[Serum deoxythymidine kinase in adult T-cell leukemia and its related disorders]

Using Prolifigen TK kit "Daiichi", the serum TK level were determined in patients with adult T-cell leukemia (ATL) and its related disorders. The mean level of serum TK at diagnosis was 279.9 U/l in acute type ATL, 27.8 U/l in chronic type ATL, 59.0 U/l in lymphoma type ATL, 3.1 U/l in pre-ATL and 2.4 U/l in HTLV-I carriers. In these patients, six other kinds of tumor markers such as lactic dehydrogenase, beta 2-microglobulin, immunosuppressive acidic protein, ferritin, tissue polypeptide antigen and carcinoembryonic antigen were also examined. Among the seven tumor markers, TK level showed the most significant difference among clinical subtypes of ATL. This indicates that the TK level is one of the promising parameters indicative of aggressiveness of ATL cells.

Cytogenetic studies of human T-cell leukemia virus type I carriers. A family study

Recently, the chromosome 14q11 anomaly has been reported to be specific to adult T-cell leukemia (ATL), and this anomaly has also been confirmed in the preleukemic state of adult T-cell leukemia (pre-ATL) patients. Because the cytogenetic abnormality at the stage of human T-cell leukemia virus type I (HTLV-I) carrier remains uncertain, we performed cytogenetic studies of lymphocytes stimulated with phytohemagglutinin in three HTLV-I carriers and three non-HTLV-I carriers in an ATL family. As a result, in three HTLV-I carriers, four of 311 cells examined (1.3%) had chromosome 14q11 anomaly. However, in three non-HTLV-I carriers, none of 260 cells examined had chromosome 14q11 anomaly. These results suggest that chromosome 14q11 anomaly is already present at the stage of HTLV-I carrier and seems to be an important cytogenetic clue to the pathogenesis of ATL.

Rearrangements in the human T-cell-receptor alpha-chain locus in patients with adult T-cell leukemia carrying translocations involving chromosome 14q11

We describe 5 cases of adult T-cell leukemia (ATL) carrying translocations at chromosome 14q11, where the genes for alpha- and delta-chains of the T-cell receptor (TCR alpha/delta) reside (Croce et al., 1985; Isobe et al., 1988). Since the TCR alpha/delta locus is the region where several types of chromosome translocations occur in T-cell tumors, rearrangements of the TCR alpha/delta locus in those ATL cases were studied as a first step to characterize these translocations at the molecular level. For this purpose we have generated an extensive series of probes to define the specificity and the diversity of rearrangement occurring at the widely spanned J alpha-C alpha locus and the complex D delta-J delta-C delta-V delta 2 locus. Using a set of probes, we have found the deletion of the TCR delta locus in all ATL cases, and at least 2 rearrangements in the J delta locus in each case of ATL. It is possible that translocations in the TCR alpha locus may be involved in ATL.

Survey of anti-human T-cell leukemia virus type I antibody in family members of patients with adult T-cell leukemia

To evaluate the intrafamilial clustering of HTLV-I, we examined the sera or plasma of 296 healthy family members of patients with adult T-cell leukemia (ATL) for anti-HTLV-I antibodies. Of 296 subjects, 132 (44.6%) had anti-HTLV-I antibodies. Fifty-nine (41.0%) out of 144 males and 73 (48.0%) out of 152 females were seropositive. The positive rates of antibody to HTLV-I increased with age, especially between the 30-39 and the 40-49 age groups. Five out of 6 fathers, 3 out of 4 mothers, 31 (60.8%) out of 51 spouses, 40 (63.5%) out of 63 siblings and 46 (33.8%) out of 136 children of patients with ATL had anti-HTLV-I antibodies. Of 74 children with an ATL father, 14 (18.9%) were seropositive, while 32 (51.6%) out of 63 children with an ATL mother were seropositive. This difference was statistically significant (P less than 0.001). Of those children with an ATL father, 12 (26.1%) out of 46 whose mothers were HTLV-I carriers had antibodies to HTLV-I. In contrast, none of the 13 children whose mothers were not carriers were seropositive. These results supported the hypothesis that the mother-to-child transmission is one of the most important modes of HTLV-I transmission. In wives of male patients with ATL, the positive rate of antibody to HTLV-I was 65.6% (21/32), and in husbands of female patients, it was 52.6% (10/19). The high positive rate of antibody to HTLV-I not only in wives of male patients but also in husbands of female patients suggests that either HTLV-I is more frequently transmitted from wives to their husbands than we had originally expected, or that ATL may develop even in wives who acquire HTLV-I from their husbands after marriage.

[Donath-Landsteiner antibody of the IgM class with anti-I specificity and possible efficacy of azathioprine therapy in paroxysmal cold hemoglobinuria: a case report]

In October 1988, a 72-year-old man was admitted to Nagasaki Prefectural Shimabara Onsen Hospital because of hemoglobinuria on exposure to cold. On admission, the laboratory data were Hb 9.1 g/dl, LDH 2,337 U/L, and haptoglobin less than 6 mg/dl. The Donath-Landsteiner (DL) test was positive and serological tests for syphilis were negative. Anti-Coxsackie virus type A9 antibody titer was elevated. Accordingly, he was diagnosed as having paroxysmal cold hemoglobinuria (PCH) associated with viral infection. The DL antibody proved to be of the IgM class having anti-I specificity. The patient was treated unsuccessfully with prednisolone, but hemolysis was improved after azathioprine (AZP) therapy. PCH patients with DL antibody of the IgM class exhibiting anti-I specificity are very rare and only two patients including the present case have been reported in Japan. There has been no report on the efficacy of AZP in PCH, but our study suggests that AZP may have a potential therapeutic effect in some PCH patients.

[A Japanese family with hereditary HbH disease--a case report and its gene analysis]

Hereditary HbH disease was found in a Japanese family. The propositus showed hypochromic microcytic anemia and chronic hemolysis. HbH inclusion bodies were detected in red cells, and an abnormal band corresponding HbH was found in an isoelectric focusing of the hemolysate. Gene analysis of the propositus revealed double heterozygosity for alpha + and alpha zero thalassemias. Four of six his siblings shared the alpha zero thalassemia and one the alpha + thalassemia. Another one was normal. The alpha + thalassemia was of 3.7 kb-deletion type and alpha zero was close to Southeast Asian type. This is the fourth Japanese family with hereditary HbH disease.

16;21 translocation in acute nonlymphocytic leukemia with abnormal eosinophils: a unique subtype

Two patients with acute nonlymphocytic leukemia (ANLL) and t(16;21)(p11;q22) were studied. The patients exhibited such clinical and hematological pictures, characterized by M2 and M4 with eosinophilia (FAB classification), as relatively matured leukemic cells, low neutrophil alkaline phosphatase activity, abnormal eosinophils and a high count of monocytic cells in the bone marrow. The prognosis was poor in both patients. From these data, the chromosomal abnormality of t(16;21)(p11;q22) seems to be specifically associated with a unique subtype of ANLL.

Serum Gc, Hp and alpha 2HS phenotypes in human T-lymphotropic leukemia virus type I infection

The serum Gc, Hp and alpha 2HS phenotypes were examined in 64 subjects known to have the human T-lymphotropic leukemia virus type I (HTLV-I) infection and in 60 uninfected subjects. There were no significant differences in the distributions of Gc, Hp and alpha 2HS phenotype and allele frequencies between any grouping of HTLV-I-infected subjects and the controls. No association between the Gc, Hp and alpha 2HS genotypes and susceptibility to adult T-cell leukemia was found.

Antibodies against p40tax gene product of human T-lymphotropic virus type-I (HTLV-I) under various conditions of HTLV-I infection

We investigated antibodies against pX gene product, p40tax, by ELISA using recombinant p40tax protein in HTLV-I seropositive carriers as well as patients with adult T cell leukemia (ATL) and HTLV-I-associated myelopathy (HAM). Seventy (49.0%) out of 143 HTLV-I healthy carriers were found to be positive for antibody against p40tax antigen and the follow-up samples at two-year intervals revealed constant reactivity by ELISA in each carrier. The onset of antibody production was delayed 4 to 12 weeks as compared with anti-HTLV-I in primary infection cases. The anti-p40tax-positive rate (90%) in HAM patients was significantly higher than that of healthy carriers, acute and chronic ATL patients and their family members. Furthermore, HAM patients and a few healthy carriers showed high reactivities by ELISA. Children from mothers with anti-p40tax showed a higher anti-HTLV-I-positive rate than that of children from mothers without anti-p40tax (54.5% versus 12.5%). Two men without anti-p40tax and one female with low anti-p40tax developed ATL during follow-up studies. These results suggest that HTLV-I carriers could be divided into 2 or 3 sub-populations according to antibody response to p40tax. A smaller population with anti-p40tax, especially a high antibody reactivity, could have a high risk of developing HAM and of transmission from mother to child. In addition, ATL may occur in a population with low or absent anti-p40tax.

[Cytogenetic studies of healthy HTLV-I carriers (Report 1): Cytogenetic studies of an ATL family]

The chromosome 14q11 anomaly has been reported to be specific to adult T-cell leukemia (ATL) and this anomaly has also been confirmed in preleukemic state of ATL (pre-ATL) patients though the frequency is low. In an attempt to clarify if the same chromosome aberrations could be found also at the stage of HTLV-I carrier and if there is any cytogenetic difference from non-HTLV-I carriers, a cytogenetic study of lymphocytes stimulated with phytohemagglutinin in three HTLV-I healthy carriers and three non-HTLV-I carriers in an ATL family was performed. The results were as follows. 1. In three HTLV-I carriers, 7 of 311 cells examined (2.3%) showed chromosome aberrations, and 4 cells (1.3%) had 14q11 anomaly. 2. In three non-HTLV-I carriers, 4 of 260 cells examined (1.5%) showed chromosome aberrations, whereas no cells had 14q11 anomaly. These findings suggest that 14q11 anomaly is already present at the stage of HTLV-I carrier and seems to be an important cytogenetic clue to the pathogenesis of ATL.

[Study on pathophysiology of the myelodysplastic syndromes (MDS)--pattern of dysmegakaryopoiesis related to leukemic transformation]

A series of 116 patients with MDS consisted of 74 cases of RA, 10 cases of RARS, 14 cases of RAEB, 9 cases of RAEB-T and 9 cases of CMML, were studied on the quantity and morphological abnormalities of megakaryocytes in relation to over all survival and leukemic change. The amount of megakaryocytes was graded into four groups; marked hypoplasia (O), moderate hypoplasia (L), normoplasia (N) and hyperplasia (H), RA cases showed heterogeneous pattern; containing 14 cases (18.9%) of group (O), 18 cases (24.3%) of group (L), 31 cases (41.9%) of group (N) and 11 cases (14.9%) of group (H). RARS, RAEB, RAEB-T and CMML cases were classified into group (N) or group (H). The heterogeneous pattern of RA did not relate to leukemic change, but over all survival tended to be shorter in group (N) cases. A significant number of young female cases of RA were involved in group (O). Morphological abnormalities of MDS megakaryocytes were classified into five types; I, mononuclear micromegakaryocytes, II, binuclear micromegakaryocytes, III, mononuclear small megakaryocytes, IV, multiseparated-nuclear megakaryocytes and V, megakaryocytes with bizzare nuclei. RAEB and RAEB-T cases uniformly showed marked dysmegakaryopoiesis ranging from type I to V. whereas RA, RARS and CMML cases showed mild dysmegakaryopoiesis. Only five cases (6.4%) of RA cases had type I micromegakaryocytes. Eight RA cases with type I on diagnosis or obtaining it during the clinical course tended to develop acute myeloid leukemia (5 cases) or to transform to RAEB sooner or later. In two cases of RAEB in which hematological improvement was obtained with low dose cytosine arabinoside regimen, disappearance of type I micromegakaryocytes was noted. A female case with 5q-anomaly surviving more than 10 years showed marked megakaryocyte hyperplasia and almost exclusively type III and IV megakaryocytes. These findings indicated that pattern of dysmegakaryopoiesis, especially appearance of type I, was closely related to leukemic change in MDS. Thus quantitative and qualitative evaluations of MDS megakaryocytopoiesis seemed important to understand the further heterogeneity of pathophysiology in MDS subtypes.

CML-T1: a cell line derived from T-lymphocyte acute phase of chronic myelogenous leukemia

Most data suggest that malignant transformation in chronic myelogenous leukemia (CML) occurs in hematopoietic stem cell that is the progenitor of myelopoiesis and of B but not T lymphopoiesis. We established a T-lymphoid cell line (CML-T1) from a person with Ph-chromosome-negative CML in acute phase. Evidence of its T-lymphocyte origin includes the pattern cytochemical reactivity, reactivity with anti-T-cell monoclonal antibodies (MoAbs), and rearrangement of the beta-T-cell receptor (TCRB) gene. CML-T1 cells have features of type IV thymocytes. Cytogenetic analyses indicate a 47,XX, del(11), t(6;7)(q23;q24), +mar karyotype. CML-T1 cells exhibit molecular changes typical of CML, including translocation of the ABL protooncogene from chromosome 9 to 22, rearrangement of the BCR gene, and transcription of a chimeric BCR-ABL messenger RNA (mRNA). The ABL insertion on chromosome 22 appears interstitial, similar to other cases of Ph-chromosome-negative CML. These data clearly indicate that T cells can be involved in acute-phase CML. CML-T1 should be useful in studying this process as well as that underlying Ph-chromosome-negative CML.

[Empiric therapy with aztreonam for febrile neutropenic patients with hematological malignancies]

Combination of aztreonam/amikacin/ticarcillin (AAT) and latamoxef/amikacin/ticarcillin (LAT) were compared in a prospective randomized trial of empiric therapy for febrile neutropenic patients with hematological malignancies. Low dose amphotericin B was also added to each regimen from the beginning. Of 45 evaluable episodes, 23 were treated with AAT and 22 with LAT. The response rates were 61 percent for AAT and 50 percent for LAT, statistically not significant. There was one infection-related death among patients assigned to AAT therapy and also one among those assigned to LAT therapy. Dose escalation of amphotericin B seemed to be effective for those patients who did not improve with initial therapy.

[ATL (adult T-cell leukemia/lymphoma)]

128 cases of ATL (adult T-cell leukemia/lymphoma) were divided into 3 subgroups, 70 cases of acute type, 19 cases of chronic type and 39 cases of lymphoma type, and their prognosis were evaluated. Median survival time from the onset of acute type using Kaplan-Meier method was 8 months, that of lymphoma type was 14 months and that of chronic type was 50 months. Median survival time from the start of treatment of acute type was 5 months, that of lymphoma type was 11 months and that of chronic type was 22 months. Relatively short median survival time of chronic type may be due to they had some duration with observation only at first. No significant elongation of survival time could be obtained when acute type was divided into 2 stages, before and after 1982. Twelve patients with non-Hodgkins' lymphoma unresponsive to the first line combination chemotherapy were treated with combination therapy with cis-dichlorodiammineplatinum (CDDP). Ten patients were evaluable for response (4 cases of CR, 6 cases of PR). To stop the HTLV-1 carrier mothers milk for giving their children seems to be effective method to decrease the occurrence of ATL in future.

Adult T cell leukaemia cells are of CD4+ CDw29+ T cell origin and secrete a B cell differentiation factor

Cells from six cases of adult T cell leukaemia were studied with respect to phenotypical and functional features. All cells were reactive with anti-CD4 and anti-CDw29 monoclonal antibodies (antibody against helper inducer T cells) but were unreactive with anti-CD45R monoclonal antibody (antibody against suppressor inducer T cells). Functionally, these cells secreted a B cell differentiation factor detected by SKW6-CL4 cell differentiation to IgM-producing cells, this secretion being enhanced by culture with recombinant IL-2. Though these results indicate that adult T cell leukaemia cells are of mature helper inducer T cell origin, these cells strongly suppressed PWM-induced B cell differentiation in the absence of CD8+ suppressor effector T cells.

High risk of mother-to-child transmission of HTLV-I in p40tax antibody-positive mothers

A new enzyme-linked immunosorbent assay (ELISA) for detecting the antibody to a human T-lymphotropic virus type I (HTLV-I) tax gene product, p40tax, has been developed. By this ELISA method, we have investigated the relationship between the presence of p40tax antibody in HTLV-I-infected mothers and the virus transmission rate from mothers to their children. The rate of mother-to-child transmission of HTLV-I was higher in p40tax antibody-positive mothers than in antibody-negative ones. Thus, the presence of p40tax antibody may indicate an increased risk of vertical transmission of HTLV-I.

[Difference of antibody profile for human T-lymphotropic virus type-I (HTLV-I) among individuals]

Healthy carriers, patients with ATL and HTLV-I associated myelopathy (HAM) were examined for HTLV-I antibodies of IgG and IgM classes and anti-p 40x antibodies, using ELISA, western blot (WB) and particle agglutination (PA) techniques. IgG antibodies were almost always detectable in sera from all of patients with ATL and HAM and healthy carriers with high titer in the PA test (normal carriers), and the average value of OD 405 was 2.0 +/- 0.3, 1.6 +/- 0.6 and 1.3 +/- 0.7, respectively. In anti-p 40x antibodies, the detectable incidence of HAM, ATL, normal carriers and carriers with low titer of the PA (low-PA group) was 90%, 67%, 44%, and 3%; and, the average value of OD 405 of the antibodies was 2.3 +/- 1.0, 0.7 +/- 0.5, and 0.7 +/- 0.7, respectively. On the other hand, the incidence of IgM antibodies demonstrated in HAM, ATL, normal carriers and low-PA group was 90%, 41%, 33%, and 53%, respectively. Furthermore, the follow-up observation of these antibodies revealed that the antibody profile of individuals for a long time was constant, i.e. in each carrier the value with high OD remained high and the presence of anti-p 40x and/or IgM antibodies remained present. These data has demonstrated that there are considerably differences among individuals in responsivilities for HTLV-I. Then, the antibody profile is mainly classified into 3 groups; hyper-, common- and hypo-immune patterns.

[Significance of the chromosomal findings in acute myeloid leukemia with maturation (M2)]

Chromosomal banding studies were performed on 13 patients with acute myeloid leukemia with maturation (M 2). Six patients revealed t (8;21) (q22;q22), five normal karyotype, and the remaining two +8 and inv (16) (p13 q22), respectively. Apparent pseudo-Pelger-Huët anomalies in mature neutrophils were observed in all the 6 patients with t (8;21), but in only one of the 5 patients with normal karyotype. Neutrophil alkaline phosphatase (NAP) score decreased in all but one in the former group while it increased in all the patients in the latter group. The former group had a median follow-up of 20.8 months or more, whereas the latter group had a median survival of 4.4 months or more. Accordingly, it was suggested that two major chromosome subgroups may be present among patients diagnosed as having M 2: one subgroup with t (8;21) and the other with normal karyotype. One patient with M 2 and inv (16) showed almost the same hematologic features as those observed in patients with acute myelomonocytic leukemia (M 4) and inv (16) except for a small population (6.8%) of monocytoid cells in the bone marrow.

[Effects of low dose Ara-C regimen in acute leukemias and RAEB]

Recent increase of leukemia among elderly patients prompted us to investigate the types of leukemia which can be induced into remission by low-dose Ara-C (LDAC) regimen. LDAC regimen was performed in 30 cases with overt acute leukemia (A), hypoplastic leukemia (B), and RAEB (C); Group A consists of M1 (1 case), M2 (4 cases), M3 (1 case), M4 (4 cases), M6 (1 case), and ALL (2 cases), Group B AML (8 cases), ALL (2 cases), and null (1 case), Group C RAEB (2 cases), and RAEB-T (4 cases). Complete remission (CR) rate was 23% (3/13) in group A, 64% (7/11) in group B, 0% (0/6) in group C. Partial remission rate was 33% (2/6) in group C. In group A, patients with M2 were induced into CR. In group B, both AML and ALL were induced into CR. Hypocellular marrow indicating low leukemic burden related to good sensitivity to Ara-C. Duration of CR was rather short; mean duration being 5.3 months. In group C, 2 PR cases of RAEB showed partial hematological recovery. LDAC regimen is effective especially for most of hypoplastic leukemia and some of M2. Side effects were tolerable, but all CR cases passed through bone marrow hypoplasia and needed supportive cares.

Changes in T wave morphology during hypercalcemia and its relation to the severity of hypercalcemia

The effect of hypercalcemia on T wave morphology, polarity, and amplitude was studied in 14 patients with a primary diagnosis of malignant lymphoma (8 patients), adult T-cell leukemia (5 patients), and Hodgkin's disease (1 patient). Hypercalcemia was severe to extreme in 11 (14.9-22.8 mg/dl), moderate in 1 (13.4 mg/dl), and mild in 2 (11.8 and 12.2 mg/dl) patients. Ten of the 11 patients (91%) with severe hypercalcemia showed inverted, biphasic, and notched T waves, mainly in the chest leads. Notched T waves were observed in all 10 of these patients in anterior to lateral, mid to lateral, or lateral chest leads. Biphasic and/or inverted T waves in anterior or anterior to midchest leads were present in 4 of these 10 patients who had extreme hypercalcemia (greater than 16 mg/dl). Changes in T wave morphology were not observed in moderate or mild hypercalcemia. T wave amplitude showed significant inverse correlation with serum calcium (T mV vs Ca, r = -0.60, p less than 0.001; T/R ratio vs Ca, r = -0.68, p less than 0.001; n = 35). Decrease in T wave amplitude was marked in severe hypercalcemia (p less than 0.0001) and moderate hypercalcemia, but there was no change in mild hypercalcemia. Changes in T wave morphology, polarity, and amplitude either appeared with development of hypercalcemia or disappeared with normalization of serum calcium level. It was concluded that in addition to shortening the QT interval, severe to extreme hypercalcemia can cause development of inverted, biphasic, or notched T wave with a marked decrease in amplitude of T waves.

Immunoglobulin classes of antibody for human T-lymphotropic virus type-I (HTLV-I) in healthy donors and HTLV-I-associated disorders

Healthy blood donors, patients with adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy (HAM) and recipients of unscreened blood (SR) who had seroconverted and were followed-up for more than 2 years were examined for HTLV-I antibodies of immunoglobulin G (IgG) and M(IgM) classes. The overall infection rate in donors was 4.9%, as determined by screening with a particle agglutination method (PA). The rate increased with increasing age. Positive sera with a low titer in the PA test (1/16, 1/32 and 1/64) contained IgM antibodies in 32.5% (titer 1/16) to 36.1% (titer 1/64) of the cases, but IgG antibodies were detected in only 5.6% of the sera with a titer of 1/16 and in 36.1% of the sera with a titer of 1/64. Conversely, in high titer sera (1/128 or higher) IgG antibodies were almost always detectable (99.0%) and IgM antibodies less frequently (25.5%). Sera from acute, chronic and pre-ATL, HAM and SR patients contained IgG antibodies in high titer in all cases. The incidence of IgM antibodies was 7.7, 30.0, 53.3, 72.3, and 77.8%, respectively. IgM antibodies were demonstrated repeatedly in some cases who were followed up for a year. Only IgM antibodies from HAM patients occurred in high titers and had strong reactivity to the p24 antigens of HTLV-I in Western blot testing. It is concluded that it is important to detect IgM antibodies not only in primary infections but also in persistent infections of HTLV-I.

[Translocation (8; 22) (q24; q11) and Epstein-Barr viral genome in a case of Burkitt's type of acute lymphoblastic leukemia (L3)]

A case of Burkitt's type of acute lymphoblastic leukemia (FAB L3) in an 80-year-old male patient is reported. At the time of diagnosis, 74% of the bone marrow cells were lymphoblastoid cells, which were large and homogeneous in size, and whose cytoplasm was abundant and intensely basophilic containing many vacuoles. Lambda-light chains were detected as surface immunoglobulin (Ig), but not heavy chains or kappa-light chains. Epstein-Barr (EB) viral genome was detected in the cultured bone marrow cells by spot hybridization method. Chromosomal banding studies of bone marrow cells revealed t(8; 22) (q24; q11) in all the 18 metaphases examined. This translocation brings the Ig lambda-light chain gene on chromosome 22q11 to chromosome 8q24 where the c-myc proto-oncogene is localized, which is thought to be closely associated with the leukemogenesis of this disorder, whereas EB viral genome is observed in African Burkitt's lymphoma. To our best knowledge, however, there have been no reported Japanese patients with L3 ALL in whom t(8; 22) or EB viral genome was observed.

[Marked dysmyelopoiesis after induction chemotherapy in a case of acute myelomonocytic leukemia (M 4) with t(6; 11)]

A case of AML (M 4) with t(6; 11) showed recovery to myelodysplastic syndrome (MDS)-like bone marrow after one course of DCMP regimen. Dysplastic changes of three cell-lineages were observed and micromegakaryocytes were markedly increased in number. Recovering hematopoiesis was incomplete. During MDS-like phase, t(6; 11) disappeared, reverting to normal karyotypes. Low dose ara-C regimen did not show any effect. AML soon relapsed with reappearance of t(6; 11). MDS-like abnormal hematopoiesis has recently been reported to occur after remission induction therapy or at the time of relapse. G-6PD isozyme study revealed in a remission case of AML that hematopoiesis still consisted of abnormal clone in spite of karyotypic normalization. The abnormal hematopoiesis observed in our case can be referred to such a clonal disorder predominating after disappearance of blastic component of AML. It seems important to reveal what proportion of de novo AMLs shows such an abnormal hematopoiesis and to establish suitable therapeutic approach.

[Chromosome 21 rearrangement in a case of therapy-related myelodysplastic syndrome in multiple myeloma]

A case of therapy-related myelodysplastic syndromes (t-MDS) in 66-year-old male patient is reported. The patient was diagnosed as having multiple myeloma in July 1983. Cyclophosphamide was given since September 1984, and melphalan was added since June 1986. Radiation therapy was not performed. Mild, slowly aggravating pancytopenia developed in July 1987. By December 1987, the hemoglobin level dropped to 6.0 g/dl, leukocytes to 2,800/microliters, and platelets to 15,000/microliters. At that time, 27% of the bone marrow cells were blasts and 23.3% monocytoid cells. Based on these findings, a diagnosis of t-MDS was made. He was managed by supportive care only, but the monocytoid cells increased rapidly in number and he died of pulmonary bleeding in March 1988. Chromosomal banding studies of the bone marrow cells revealed dir ins [inv (17) (p13q21); 21] (q21; p13q22) in all the 11 metaphases examined, but chromosomes No. 5 and 7 were normal. However, Keldsen et al reported that chromosome 21q rearrangements were nonrandomly associated with t-MDS and t-acute nonlymphocytic leukemia.