation assay (RIPA). Of these 482 positive controls, 62% of ATL patients and 67% of the asymptomatic seropositive patients were found to harbor antibodies to p40x. Additionally, 333 preselected Japanese blood donors who were identified as seropositive by particle agglutination (PA) assay were further tested for antibodies to HTLV-I/II gene encoded envelope (env) or group specific antigens (gag) by means of enzyme-linked immunosorbent assay (ELISA) and RIPA. Concordance between ELISA and RIPA was noted in 318 samples (92.5%). Discordance between ELISA and RIPA was observed in 15 sera (7.5%)--2 were seropositive by ELISA and seronegative by RIPA and 13 were seronegative by ELISA and seropositive by RIPA. Seven of these 13 samples (53.8%) contained antibodies to p40x by RIPA and may represent ELISA false negatives on the basis of both clinical and laboratory data. Current HTLV-I/II ELISA kits may yield false negative results. Additional research into the development of rapid detection cost-efficient assays that test for the full compliment of viral antigens is needed.

Hematologic abnormalities in AIDS

The hematologic manifestations of HIV infection include morphologic abnormalities of peripheral blood and bone marrow changes. Laboratory abnormalities, including measures of coagulation, serum vitamin B12 levels, and positive Coombs's test, are seen with HIV infection and may not carry the same clinical consequence as when noted in non-HIV infected populations. Antibodies to circulating red blood cells, platelets, and granulocytes may represent alterations in autoimmunity or nonspecific HIV-induced B-cell stimulation, but they do not necessarily correlate with development of peripheral blood cytopenias. The advent of commercially available hematopoietic growth factors has allowed greater insight into specific host-virus-drug interactions that may be important in regulating viral growth and expression. Novel clinical approaches using hematopoietins alone or in combination with antimicrobial, antiviral, and antitumor drugs represent exciting developments in the treatment of HIV infection.

Human T-cell leukemia virus infection in non-intravenous drug using HIV seropositive men in Los Angeles

Sera from 634 homosexual men with Western blot-confirmed human immunodeficiency virus (HIV) infection were subjected to radioimmunoprecipation assay (RIPA) using an HTLV-I-infected human T-cell line (SLB-I). Sera obtained from Japanese adult T-cell leukemia patients, noninfected healthy individuals served as positive and negative controls. HIV-infected groups were comprised of asymptomatic homosexuals (n = 131), AIDS-related complex (n = 115), Kaposi's sarcoma (n = 300), AIDS-defining opportunistic infections (n = 76), and high-grade lymphomas (n = 12). Only two patients were known to be intravenous drug users. No instances of dual retroviral infection were detected. As a corollary, no cross reactivity between HTLV and HIV gene products was noted by RIPA. We conclude that HTLV infection is uncommon among select groups of HIV seropositive homosexuals who do not engage in intravenous drug abuse. Additional studies examining the seroprevalence and consequence of HTLV infection in broader based populations at risk for retroviral infection are required.

A patient with progressive myelopathy and antibodies to human T-cell leukemia virus type I and human immunodeficiency virus type 1 in serum and cerebrospinal fluid

A 52-year-old human immunodeficiency virus type 1-seropositive bisexual black man was evaluated at UCLA because of the recent onset of progressive lower-extremity weakness. Initial neurologic examination showed that the patient's distal weakness was greater than his proximal weakness, with bilateral foot drop and electrophysiologic evidence of denervation in the distal lower extremities. Magnetic resonance imaging of the brain and spinal cord disclosed no abnormalities. Subsequent neurologic evaluation 8 months later showed a myelopathy, with progression of lower-extremity weakness, spasticity, and flexor spasms, and urinary incontinence, as well as the peripheral neuropathy noted previously. A second magnetic resonance imaging scan of the brain showed patchy foci of increased signal intensity in white matter and cortex, with mild generalized cerebral and cerebellar atrophy and no lesions in the spinal cord. Specimens of the patient's serum and cerebrospinal fluid contained antibodies to human immunodeficiency virus type 1. Additionally, specimens of his serum and cerebrospinal fluid were tested for antibody to human T-cell leukemia virus type I by Western blotting and radioimmunoprecipitation, and found to be positive for human T-cell leukemia virus type I gag, env, and tax antibodies. The primary cause of severe myelopathy in this patient may be infection with human T-cell leukemia virus type I rather than with human immunodeficiency virus type 1. Treatment with prednisolone resulted in improvement of the lower-extremity weakness, reduction in flexor spasms, and slower but significant improvement in urinary symptoms. Patients who are infected with human immunodeficiency virus type 1 and have unusual motor findings should be tested for concomitant human T-cell leukemia virus type I infection.