The clinical, laboratory and epidemiological characteristics of 38 adult Jamaican patients with polymyositis were evaluated. Twenty-four patients (63%) were human T-lymphotropic virus 1 (HTLV-1) seropositive and 14 patients (37%) were HTLV-1 seronegative. Polymyositis runs a more protracted course in seropositive patients who had more frequent hospital admissions and a significantly longer duration of symptoms prior to presentation. Joint swelling, chest pain and dyspnoea were more frequent complaints among the seronegative patients. There was no significant difference between the two serological groups in muscle enzyme levels, antinuclear antibody positivity or frequency of Jo-1 antibodies. HTLV-1 infection may define a subgroup of polymyositis patients with a more insidious presentation and poorer response to corticosteroid therapy.

This paper reports a case of a Jamaican young woman who experienced flaccid quadriparesis and bulbar weakness over a three-week period after a gastrointestinal illness. Nerve conduction studies confirmed an axonal type neuropathy consistent with the acute motor-sensory axonal neuropathy variant of the Guillain-Barré syndrome. Recovery, although evident, was slow and was augmented after a course of intravenous immunoglobulin. The patient was discharged from hospital after three months but was re-admitted one week later and eventually succumbed to complications of the illness. This case serves as a reminder that Guillain-Barré syndrome is now the most common cause of acute flaccid paralysis and should be considered early in all patients presenting with flaccid quadriparesis.

Background Next to Sub-Saharan Africa, the Caribbean has the second highest prevalence of human immunodeficiency virus type 1 (HIV-1) infection; and human T-cell lymphotropic virus type 1 (HTLV-1), another human retrovirus, is also endemic. Fewer than five percent of persons with HTLV-1, predominantly transmitted through breast feeding, progress to any of the myriad associated diseases, including adult T-cell leukemia, HTLV-1 associated myelopathy/Tropical Spastic Paraparesis (HAM/TSP), or polymyositis. HTLV-1, through its oncoprotein-like transactivating (Tax) protein, results in aberrant proliferation of CD4 cells through interaction with cell cycle regulators, and activation of nuclear factor kappa B and the interleukin-2 pathway. Elevated CD4 counts, often above normal range, observed in patients with HTLV-1/HIV-1 co-infection, may be spurious, posing a challenge for laboratory monitoring of lymphoproliferative disorders or HIV-1 progression. Methods We compared CD4 counts, HIV-1 viral load, and clinical parameters in a cohort of patients co-infected with HTLV-1 and HIV-1 (syphilis, hepatitis B and C non-reactive), with controls with HIV-1 infection only matched for age, sex, and duration of antiretroviral therapy, as well as donors without HTLV-1 or HIV-1 infection. We used flow cytometry to characterize CD4 and CD8 naïve and memory T-cell subsets, expression of T-cell survival and homeostatic cytokine interleukin-7 alpha receptor (CD127), and examined the role of co-inhibitory programmed death-1 in HTLV-1 infected (intracellular HTLV-1 Tax protein-expressing) and HIV-1 infected (intracellular HIV-1 Gag protein-expressing) CD4 cells in immune evasion. Additionally, we assessed the effects of exogenous interleukin-7 (IL-7) and programmed death-1 pathway blockade on the function of responding CD8 cytotoxic T-lymphocyte (CTL) subsets ex vivo. Results All patients with HTLV-1 and HIV-1 co-infection (n = 5) were female and of median age 42 years (range, 22 to 49 years), with normal or above normal CD4 counts. Four of five patients with HTLV-1/HIV-1 co-infection were WHO Stage 4 HIV/AIDS at diagnosis (e.g., oesophageal candidiasis, HIV nephropathy). Median duration since diagnosis with HIV-1 infection was six years (range, 1 to 18 years), and unexpectedly high CD4 count was the reason for HTLV-1/2 testing in all cases. Nadir CD4 count among patients with HTLV-1/HIV-1 co-infection was significantly higher than controls with HIV-1 infection only (n = 12) matched for age, sex, and duration of antiretroviral therapy (median 684, range 467 to 1474; and median 36, range, 8 to 352 cells per microliter, respectively; p = 0.007, Mann-Whitney U test). Flow cytometric analyses of CD8 and CD4 T-cell memory subsets revealed more profound loss of CD127 in the CD8 compared to the CD4 compartment; and CD8(+) effector memory T-cells showed the most significant downregulation of CD127 when patients with HTLV-1/HIV-1 co-infection were compared with seronegative donors (40.3±17.0%, n =5; and 73.1±7.48%, n = 10, respectively; p = 0.032, Mann-Whitney U). In ex vivo experiments in the context of peripheral blood mononuclear cells, preliminary data suggest that patients with HTLV-1/HIV-1 co-infection have impaired CD8(+) CTL function in response to HLA-restricted HTLV-1 Tax11-19 and cytomegalovirus (CMV) pp65 peptide stimulation. Further, we sought to describe expression of co-inhibitory marker programmed death-1 ligand (PDL1) on intracellular HTLV-1 Tax protein- as well as intracellular HIV-1 Gag protein-expressing CD4 cells. Blockade of PDL1 resulted in partial recovery of CTL function in patients with HTLV-1/HIV co-infection, and enhanced killing of target cells infected with either HTLV-1 or HIV-1. Conclusions Patients with HTLV-1/HIV-1 co-infection show profound CTL exhaustion; and CD4 cells, although within or above normal CD4 count range, show aberrant naïve and memory T-cell distribution and possible immune evasion by upregulation of the programmed death-1 pathway, blockade of which showed a tendency towards enhanced virus-specific CTL function and killing of target cells infected with HTLV-1 or HIV-1. Disclosures: No relevant conflicts of interest to declare.