Human T cell leukemia/lymphoma virus type I (HTLV-I) and Pneumocystis carinii associated with T cell proliferation and haemophagocytic syndrome

Human T-lymphotropic virus 1 (HTLV-1) infection--dermatological implications

Human T-lymphotropic virus type 1 (HTLV-1) is a type C retrovirus primarily endemic to Japan, Central and South America, the Middle East, regions of Africa, and the Caribbean. Currently, an estimated 10-20 million people worldwide are infected with this virus. Although the majority of infected individuals remain asymptomatic, HTLV-1 is the causative agent of a number of disorders, notably adult T-cell leukemia/lymphoma (ATLL) and a progressive demyelinating neurological disorder, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). In addition to ATLL and HAM/TSP, HTLV-1 has been associated with a spectrum of skin disorders, such as infective dermatitis associated with HTLV-1, crusted scabies, and leprosy. The understanding of the interaction between virus and host response has improved markedly, but there are still few treatment options.

EBV-positive diffuse large B-cell lymphoma in a human T-lymphotropic virus type 1 carrier

The development of B-cell lymphomas has been seldom described in HTLV-1 carriers. We present the case of an elderly Peruvian HTLV-1 carrier who was diagnosed with EBV-positive diffuse large B-cell lymphoma. Despite an initial good response to therapy, patient died during treatment due to fatal Pneumocystis jirovecci pneumonia. EBV infection is characterized by B-cell lymphotropism and selective immunodeficiency. HTLV-1, on the other hand, induces T-cell dysfunction and B-cell proliferation. Finally, immunosenescence is characterized by T-cell dysregulation, decreased apoptosis and cytokine upregulation. In this elderly patient, the combination of EBV and HTLV-1 coinfection and immunosenescence may have played a role in the development of this aggressive diffuse large B-cell lymphoma. Furthermore, the immunodeficiency caused by the viral infections and chemotherapy may have played a role in developing life-threatening infectious complications.

Human T-lymphotropic virus 1: recent knowledge about an ancient infection

Human T-lymphotropic virus 1 (HTLV-1) has infected human beings for thousands of years, but knowledge about the infection and its pathogenesis is only recently emerging. The virus can be transmitted from mother to child, through sexual contact, and through contaminated blood products. There are areas in Japan, sub-Saharan Africa, the Caribbean, and South America where more than 1% of the general population is infected. Although the majority of HTLV-1 carriers remain asymptomatic, the virus is associated with severe diseases that can be subdivided into three categories: neoplastic diseases (adult T-cell leukaemia/lymphoma), inflammatory syndromes (HTLV-1-associated myelopathy/tropical spastic paraparesis and uveitis among others), and opportunistic infections (including Strongyloides stercoralis hyperinfection and others). The understanding of the interaction between virus and host response has improved markedly, but there are still no clear surrogate markers for prognosis and there are few treatment options.

HTLV-1-associated adult T cell leukemia lymphoma presenting as granulomatous pneumocystis jiroveci pneumonia (PJP) and hypercalcemia

BACKGROUND

Since the initial description of human T cell lymphotropic virus (HTLV-1), clusters of this infection have been detected globally. Unlike HIV infection, most patients infected with HTLV-1 remain asymptomatic throughout their lifetime.

CASE REPORT

We report the case of a 39-year-old Afro-Caribbean man with HTLV-1 infection presenting as hypercalcemia and granulomatous pneumocystis jiroveci pneumonia.

RESULTS

Interestingly, the hypercalcemia presented with normal parathyroid hormone-related protein and low 1,25 dihydroxyvitamin D levels, and the presence of pneumocystis jiroveci in the granulomas was diagnosed with transbronchial biopsy taken during bronchoscopy. HTLV-1-associated adult T cell leukemia lymphoma (ATLL) was diagnosed in this patient by bone marrow and lymph node biopsy.

CONCLUSION

Increased bone resorption, likely cytokine-mediated, is the most likely mechanism of hypercalcemia in this patient. This is believed to be the first description of this type of reaction to pneumocystis jiroveci in a HTLV-1-infected ATLL patient.

Current views in HTLV-I-associated adult T-cell leukemia/lymphoma

Epidemiological studies have demonstrated that the relative percentage of malignant lymphoid proliferations varies widely according to geographical location and ethnic populations. HTLV-I is the etiological agent of adult T-cell leukemia/lymphoma (ATLL) and is also associated with cutaneous T-cell lymphoma (CTCL). However, a definite role of HTLV-I in mycosis fungoides (MF) and/or Sezary syndrome (SS) remains controversial. While most HTLV-I-infected individuals remain asymptomatic carriers, 1-5% will develop ATLL, an invariably fatal expansion of virus-infected CD4+ T cells. This low incidence and the long latency period preceding occurrence of the disease suggest that additional factors are involved in development of ATLL. In this review, diagnosis, clinical features, and molecular pathogenesis of HTLV-I are discussed.

Hemophagocytic syndrome as a presenting sign of transformation of smoldering to acute adult T-cell leukemia/lymphoma: efficacy of anti-retroviral and interferon therapy

A 55-year-old Caribbean woman with a 6-year history of smoldering adult T-cell leukemia/lymphoma presented with clinical and biological symptoms of hemophagocytic syndrome. An extensive search for infectious diseases was negative. A lymph node biopsy showing large T-cell lymphoma (CD4-, CD25+) and findings of high LDH count and severe lymphocytosis led to the diagnosis of acute adult T-cell leukemia/lymphoma. Anti-retroviral therapy combining zidovudine, lamivudine, and interferon-alpha was started, resulting in rapid control of both hemophagocytic syndrome and symptoms of acute adult T-cell leukemia/lymphoma. Thus, we propose that adult T-cell leukemia/lymphoma must be added to the spectrum of etiologies of hemophagocytic syndrome.