Miniaturized flow cytometry-based BCR-ABL immunoassay in detecting leptomeningeal disease.

Despite central nervous system (CNS) prophylactic programs limit leptomeningeal involvement in acute lymphoblastic leukemia (ALL), it can still occur in a restricted percentage of cases. The exact risk rate remains still unknown, and several factors are associated with an increased probability to develop CNS involvement. Among them, Philadelphia (Ph)-positive genotype seems to play a relevant role. Recently, a flow cytometric assay to detect BCR-ABL protein has been developed, but little is known about its possible employment in leptomeningeal disease. Here, we show the miniaturized application of the original assay for BCR-ABL oncoprotein detection in cerebrospinal fluid (CSF) samples.

Toxoplasmosis encephalitis following severe graft-vs.-host disease after allogeneic hematopoietic stem cell transplantation: 17 yr experience in Fukuoka BMT group.

Toxoplasmosis is a rare but rapidly fatal complication that can occur following hematopoietic stem cell transplantation (HSCT). Over a 17-yr period at our institutions, a definite diagnosis of toxoplasmosis was made in only two of 925 allogeneic HSCT recipients (0.22%) and none of 641 autologous HSCT recipients. These two patients received a conventional conditioning regimen followed by transplantation from an HLA-matched donor; however, they developed severe graft-vs.-host disease, which required intensive immunosuppressive therapy. Despite prophylactic treatment with trimethoprim/sulfamethoxazole, their immunosuppressive state, as indicated by a low CD4(+) cell count, might have resulted in toxoplasmosis encephalitis. Rapid and non-invasive methods such as a polymerase chain reaction (PCR) test of their cerebrospinal fluid for Toxoplasma gondii and magnetic resonance imaging of the brain were useful for providing a definitive diagnosis and prompt therapy in these patients: one patient stabilized and survived after responding to treatment with pyrimethamine/sulfodiazine whereas the other died of bacterial infection. In addition, retrospective PCR analyses of the frozen stored peripheral blood samples disclosed that detection of T. gondii preceded the onset of disease, indicating routine PCR testing of peripheral blood specimens may be an early diagnostic tool. It should be noted that when patients receiving HSCT have an unexplained fever and/or neurological complications, PCR tests should be considered to avoid cerebral lesions and improve the outcome of the patients.

CNS blast crisis of chronic myelogenous leukemia in a patient with a major cytogenetic response in bone marrow associated with low levels of imatinib mesylate and its N-desmethylated metabolite in cerebral spinal fluid.

Imatinib mesylate (STI571) is a very effective treatment option for Ph(+) chronic myeloid leukemia (CML) in chronic phase. Secondary treatment failures have mostly been observed in patients with advanced stages of disease. We report the case of a patient who unexpectedly experienced blast crisis of the central nervous system although having achieved complete cytogenetic remission in the bone marrow. The levels of STI571 and its metabolite N-desmethyl STI were 40-fold lower in the cerebral spine fluid than in plasma. The risk of CNS disease has to be kept in mind when patients with CML in chronic phase who are at an increased risk for blastic transformation are treated with imatinib mesylate.

Isolated central nervous system blast crisis in chronic myeloid leukemia.

Chronic myeloid leukemia is a myeloproliferative disorder characterized by the presence of the Philadelphia chromosome, t(9:22). Extramedullary blast crisis is a rare event. Imatinib mesylate has become the treatment of choice, especially for patients for whom allogenic stem cell transplantation is not an option. Imatinib produces complete cytogenetic responses in excess of 80%. However, the penetration of the drug and its metabolites into the CNS (Central Nervous System) is poor. Hence for patients who are on prolonged imatinib therapy and continue to have complete cytogenetic responses, the central nervous system may become a sanctuary site. We report a patient who had a complete hematologic and cytogenetic response and presented with headache and vomiting. The MRI showed meningeal enhancement and the CSF (Cerebro Spinal Fluid) examination was positive for blasts. He was started on cranial radiotherapy and triple intrathecal chemotherapy. He showed good symptomatic improvement and cleared the blasts in the CSF. At the end of radiation, he was in complete hematological remission but had 50% marrow metaphases positive for Philadelphia chromosome. As he did not have a matched sibling donor, the dose of imatinib was increased to 600 mg daily. He continues to be in complete hematologic remission at the time of this report.

Low concentrations of STI571 in the cerebrospinal fluid: a case report.

We report a 53-year-old man with lymphoid blast crisis of Ph+ chronic myeloid leukaemia who was treated with STI571, a selective inhibitor of the enzymatic activity of BCR-ABL. He responded excellently to STI571 (600 mg/d), obtaining a complete cytogenetic remission after 3 months of therapy. Although remission in the bone marrow was sustained, the patient developed an isolated central nervous system relapse. Subsequent analyses of STI571 concentrations in the cerebrospinal fluid (CSF) revealed 2-log lower CSF levels of STI571 than corresponding plasma levels. These are the first data demonstrating a low penetration of orally administered STI571 into the CSF in humans.

Leukemic cells growth fraction in the central nervous system in blastic phase of chronic myelogenous leukemia.

Clinical and neuropathological investigations were carried out in 6 patients, deceased due to blastic phase of chronic myelogenous leukemia (BPCML). Growth fraction of leukemic cells in peripheral blood, cerebrospinal fluid and in the central nervous system (CNS) was studied, using mitotic index and immunohistochemical staining technique with the monoclonal antibody antiproliferating cell nuclear antigen (anti-PCNA). The results suggest that in BPCML the proliferative activity of leukemic cells is low both in peripheral blood, cerebrospinal fluid, cerebral leukostasis and within the leptomeningeal and intracerebral infiltrates, even in cases with a very high white blood cells count. It can confirm the opinion that in BPCML, accumulation rather than proliferation of leukemic cells plays an important role in the development of the CNS leukemia.

Cleaved L-selectin concentrations in meningeal leukaemia.

Involvement of the central nervous system has important therapeutic implications in acute leukaemia. Because the identification of blast cells in cerebrospinal fluid (CSF) is often difficult, there is a need for sensitive markers of leukaemic infiltration. Since the shed form of L-selectin (sL-selectin) is frequently increased in acute leukaemia (sL-selectin+ leukaemia), we examined whether assay of sL-selectin in CSF could improve our ability to detect such meningeal involvement. CSF sL-selectin was significantly (p < 0.001) higher in 15 patients with sL-selectin+ meningeal leukaemia (median 60 ng/mL, range 34-150) than in 20 patients with acute leukaemia without meningeal involvement (12 ng/mL, 1-39) or 88 control patients (14 ng/mL, 0-37). Serial measurements of sL-selectin in patients with sL-selectin+ leukaemic meningitis showed increased CSF concentrations of the cleaved receptor in 4 patients with therapy-resistant meningeal leukaemia and sustained normal concentrations in 9 patients in remission. Our results suggest that CSF sL-selectin may be a useful marker in the detection of meningeal involvement by blast cells in patients with sL-selectin+ leukaemia.

[Experience with the molecular genetical detection of the chimera gene of the Philadelphia chromosome]. / Philadelphia chromosoma chimera génje molekuláris genetikai kimutatásának tapasztalatai.

Molecular genetical techniques could be developed for detection of the chimera gene of Philadelphia chromosome or that of its gene product, due to the relatively conserved structure of the chimera gene. The authors successfully analysed 123 blood/bone marrow samples from 106 patients using these molecular techniques adapted from the literature. Patients were classified by the first diagnosis, 65 CML, 7 AML, 13 ALL patients were studied. 12 patients had the diagnosis of myeloproliferative syndrome, and 9 patients were after bone marrow transplantation. 57% of the total, and by diagnosis, 74% of CML, 28% of AML, 54% of ALL, and 33% of post-transplant samples have shown the chimera gene structure characteristic for Philadelphia chromosome. All patients of myeloproliferative syndrome were negative. In some cases the authors had the opportunity to study simultaneously the peripheral blood and the bone marrow sample of the same patient and of the same date. The ratio of the positivity of the two samples varied from one to infinite. The authors could follow the effect of interferon in one case, the change of clonality of the leukemic cell line in an other case. They had the opportunity to detect two different abnormal gene structures in the sample of an AML patient.

[The cytological possibilities for the early diagnosis of neuroleukemia]. / Tsitologicheskie vozmozhnosti rannei diagnostiki neiroleikemii.

The authors present the results of analyses of 425 samples of the cerebrospinal fluid from 67 patients with acute leukemia and from 30 ones with chronic myeloleukemia, carried out by the sedimentation method. This method permits concentration of the cells on a small site of the slide, involving the minimal injury to the cells, and thus helps obtain the cellular picture of the liquor, available for morphologic analysis. Detection in the sedimentation preparations with normal parameters of liquor cytosis of the blast cells in patients with acute leukemia and of the entire spectrum of maturing granulocytes with blasts in chronic myeloleukemia patients permits the diagnosis of the preclinical stage of neuroleukemia and thus helps detect the patients, for whom all the measures, included in the neuroleukemia prevention program, are absolutely obligatory and whose cerebrospinal fluid cellular composition should be regularly checked up.

[The cytological and biochemical aspects of studying the cerebrospinal fluid in patients with chronic myeloleukemia]. / Tsitologicheskie i biokhimicheskie aspekty issledovaniia spinnomozgovoi zhidkosti u bol'nykh khronicheskim mieloleikozom.

The investigation of cell composition and different biochemical parameters (ceruloplasmin, lactate dehydrogenase, aldolase, ferritin, beta-2-microglobulin) in cerebrospinal fluid has been performed in 37 patients with chronic myeloid leukemia at different clinicohematological stages. The age of the patients ranged from 16 to 67 years. CNS involvement has been diagnosed in 8 (21.6%) patients by clinical and cytological criteria and in 5 (13.5%) patients on the basis of changes in liquor cytograms and in biochemistry. Morphological substrate of leukemic infiltration may be represented by blast cells and cells of granulocytic line of all stages of differentiation. Direct correlation has been established between ferritin and beta-2-microglobulin levels in liquor and its cytological patterns. This permits a conclusion on possible usage of liquor concentration of beta-2-microglobulin and ferritin measurements as additional tests in the diagnosis of neuroleukemia in chronic myeloid leukemia.