Level of tau protein in children treated for acute lymphoblastic leukemia.

Long-term neuropsychological complications such as attention and concentration disturbances, poor school performance, hyperexcitability, and even leukoencephalopathy have been described in children after chemotherapy for acute lymphoblastic leukemia. Elevation of the cerebrospinal fluid level of tau protein, associated with neuronal axons, is a neurodegenerative marker. The aim of the study was to assess the level of cerebrospinal fluid tau protein in children with acute lymphoblastic leukemia. The study included 26 patients with acute lymphoblastic leukemia and 19 patients with clinical symptoms of cerebrospinal meningitis (reference group). Tau protein levels were determined by enzyme-linked immunosorbent assay. Cerebrospinal fluid total protein level was not elevated in any of the samples. The examination was performed at diagnosis, after induction treatment, during consolidation, and after reinduction, i.e. before maintenance therapy. Neither age nor sex had an effect on tau protein levels in both groups. The mean tau protein value at diagnosis was 244.84 +/- 98.96 pg/mL in the study group (norm 300 pg/mL) and produced no correlation with initial leukocytosis, lactate dehydrogenase activity, or organomegaly at this point. Dynamic analysis revealed a statistically significant increase in tau protein after induction treatment (431.25 +/- 232.50) as compared with its level at diagnosis (244.84 +/- 98.96, P < 0.008) and later during treatment. The levels of tau protein at various points of treatment did not differ statistically significantly between the groups, except for the values obtained after termination of remission induction. The observed metabolic changes in tau protein, which is a known marker of neuronal damage, indicate that some patients are at a greater risk of central nervous system disorders. This finding requires further studies, also in reference to other central nervous system proteins, and confirms the necessity of long-term follow-up of leukemia patients.

Flow cytometry and the study of central nervous disease in patients with acute leukaemia.

Central nervous system (CNS) leukaemia is still a matter of debate and new technologies are required to improve the classic morphological definition. One hundred and sixty-eight cerebrospinal fluid (CSF) samples from 31 patients with acute leukaemia were analysed by flow cytometry and conventional cytology. Concordant positive and negative findings were found in 158 samples but 10 produced discrepant results. Cytology seemed to offer more precise information in one CSF sample and flow cytometric accuracy could be demonstrated in five samples. We conclude that flow cytometry is of great help in confirming CNS leukaemia and eliminating other conditions. Therefore, leukaemic patients can benefit from double cytological and flow cytometric CSF studies.

Identification of interleukin-6 producing fibroblastoid cells in cerebrospinal fluid from patients with leukemic meningitis.

Cytokine producing native cells in cerebrospinal fluid (CSF) have not been identified. So, we investigated the cytokine producing ability of floating cells in CSF from patients with leukemic meningitis. Morphologic study revealed that established cell lines were polygonal or elongated in shape and had an abundant and irregular branched cytoplasm. Immunocytochemical analysis demonstrated positive reactivity with monoclonal anti-fibroblast antibody only. Interleukin-6 (IL-6) was constitutively produced in vitro by these cell lines; both interleukin-1 and lipopolysaccharides significantly increased its synthesis. These findings imply that these fibroblastoid cells are floating in CSF of patients with leukemic meningitis and produce IL-6 in response to various inflammatory stimulations in vivo.

[Clinical significance of soluble interleukin-2 receptor levels in the cerebrospinal fluid in patients with adult T-cell leukemia complicated with meningeal infiltration].

We measured soluble interleukin-2 receptor (sIL-2R) levels in the cerebrospinal fluid (CSF) of patients with hematological malignancies especially, adult T-cell leukemia (ATL) and non-Hodgkin's lymphoma (NHL) with or without meningeal infiltration. CSF levels of sIL-2R were significantly higher in patients with ATL and NHL with meningeal infiltration than in patients with both diseases without meningeal infiltration. The sIL-2R levels in CSF were elevated in 4/4 ATL patients (100%) and 3/13 NHL patients (23%) with meningeal infiltration. CSF levels of sIL-2R from ATL patients with meningeal infiltration had a tendency to elevate in correlation with numbers of mononuclear cells and lactic dehydrogenase (LDH) in CSF. However, these had no correlation with serum levels of sIL-2R. Therefore, sIL-2 levels in CSF may be useful in the diagnosis of meningeal infiltration in patients with ATL, are probably specific markers for meningeal infiltration of ATL.

Significance of elevated levels of soluble factors in the cerebrospinal fluid in patients with adult T-cell leukemia.

Although it has been recognized previously that several markers are present in the cerebrospinal fluid (CSF), their clinical usefulness of these markers in the diagnosis of malignant lymphoma infiltrating to the CNS has not yet been established. In order to determine their diagnostic usefulness as markers of meningeal infiltration by lymphoma cells in patients with adult T-cell leukemia (ATL), we measured some soluble factors in the CSF of patients with ATL and non-ATL patients. Soluble CD4 (sCD4) was highly elevated in all patients with ATL and meningeal infiltration. The CSF level of the soluble interleukin-2 receptor (sIL-2R; sCD25) was markedly elevated in 13 (72.2%) of 18 patients with ATL and meningeal infiltration. Levels of sCD4 and sCD25 in the CSF of patients with ATL and meningeal infiltration were significantly higher than in non-ATL patients (p < .01 and p < .001, respectively). These findings indicate that levels of sCD4 and sCD25 in the CSF are probably associated with meningeal infiltration by leukemia cells expressing CD4 and CD25 on surface membranes. CSF levels of sCD4 in 14 (60.9%) of 23 ATL patients and sCD25 in 13 (72.2%) of 18 ATL patients without meningeal infiltration were moderately elevated. These findings suggest that a small number of leukemic cells which were not detected by conventional CSF examination may have infiltrated the meninges in these patients. Sequential measurements of sCD4 and sCD25 in CSF obtained from patients with meningeal infiltration by leukemic cells showed that sCD4 and sCD25 levels reflected the activity of leukemic meningitis and correlated with the number of cells in CSF. However, the levels of sCD4 in CSF did not fall below the limit of detection even when the number of cells in CSF became normal. It is thought that the level of sCD4 in CSF is a more sensitive marker for detecting the infiltration of leukemic cells in CSF than the number of cells present in the CSF considering the clinical course of two patients with acute type ATL. Therefore, ATL patients with meningeal infiltration should receive treatments until sCD4 levels become normal and not just until the number of cells become normal. Our results also suggest that measurement of CSF levels of sCD4 and sCD25 is useful for the differential diagnosis of aseptic meningitis and meningeal infiltration by leukemic cells in patients with smoldering ATL. We conclude that measurement of soluble factors in CSF plays an important role in diagnosis, prophylaxis and treatment of meningitis in patients with ATL.

Elevated levels of soluble factors in the cerebrospinal fluid in patients with adult T-cell leukaemia complicated with meningeal infiltration.

We measured some soluble factors in the cerebrospinal fluid (CSF) of patients with adult T-cell leukaemia (ATL) complicated with meningeal infiltration. Interleukin-4 (IL-4) was not detectable in the CSF of all cases with meningeal infiltration. Interleukin-6 (IL-6) was detected in a few patients with ATL. Measurement of IL-4 and IL-6 in CSF had no diagnostic value for meningeal infiltration of ATL cells. Soluble CD4 (sCD4) was highly elevated in all ATL patients with meningeal infiltration. Soluble interleukin-2 receptor (sIL-2R; sCD25) in CSF was markedly elevated in 13/18 ATL patients (72.2%) with meningeal infiltration. Levels of sCD4 and sCD25 in the CSF of ATL patients with central nervous system (CNS) symptoms were significantly higher than those of non-ATL patients with CNS symptoms. These observations indicate that sCD4 and sCD25 in the CSF are probably associated with meningeal infiltration of leukaemia cells that expressed CD4 and CD25 on the surface membrane and new markers for the meningeal infiltration of ATL cells.

Elevated soluble CD4 levels in the cerebrospinal fluid in patients with adult T-cell leukemia.

Levels of the soluble form of the leukocyte surface antigen CD4 (sCD4) were measured by enzyme linked immunosorbent assay (ELISA) in the cerebrospinal fluid (CSF) of patients with adult T-cell leukemia (ATL) and other malignant and non-malignant diseases. All patients with ATL and meningeal infiltration had markedly elevated levels of sCD4 in the CSF (53.7 +/- 34.9 U/ml). ATL patients without CSF pleocytosis often had elevated levels of sCD4 (15.1 +/- 9.2 U/ml). Non-ATL patients with CSF pleocytosis had elevated levels of sCD4 (23.3 +/- 12.2 U/ml) and those without CSF pleocytosis also showed elevation of sCD4 levels (16.8 +/- 9.3 U/ml). However, the mean levels of sCD4 in CSF from these patients were significantly lower than ATL patients with meningeal infiltration. Soluble CD4 in the CSF from healthy volunteers were below the detectable limit. We conclude that meningeal infiltration of CD4(+) ATL cells is strongly associated with elevated sCD4 levels in CSF, and some part of sCD4 in CSF may be originated from the native cells in the CNS as a response of inflammatory stimulations. Therefore, measurement of sCD4 may be useful in the diagnosis of meningeal infiltration and/or meningeal irritation in patients with ATL.