Protracted Treponema pallidum-induced cutaneous chancres in rabbits infected with human T-cell leukemia virus type I

Myelopathy secondary to human T-lymphotropic virus and Treponema pallidum infection: case report

Introduction

The human T-lymphotropic virus has been associated with human disease, affecting CD4+ T, CD8+ T, and B lymphocytes. It can cause T-cell leukemia/lymphoma and HTLV-associated myelopathy.

Case presentation

A 31-year-old woman was admitted after 2 months of cramps, paraparesis, and fecal/urinary incontinence. She was diagnosed with neurosyphilis according to the cerebrospinal fluid analysis. Despite treatment with crystalline penicillin there was no recovery, and anti-HTLV-1/2 tests were positive; therefore, the diagnosis of HTLV-associated myelopathy was made. The patient rejected glucocorticoid treatment; baclofen and carbamazepine were used to treat spasticity and cramps, respectively. The patient has not had progression.

Discussion

HTLV-associated myelopathy is generated by an exaggerated inflammatory response in the central nervous system with clonal expansion of CD4+ T and CD8+ T lymphocytes. There is not a specific and useful treatment; glucocorticoids can reduce inflammation, but do not improve clinical functional outcomes. There is a high prevalence of syphilis and human T-lymphotropic virus co-infection in tropical countries; however, myelopathy as the first clinical manifestation is unusual. The treatment of neurosyphilis could reduce the inflammation into the central nervous system and could decrease the progression of sequelae. This is the first case of myelopathy secondary to viral and treponemal co-infection confirmed in Colombia.

Defective infection of rabbit peripheral blood monocyte cultures with human immunodeficiency virus type 1

Human immunodeficiency virus type 1 (HIV-1) produces abortive infections of primary cultures of rabbit peripheral blood mononuclear cells (PMBCs). Mitogen activation of rabbit PBMCs or the addition of exogenous cytokines to the cultures does not change the level of release of the early HIV core protein, p24, into the culture medium. The amount of p24 increases steadily and reaches peak levels about 7 days after infection. HIV-1-specific DNA env sequences are also detected in infected PBMCs. However, reverse transcription of RNA of samples from activated infected cultures to cDNA, followed by amplification by the polymerase chain reaction, revealed transcription of gag, but not env, regions, suggesting that HIV-1 infection of rabbit PBMC does not lead to the replication and maturation of complete HIV-1 virions. In addition, neither CPE nor lytic infection was observed in HIV-1-infected rabbit cells and infectivity could not be transferred from rabbit cells infected with HIV for up to 2 weeks to MT-2 or H9 indicator cell lines. In addition, no CPE was seen in long-term cultures of the HTLV-I-transformed rabbit cell line PLT-1441, after inoculation with HIV. It is concluded that primary rabbit PBMCs may be infectable by HIV-1 but are not permissive for production of infectious virus. This conclusion is consistent with the apparent long-term latent infection seen after inoculation of rabbits with HIV-1 or HIV-1-infected cells.