Cutaneous CD8 T cell infiltrates in advanced HIV infection

Immunocytochemistry and the diagnosis of cutaneous lymphoma

Cutaneous lymphoid infiltrates may pose some of the most difficult diagnostic problems in dermatopathology. Immunocytochemistry is often employed in an effort to determine whether an infiltrate is neoplastic or, in the case of clearly malignant infiltrates, to provide a specific diagnosis. The rarity of these disorders and the variant immunocytochemical profiles they may present further thwart understanding and sometimes prevent an accurate diagnosis. In this review the common immunocytochemical profiles of various cutaneous lymphomas are presented and potential pitfalls and problems considered. Immunocytochemistry is not a diagnostic test but, as in other areas of histopathology, is a highly valuable tool that requires critical interpretation within a context: so applied, it is an indispensable part of the pathologist's arsenal in evaluating lymphoid infiltrates and defining different lymphomas.

Dermatopathological challenges in the human immunodeficiency virus and acquired immunodeficiency syndrome era

The histopathological assessment of cutaneous lesions is critical to the definitive diagnosis of many human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome-associated dermatoses, infections and tumours. Dermatopathological challenges stem mainly from the altered histopathological profile of established cutaneous entities compared with that in the HIV-unaffected population, the emergence of new diseases and the impact of therapeutic modalities on cutaneous lesions. This review focuses on some of these diagnostic dilemmas, with emphasis on the following challenges: (i) infective diagnostic pitfalls; (ii) itchy papular skin lesions; (iii) co-lesional comorbid diseases; (iv) drug-induced disease alterations; and (v) neoplastic and pseudoneoplastic proliferations. The drug-induced alterations include highly active antiretroviral therapy-associated disease modifications.

CD8+ cutaneous T-cell lymphoma successfully treated with bexarotene: a case report and review of the literature

CD8+ cutaneous T-cell lymphoma (CTCL) is a relatively rare subset of the non-Hodgkins lymphomas. Bexarotene has been FDA-approved for the treatment of CTCL, but previous studies have been conducted on CD4+ CTL and there have been no reports about its use in CD8+ CTCL. Herein, we report on a patient whose CD8+ CTCL completely responded to treatment with bexarotene.

HIV infection and lymphoma

The incidence of lymphoma in patients with HIV infection greatly exceeds that of the general population. The increased risk for lymphoma appears related to multiple factors, including the transforming properties of the retrovirus itself, the immunosuppression and cytokine dysregulation that results from the disease, and, most importantly, opportunistic infections with other lymphotrophic herpes viruses such as Epstein-Barr virus and human herpesvirus 8. Histologically lymphomas fall into three groups: (1) those also occurring in immunocompetent patients; (2) those occurring more specifically in HIV-positive patients; and (3) those also occurring in patients with other forms of immunosuppression. Aggressive lymphomas account for the vast majority cases. They frequently present with advanced stage, bulky disease with high tumour burden and, typically, involve extranodal sites. Clinical outcome appears to be worse than in similar aggressive lymphomas in the general population. However, following the introduction of highly active antiretroviral therapy, the risk for developing lymphoma in the context of HIV infection has decreased and the clinical outcome has improved.

[Frequent and rare dermatological diseases in HIV patients]

HIV patients develop a variety of infectious and non-infectious diseases of the skin and mucous membranes. Some of these serve as indicator diseases for a weakening immune system. While none of the dermatological complications is pathognomonic, conditions such as oral hairy leukoplakia, herpes zoster, thrush, and eosinophilic folliculitis should make physicians consider the possibility of underlying HIV disease. Moreover, one has to consider HIV if these skin diseases take an atypical or severe course, or if they do not respond properly to appropriate medication. Frequent and rare dermatoses occurring in HIV infection are discussed.

Cutaneous malignancy and human immunodeficiency virus disease

Certain skin cancers occur with increased frequency or altered course in patients infected with HIV. Malignant melanoma and squamous cell carcinoma are examples of cutaneous malignancies that have a more aggressive course in patients with HIV. Others, such as basal cell carcinoma, appear more frequently in this population but do not appear to be more aggressive. The incidence of HIV-associated Kapsosi's sarcoma has markedly decreased since the advent of HIV antiretroviral therapy. Our understanding of the pathogenesis of this malignancy and its unique management issues are fully reviewed. Cutaneous T-cell lymphoma (CTCL) is rare in this population. Other types of cutaneous lymphoma and HIV-associated pseudo-CTCL are discussed. This article addresses prevention, treatment, and follow-up strategies for this at-risk population.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with the unique epidemiology, clinical course, and management of cutaneous malignancy in patients infected with HIV.

Approach to the treatment of cutaneous malignancy in HIV-infected patients

Patients infected with human immunodeficiency virus (HIV) have an increased risk of developing skin cancers. These at-risk patients may have atypical presentations and/or altered clinical courses. This article will review and discuss management issues for the following malignancies: lymphomas, malignant melanoma, basal cell carcinoma, squamous cell carcinoma, and Kaposi's sarcoma.

Tumid lupus erythematosus occurring following highly active antiretroviral therapy for HIV infection: A manifestation of immune restoration

Tumid lupus erythematosus (LE) is a relatively rare and only recently recognized subset of chronic cutaneous lupus. We report a case occurring in a male with HIV infection whereby his rash was only unmasked by immune restoration following highly active antiretroviral therapy (HAART). The phenomenon of latent inflammatory or autoimmune disease appearing following HAART is now recognized as the "immune restoration syndrome" and tumid LE has not been reported in this setting previously. Fortunately this variant of lupus does not result in scarring and is responsive to anti-malarials, allowing continuation of HAART in this patient.

Lymphomatoid papulosis in an HIV-positive man

Lymphomatoid papulosis (LyP) is a rare cutaneous lymphoproliferative condition characterized by a chronic, recurrent eruption of papules and nodules that undergo spontaneous regression. The disorder is usually clinically benign; with a minority of cases progressing to malignant lymphoma. LyP is divided into two subtypes based on histologic appearance. Type A resembles Hodgkin's disease with up to 20% of large CD30+ lymphocytes. Type B resembles mycosis fungoides showing an infiltrate of CD4+ lymphocytes and scattered CD30+ cells. Clinically LyP often resembles pityriasis lichenoides et varioliformis acuta but has a strikingly different histological appearance. Histologically, LyP resembles lymphoma (anaplastic T-cell or Hodgkin's) but is distinguished by its benign course. Here we present a case of LyP in a severely immune-repressed HIV-positive patient. This patient presented with pruritic papules involving the upper extremities and a CD4+ T-cell count of 4. Histopathologic examination showed a dense superficial dermal infiltrate comprising normal-sized lymphocytes admixed with larger lymphocytes. Immunophenotyping showed most of the lymphocytes to be CD3+ (T cells). The scattered larger cells were CD30+. The smaller lymphocytes were CD8+ rather than CD4+ as expected for non-HIV-appointed LyP. This may be because of the immune disregulation of HIV disease and the absolute and relative paucity of CD4+ T cells relative to CD8+ T cells.

Value of the CD8-CD3 ratio for the diagnosis of mycosis fungoides

Histopathological diagnosis of mycosis fungoides is difficult, especially in early lesions that may be indistinguishable from inflammatory dermatoses. Mycosis fungoides is a clonal proliferation of mature epidermotropic CD4+ lymphocytes. The aim of this study was to determine the contribution of the CD8-CD3 ratio to the diagnosis of mycosis fungoides. We retrospectively compared the immunophenotypic characteristics of 30 mycosis fungoides with 28 inflammatory dermatoses. The diagnosis of mycosis fungoides was reinforced in all cases by the presence of a cutaneous dominant T-cell clonal population. To analyze exclusively the lymphocytic infiltrates, CD4, which is also expressed by histiocytes, was not considered. The CD8-CD3 ratio was determined separately in the epidermis and the dermis using two methods, one quantitative and the other semiquantitative. Concordance rates between the two methods were higher in epidermal than dermal infiltrates. The mean CD8-CD3 ratio was significantly lower for mycosis fungoides than control cases, with the difference being greater in the epidermal than the dermal component. Although not absolutely specific, a low CD8-CD3 ratio in the epidermal component of a lymphocytic infiltrate supports the diagnosis of mycosis fungoides. It can be evaluated in routine practice using a semiquantitative approach.

Normal skin of HIV-infected individuals contains increased numbers of dermal CD8 T cells and normal numbers of Langerhans cells

Dysregulation of the skin immune system (SIS) could explain the high prevalence of skin disorders in HIV+ individuals. The present study was carried out to determine whether alterations in the cell population of SIS and epidermal immunoactivation occur in the normal skin of HIV+ individuals. Forty-five biopsies were taken from the normal upper arm skin of 45 HIV+ patients and of 15 healthy controls. HIV+ individuals were divided into three categories according to their CD4 cell blood count (<200, 200-499 and > or = 500/microl). Hematoxylin-eosin was used to stain tissue sections for morphological analysis and immunohistochemistry was used for the evaluation of the frequency of macrophages, Langerhans cells, and CD lymphocyte subsets. In addition, semiquantitative analysis of LFA-1, ICAM-1 and HLA-DR was determined in epidermal cells. Macrophages, Langerhans cells, and CD lymphocyte subsets did not differ significantly between any of the patient categories and the control group. When all HIV+ individuals were compared as a group to the control group, a significant increase in dermal CD8+ T lymphocytes (P < 0.01) and lower CD4-CD8 ratios (P < 0.01) were observed in the HIV+ individuals. Epidermal ICAM-1 and HLA-DR expression was negative in both HIV+ and normal skin biopsies. No evidence of a depletion of the SIS population or of epidermal immunoactivation in normal skin from HIV+ individuals was demonstrable, suggesting that alterations in the central immune system are not necessarily reflected in the SIS of HIV-infected patients.

Palpable arciform migratory erythema in an HIV patient, a CD8+ pseudolymphoma

BACKGROUND

Palpable arciform migratory erythema (PAME) is characterized by large, elevated, reddish annular lesions localized on the upper trunk. As its infiltrate consists predominantly of dense infiltrates of CD4+ lymphocytes with polyclonal T-cell receptor (TCR) gene rearrangement, it has been grouped as a rare member of the T-cell pseudolymphomas.

METHODS

We performed histology, immunophenotyping, and TCR-gamma gene rearrangement studies in an human immunodeficiency virus (HIV)-positive patient, CDC stage IIIB, who showed a clinically typical PAME.

RESULTS

While TCR-gamma gene rearrangement studies showed a polyclonal infiltrate confirming a pseudolymphoma, 85% of skin-infiltrating lymphocytes were CD8+ T cells.

CONCLUSION

PAME may also occur in HIV-positive patients with CD4+ deficiency. Our case demonstrates that regular CD4 counts and immunocompetence are not necessary for its pathogenesis.

Regression of CD8+ pseudolymphoma after HIV antiviral triple therapy

To our knowledge, we report the first case of improvement of HIV-associated cutaneous CD8(+) pseudolymphoma with highly active antiretroviral therapy. This favors the hypothesis of a reactive cutaneous infiltration by HIV-specific cytotoxic T cells in this disease.

Clinical and pathological spectrum of CD8-positive cutaneous T-cell lymphomas

CD8+ T-cell lymphomas presenting in the skin are rare. We describe the clinical and histological features of 18 patients with CD8+ cutaneous T-cell tumors, which have been divided into four groups. Seven patients had precedent long histories of rashes, which progressively spread in a presentation similar to that of CD4+ mycosis fungoides (MF). Three patients had long-standing localized plaques consistent with a pagetoid reticulosis (PR) pattern. Two patients presented with erythroderma and had peripheral blood involvement consistent with a Sezary syndrome (SS) pattern and had rapidly progressive clinical courses. Six patients presented with cutaneous nodules of varying sizes and had variable outcomes, with two having rapidly progressive disease, two with indolent recurrences and a further two with complete responses to treatment. Histologically, 12 of the 18 cases showed an epidermotropic tumor infiltrate that was most marked in the three PR cases. Prominent periadnexal infiltration was seen in 11 cases. Similar to CD4+ MF, the skin-homing antigen, (cutaneous lymphocyte antigen: CLA), was strongly expressed in 13 of 16 tested cases. Expression of the cytotoxic granule protein granzyme B was noted in a majority of tumor cells in only three of 16 tested cases. We conclude that approximately half of CD8+ cutaneous T-cell lymphomas clinically and histologically resemble CD4+ MF/SS, whereas presentation as discrete nodular lesions are more common in CD8+ tumors as compared to those that express CD4.

Risk of T-cell lymphomas in persons with AIDS

Lymphomas in persons with AIDS are mostly B-cell types, but T-cell lymphomas have also been reported. We examined T-cell lymphoma risk in the 2-year period after AIDS onset by linking 302,834 adults with AIDS to cancer registry data. Of 6,788 cases of non-Hodgkin's lymphoma (NHL) with specified histologies, 96 (1.4%) were T-cell lymphomas. Assessment was based on clinical diagnosis and histology because T-cell marker data were inadequate, but when present, marker data supported the T-cell diagnosis. The relative risk of T-cell lymphoma, estimated by standardized incidence ratio, was 15.0 (95% confidence interval: 10.0--21.7). Risks were increased for all subtypes, including mycosis fungoides, peripheral lymphomas, cutaneous lymphomas, and adult T-cell leukemia/lymphoma (ATLL). HIV-related immunodeficiency could be important, but differences between the population developing AIDS and the general population (e. g., immigration from the Caribbean region for ATLL) might independently increase T-cell lymphoma risk.