Human T-cell lymphotropic virus type I (HTLV-I) proviral DNA viral load among asymptomatic patients and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis.

To evaluate the human T-cell lymphotropic virus type I (HTLV-I) proviral DNA load among asymptomatic HTLV-I-infected carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), real time PCR using TaqMan probes for the pol gene was performed in two million peripheral blood mononuclear cells (PBMC). The albumin gene was the internal genomic control and MT2 cells were used as positive control. The results are reported as copies/10,000 PBMC, and the detection limit was 10 copies. A total of 89 subjects (44 HAM/TSP and 45 healthy HTLV-I-infected carriers) followed up at the Institute of Infectious Diseases "Emilio Ribas" and in the Neurology Division of Hospital of Clínicas were studied. The asymptomatic HTLV-I-infected carriers had a median number of 271 copies (ranging from 5 to 4756 copies), whereas the HAM/TSP cases presented a median of 679 copies (5-5360 copies) in 10,000 PBMC. Thus, HAM/TSP patients presented a significantly higher HTLV-I proviral DNA load than healthy HTLV-I carriers (P = 0.005, one-way Mann-Whitney test). As observed in other persistent infections, proviral DNA load quantification may be an important tool for monotoring HTLV-I-infected subjects. However, long-term follow-up is necessary to validate this assay in the clinical setting.

Human T-cell lymphotropic virus type I (HTLV-I) proviral DNA viral load among asymptomatic patients and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis

To evaluate the human T-cell lymphotropic virus type I (HTLV-I) proviral DNA load among asymptomatic HTLV-I-infected carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), real time PCR using TaqMan probes for the pol gene was performed in two million peripheral blood mononuclear cells (PBMC). The albumin gene was the internal genomic control and MT2 cells were used as positive control. The results are reported as copies/10,000 PBMC, and the detection limit was 10 copies. A total of 89 subjects (44 HAM/TSP and 45 healthy HTLV-I-infected carriers) followed up at the Institute of Infectious Diseases "Emilio Ribas" and in the Neurology Division of Hospital of Clínicas were studied. The asymptomatic HTLV-I-infected carriers had a median number of 271 copies (ranging from 5 to 4756 copies), whereas the HAM/TSP cases presented a median of 679 copies (5-5360 copies) in 10,000 PBMC. Thus, HAM/TSP patients presented a significantly higher HTLV-I proviral DNA load than healthy HTLV-I carriers (P = 0.005, one-way Mann-Whitney test). As observed in other persistent infections, proviral DNA load quantification may be an important tool for monotoring HTLV-I-infected subjects. However, long-term follow-up is necessary to validate this assay in the clinical setting.

Histopathological and immunohistochemical assessment of acquired ichthyosis in patients with human T-cell lymphotropic virus type I-associated myelopathy.

BACKGROUND: Patients with human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy frequently display cutaneous alterations such as acquired ichthyosis. OBJECTIVES: Elucidation of the pattern of acquired ichthyosis in HTLV-I-associated myelopathy. METHODS: Skin fragments from 10 patients with HTLV-I-associated myelopathy presenting with acquired ichthyosis were assessed by histopathological and immunohistochemical tests. We used anticytokeratin antibodies related to normal keratinization (K1/K10), and others related to cutaneous conditions such as activation, migration and hyperproliferation of keratinocytes (K6/K16), and involucrin, a precursor protein in the formation of the protein envelope in keratinocytes. For quantification of the proliferating basal and parabasal cells the anti-Ki-67 antibody was employed. RESULTS: On light microscopy, all skin specimens displayed orthokeratotic hyperkeratosis and hypogranulosis. Three of them presented focal parakeratosis. A slight to moderate perivascular infiltrate of mononuclear lymphocytes was observed in seven cases, three of which showed discrete spongiosis with epidermotropism of lymphocytes. All fragments displayed coexpression of K1, K10 and K16 in the suprabasal layers. Expression of involucrin was also observed in all cases, in the upper spinous and granular layers. Focal expression of K6 was observed in three cases, under a parakeratotic area. The mean number of Ki-67+ basal and parabasal cells was 3.5 cells per mm, similar to that in control skin. CONCLUSIONS: In acquired ichthyosis related to HTLV-I-associated myelopathy, histopathology revealed orthokeratotic hyperkeratosis and a perivascular inflammatory infiltrate of mononuclear lymphocytes, with areas of parakeratosis and foci of epidermotropism in rare cases. The expression profiles of K1, K10 and involucrin were similar to those in normal skin. The diffuse coexpression of K16 with K1 and K10 throughout the analysed epidermis, as well as the occurrence of restricted areas of parakeratosis expressing K6, indicate the presence of keratinocyte activation with induction of the alternative keratinization pathway, probably dependent on the cytokines liberated by the mononuclear cells of the dermal inflammatory infiltrate infected with HTLV-I. The absence of acanthosis and of increased cellular kinetics, as shown by the low rate of Ki-67 antigen expression, allow the inference that the pattern of acquired ichthyosis related to HTLV-I-associated myelopathy may be retentional. The observation of foci of parakeratosis expressing K6 in three specimens suggests that, at least in certain areas and in some cases, interference with epidermal differentiation and maturation occurs.

Pontine tegmentum hematoma. Report of a case with pure hemiplegia.

The authors report the case of a 50 year-old hypertensive male patient with a pontine hematoma. The clinical presentation was characterized by pure pyramidal deficit signs (no other signs or symptoms were present). A pure hemiplegia syndrome, although common in supratentorial lesions, is considered to be a rare event in pontine vascular lesions. The pathophysiologic mechanisms of these neurological findings are unclear. The exclusive involvement of the pyramidal tract in this case is likely due to a variation in the vascular anatomy of the pons but, in some cases, a vascular malformation may be the cause.