Poor response to prednisolone of idiopathic thrombocytopenia with human T-lymphotropic virus type I infection

Human T-lymphotropic virus type I infection and idiopathic thrombocytopnic purpura

Human T-lymphotropic virus type I (HTLV-I) is the causative agent in adult T-cell leukemia and HTLV-I associated myelopathy. Some other diseases such as uveitis, chronic thyroiditis, Sjögren syndrome, arthritis, acute myeloid leukemia and myelodysplastic syndrome may be also associated with HTLV-I. Several case reports have suggested the possible combination of idiopathic thrombocytopenic purpura (ITP) and HTLV-I infection. In these studies and from our current report, we found 17 patients (22.1%) with HTLV-I infection among 77 ITP patients. The prevalence of HTLV-I infection among ITP patients was higher than that of healthy volunteers (5 approximately 10%). The ITP patients with HTLV-I infection were older than the patients without HTLV-I infection, and the ITP patients with HTLV-I infection had poor response to prednisolone therapy. Among 17 ITP patients with HTLV-I infection, 9 patients received prednisolone therapy. Although most patients had transient increase of platelet counts, only two of them had partial responses (PR) at the last observation date. Five patients underwent splenectomy, and four of them had complete responses (CR) and the remaining patient had a (PR). Four patients received eradication of Helicobactor pylori (H. pylori) infection, and all patients had CRs. Therefore, the ITP patients with HTLV-I infection should receive eradication therapy in the case of H. pylori infection as the first step of therapy and the splenectomy should be considered, if there is no response to conventional therapy. Human immunodeficiency virus (HIV) causes thrombocytopenia in 10% of patients with active HIV disease. The etiologies of HIV thrombocytopenia are considered as follows, the escalated destruction of platelets by the immune system, damage to megakaryocytes by HIV infection and the inhibition of thrombopoiesis by some anti-viral drugs. In the case of ITP patients with HTLV-I infection, the main etiology may be the increased destruction of platelets by immune system. The proviral load and the integration pattern of HTLV-I should be examined to clarify the stage of HTLV-I infection. The possibility of infection of the megakaryocytes by HTLV-I should be also examined for etiological approach.

High prevalence of human T-lymphotropic virus type I carriers among patients with myelodysplastic syndrome refractory anemia with excess of blasts (RAEB), RAEB in transformation and acute promyelocytic leukemia

We examined human T-lymphotropic virus type I (HTLV-I) infection among patients with myelodysplastic syndrome (MDS), refractory anemia with excess of blasts (RAEB)/RAEB in transformation (RAEBt) and acute myelogenous leukemia (AML). The study population consisted of 151 patients: 46 with MDS RAEB/RAEBt and 105 with AML (M1, n = 15; M2, n = 39; M3, n = 18; M4, n = 19; M5, n = 9; M6, n = 3; M7, n = 2). As a reference, we examined 92 patients with refractory anemia (RA) and 405 patients with cardiovascular diseases (CVD). Thirteen patients with RAEB/RAEBt (28.3%), 11 with AML (11.6%), 27 with RA (29.3%), and 45 with CVD (11.0%) were positive for HTLV-I. Seven AML patients with HTLV-I infection had M3 acute promyelocytic leukemia (APL). The prevalences of HTLV-I infection among patients with RAEB/RAEBt (P < 0.001), APL (P = 0.001), and RA (P < 0.001) were significantly higher than that in patients with CVD. The prevalences of HTLV-I infection were still significantly higher in patients with RAEB/RAEBt (P = 0.007), APL (P = 0.017) and RA (P < 0.001) than in those with CVD matched by sex and age. Platelet counts and survival times of RAEB/RAEBt patients with infection were significantly lower than those of patients without infection.

Spontaneous cell proliferation is associated with poor sensitivity to glucocorticoids in patients infected with HTLV

BACKGROUND

Human T-cell lymphotropic viruses (HTLV)-I/II have a special tropism for infecting T cells and inducing spontaneous lymphocyte proliferation. Leukaemia and neurological manifestations are associated with HTLV-I/II infections, and treatment is usually based on anti-inflammatory drugs including glucocorticoids. Although steroid resistance has been reported, it is unknown whether this condition is related to the infection itself or to the treatment.

OBJECTIVE

We investigated whether spontaneous cell proliferation is associated with T-cell sensitivity to glucocorticoids.

MATERIALS AND METHODS

Twenty-eight HTLV-I/II patients and 11 healthy age-matched controls took part in this study. Lymphocytes were isolated and cultured in vitro to measure spontaneous and mitogen-induced proliferation as well as cellular sensitivity to dexamethasone.

RESULTS

Patients with HTLV-I/II infection showed similar stimulated and unstimulated T-cell proliferation as well as comparable sensitivity to dexamethasone in vitro. There were no group differences in the frequency of glucocorticoid responders versus non-responders. However, T cells of patients with spontaneous proliferation were unresponsive to mitogenic stimulation and were remarkably more resistant to dexamethasone than cells of patients with normal proliferation.

CONCLUSION

These data suggest that the poor clinical response to steroids may be associated with spontaneous cell proliferation during HTLV infection.

Spleen-dependent turnover of CD11b peripheral blood B lymphocytes in bovine leukemia virus-infected sheep

Lymphocyte homeostasis is determined by a critical balance between cell proliferation and death, an equilibrium which is deregulated in bovine leukemia virus (BLV)-infected sheep. We have previously shown that an excess of proliferation occurs in lymphoid tissues and that the peripheral blood population is prone to increased cell death. To further understand the mechanisms involved, we evaluated the physiological role of the spleen in this accelerated turnover. To this end, B lymphocytes were labeled in vivo using a fluorescent marker (carboxyfluorescein diacetate succinimidyl ester), and the cell kinetic parameters (proliferation and death rates) of animals before and after splenectomy were compared. We show that the enhanced cell death observed in BLV-infected sheep is abrogated after splenectomy, revealing a key role of the spleen in B-lymphocyte dynamics.

Natural course of voiding function in patients with human T-cell lymphotrophic virus type 1-associated myelopathy

OBJECTIVES

Patients with human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) frequently experience voiding dysfunction. In patients with HAM/TSP, the major symptoms are gait disturbance and voiding dysfunction. However, the detailed natural course of voiding function and the management of their urination has not previously been investigated. We examined the correlation between voiding function and clinical features and evaluated the management of urination, in the patients with HAM/TSP.

PATIENTS AND METHODS

The voiding function of 47 patients (7 males, 40 females, aged 29-89 years, mean: 60.9 years) with HAM/TSP was analyzed retrospectively. All HAM/TSP patients are positive for HTLV-1. Patients were referred to a neurologist for analysis of bladder function. In the present study, we analyzed their clinical details, age at disease onset, voiding function and alterations in the management of their urination. Furthermore, we investigated the relationship between urological management and the clinical features of HAM/TSP.

RESULTS

Of the 47 patients, 20 (42.5%) were able to void with or without drug therapy. Thirty-four (72.3%) experienced clean intermittent self-catheterization (CIC), with 25 of these 34 continuing CIC, 7 changing to voiding and 2 changing to management with the Foley catheter. No relationship was noted between disruption of voiding function and either age or gender. However, significant inverse correlation was observed between the age at disease onset and the time to CIC (r=-0.77, P=0.00001).

CONCLUSIONS

These data suggest that the younger a patients is at HAM/TSP onset, the longer voiding function will be maintained.