Trisomy 19 in a patient with myelodysplastic syndrome and thrombocytosis

A patient with refractory anemia with excess blasts, ringed sideroblasts, and thrombocytosis was found on cytogenetic analysis to have trisomy 19 as the sole abnormality. Although trisomy 19 in combination with other chromosomal anomalies has been encountered in association with a variety of hematologic malignancies, many solid tumors, and the myelodysplastic syndrome, its occurrence as the only cytogenetic aberration is rare and has not been reported in association with thrombocythemia.

Flow cytometric analysis of megakaryocytes from patients with abnormal platelet counts

Megakaryocytes (MKs) from 40 patients with quantitative platelet disorders and 19 normal volunteers were analyzed by flow cytometry for size, fine cell internal structure and granularity, membrane expression of the glycoprotein (GP) IIb/IIIa complex, and for ploidy distribution. Analysis was performed on unfractionated minimally manipulated marrows obtained from routine bone marrow aspirates. MKs were labeled with a fluorescent lineage-specific monoclonal antibody to the GPIIb/IIIa complex followed by DNA staining with propidium iodide. Eight hundred to 3,000 MKs were analyzed in each sample. The modal ploidy distribution in normals was 16N, comprising about half of the megakaryocytic population, with 22.6% of the cells less than or equal to 8N and 22.0% greater than or equal to 32N. Twelve thrombocytopenic patients with decreased marrow MKs on biopsy (mean platelet count [MPC] 44,600/microliters) showed an increase in low ploidy cells with 53.2% less than or equal to 8N (P less than .01); cell size was reduced in three patients when compared to normal cells of identical ploidy (P less than .05). Eight thrombocytopenic patients with enhanced platelet destruction (with normal or increased MKs on biopsy and shortened platelet survival; MPC 41,400/microliters) showed an increased proportion of high ploidy cells greater than or equal to 32N to 39.2% (P less than .01). Increased cell size and granularity were found in four of these patients (P less than .05). Six patients with thrombocytopenia secondary to multiple mechanisms affecting both platelet production and destruction (MPC 66,700/microliters) showed no shift in ploidy. Four patients with primary thrombocytosis (two with thrombocythemia and two with polycythemia vera; MPC 822,500/microliters) showed a marked shift toward high ploidy cells with 42.3% greater than or equal to 32N and 7.6% greater than or equal to 64N cells (P less than .01). The shift was accompanied by a marked increase in cell size and granularity in the patients with thrombocythemia. Ten patients with thrombocytosis secondary to chronic blood loss, malignant or inflammatory disorders (MPC 714,000/microliters), showed variable distributions with four patients exhibiting a shift in ploidy to the right similar to that found in the patients with increased platelet destruction. Based upon the present data, flow cytometric ploidy distribution may be diagnostically useful in thrombocytopenic patients by discriminating between disorders of platelet production and destruction. (ABSTRACT TRUNCATED AT 400 WORDS)

[The 5q-syndrome--report of two cases]

Case 1. A 67-year-old man was admitted to our hospital because of fever, diarrhea and abdominal pain. Hemoglobin was 10.7 g/dl, white cell count 6,900/microliters and platelet count 36.7 x 10(4)/microliters. Bone marrow biopsy showed non-lobulated megakaryocytes. The karyotype was 47, XY, +8, -16, 5q-, + mar. We have followed up this case without any special treatment except for red blood cell transfusions. The platelet count has increased to 70.9 x 10(4)/microliters. Case 2. An 84-year-old man was admitted to our hospital because of tinnitus and headache. Hemoglobin was 7.9 g/dl, white cell count 1,200/microliters and platelet count 22.5 x 10(4)/microliters. Bone marrow biopsy showed hypocellular marrow and non-lobulated megakaryocytes. The karyotype was 46, XY, 5q-. We have followed up this case only with red blood cell transfusions. The platelet count has increased to 68.9 x 10(4)/microliters. The hematological findings and clinical courses of the two cases were similar to those in the 5q-syndrome first described by Van den Berghe et al. in 1974. And these cases are important in relation to c-fms oncogene and hematopoietic abnormalities.

Circulating human blood platelets retain appreciable amounts of poly (A)+ RNA

Platelets lack a nucleus and are usually considered to be incapable of protein synthesis due to an apparent lack of messenger RNA, precluding the construction of platelet cDNA libraries and hindering the cloning of authentic platelet cDNA's. We reasoned that vestigial amounts of messenger RNA may remain in platelets when they first separate from the megakaryocyte and circulate in the peripheral blood. We isolated poly (A)+ RNA from platelets obtained by pheresis of individuals with elevated blood platelet counts due to a myeloproliferative syndrome termed essential thrombocythemia. Northern blots using probes for platelet glycoprotein Ib indicate that the poly (A)+ RNA obtained from the platelets of these donors is, in fact, derived from platelets. Cell free translation studies using the platelet poly (A)+ RNA indicate that the material is translationally active. We conclude that, contrary to prevailing information, circulating human blood platelets retain appreciable amounts of poly (A)+ RNA and that this RNA can be harvested by the described approach. The poly (A)+ RNA provides templates for the synthesis of cDNA's that code for platelet proteins.

Trisomy 9 in hematologic disorders: possible association with primary thrombocytosis

Ten patients with a hematologic disorder and a clone of cells with trisomy 9 in the bone marrow were studied in order to investigate the clinical significance of this chromosome anomaly. In five of the patients, trisomy 9 was the only anomaly; in four, there was also trisomy 8; and in one, a Y chromosome was also lacking. Four patients had a myelodysplastic syndrome, and six had a myeloproliferative disorder. Interestingly, four patients had primary thrombocytosis.

Essential thrombocytosis with the Philadelphia chromosome (Ph')

Essential thrombocytosis is a myeloproliferative disease not known to have consistent cytogenetic abnormalities. A 46-year-old black woman with essential thrombocytosis and a Philadelphia chromosome is reported. Iron deficiency and tuberculosis were present but when effectively treated did not result in resolution of thrombocytosis. Megakaryocytic hyperplasia of bone marrow, abnormal platelet function studies and a compatible clinical state suggested the diagnosis of essential thrombocytosis. The diagnostic criteria for other myeloproliferative diseases were not met. The Philadelphia chromosome was consistently obtained from bone marrow preparations. We conclude that the Philadelphia chromosome may be found in essential thrombocytosis as well as other, previously reported, myeloproliferative diseases.

Translocation t(3;20) associated with thrombocythemia in Ph-positive CML

A patient with Philadelphia (Ph) chromosome positive chronic myelocytic leukemia is described who also developed an abnormality of chromosome #3, i.e., t(3;20)(p21;p13), in blast crisis. This abnormality may be connected with the advent thrombocythemia. The disease was a thrombopenia in the initial phase.

Analysis of haemopoiesis: the use of cell markers and in vitro culture techniques in studies of clonal haemopathies in man

The clonal haemopathies have in common the expansion of a neoplastic stem cell which has retained a variable capacity for differentiation to granulocytes, monocytes, erythrocytes, and platelets. Although normal stem cells are present in such patients, their differentiation is somehow suppressed. However, their presence may be demonstrated either by cell culture studies, employing G6PD as the marker in appropriately selected cases, or by their emergence in patients subjected to marrow ablative chemotherapy. Suppression of normal stem cell growth and development does not require a hyperproliferative marrow, and the current data do not support the notion that normal stem cells are simply reduced in frequency by a vast increase in the numbers of neoplastic progenitors. It is likely, therefore, that such suppression involves cellular signals, operating over short distances (perhaps through cell-to-cell contact), which interfere with normal progenitors. Thus, stem cell culture techniques, in combination with cell markers, have provided a direct and informative way to approach the issues of disease pathogenesis, the kinetics of stem cell differentiation, and the interaction of normal and neoplastic cells in patients with clonal haemopathies.

Absence of a specific chromosomal marker in essential thrombocythemia

In 33 patients with essential thrombocythemia, a specific chromosomal abnormality ( 21q -) could not be confirmed. All patients in this series met rigid criteria for diagnosis of this myeloproliferative disorder.

Two adult siblings with thrombocytopenia and a familial 13;14 translocation

A woman with thrombocytopenia that progressed to aplastic anemia, and her brother, who had persistent thrombocytopenia, both had a constitutional t(13;14) translocation. Six other family members, in three generations, had the same translocation, but no hematologic disorder. There was evidence suggestive of increased chromosomal fragility in lymphocyte cultures from two members of the kindred, but not in the two patients. The findings support a postulated association between the t(13;14) and hematologic disorders, but whether the mechanism involves an inherited defect in chromosomal stability is unproved.

[Thrombocythemia with Philadelphia chromosome. Secondary appearance of chronic myeloid leukemia]

The finding of a Philadelphia chromosome in a case of apparently primary thrombocythaemia should change the diagnosis for that of chronic myeloid leukaemia. This theoretical view is supported by the case reported here, where a Philadelphia-chromosome was detected in the bone marrow cells of a patient with severe thrombocythaemia; a typical myeloid leukaemia developed 21 months after the onset of the disease; survival was of short duration.

Essential thrombocythemia: a clonal disorder of hematopoietic stem cell

We studied 5 patients with essential thrombocythemia utilizing glucose-6-phosphate dehydrogenase (G-6-PD) enzyme as a cell marker for determining clonality. One of the patients was found to be heterozygous for isoenzymes B and A in the nonhaemopoietic tissues such as fibroblasts, but manifested only isoenzyme type B in the erythrocytes, neutrophils, and platelets. Our studies support the concept that essential thrombocythemia is a clonal disorder arising in a multipotent stem cell.

Rearrangement of chromosome no. 3 in a case of preleukemia with thrombocytosis

The clinical and cytogenetic findings of a patient with the preleukemic syndrome and a structural rearrangement involving both chromosomes No. 3 are described. The karyotypic abnormality consisted of an insertion of a part of the long arm of one chromosome No. 3 into the other, i.e., ins(3;3)(q27;q21q27). A prominent feature of the bone marrow was a marked megakaryocytic hyperplasia. The platelet count temporarily exceeded 1000 x 10(9)/liter. The findings of the present case, together with similar observations by others, suggest that the long arm of chromosome No. 3 may contain a region involved in the regulation of megakaryopoiesis.

Primary thrombocythemia: clonal origin of platelets, erythrocytes, and granulocytes in a GdB/GdMediterranean subject

A patient with primary thrombocythemia, who was heterozygous for glucose-6-phosphate dehydrogenase deficiency (GdB/GdMed), was investigated to test for the clonal origin of this myeloproliferative disorder. In order to assess somatic cell mosaicism in various tissues, we have made use of the different rate of utilization of 2-deoxyglucose-6-phosphate, an analog of glucose-6-phosphate, by normal glucose-6-phosphate dehydrogenase and by the Mediterranean variant: the results demonstrate that essential thrombocythemia is a clonal disease involving the erythrocytic, granulocytic, and megakaryocytic series, without affecting monocytes, T lymphocytes, and non-T lymphocytes.

A complex Ph1 translocation in a patient with primary thrombocythaemia

Routine blood examination of a 27-year-old female revealed a platelet count of 2000 X 10(9)/l. Bone marrow cells showed the Philadelphia chromosome which was one product of a complex rearrangement of chromosomes 9, 22 and X. Her platelet count was lowered by plateletphoresis and chemotherapy. She remains in good health 19 months later, but her thrombocythaemia is considered to be an early manifestation of chronic myeloid leukaemia.

A chromosomal abnormality (21q-) in primary thrombocytosis

A patient with thrombocytosis was found to present an acquired deletion of the long arm of chrosome 21 (21q-). A similar observation reported in the literature is hereby confirmed.

Macrocytic anemia, thrombocytosis and nonlobulated megakaryocytes: the 5q-syndrome, a distinct entity

The clinical, hematologic and histologic characteristics of six patients with refractory anemia with deletion of the long arm of chromosome No. 5 are described. These patients had a distinct hematologic picture with macrocytic anemia of mild to moderate severity, normal to low leukocyte count and increased platelet count. The long arm of chromosome No. 5 was deleted in the majority of bone marrow metaphases. The main cause of anemia was underproduction with decreased erythroid precursors in the bone marrow and no increase in peripheral blood reticulocytes. Two of five patients responded transiently to the administration of androgens. In vitro evaluation of the bone marrow growth pattern in semisolid agar culture system was performed in three patients and was found to be normal and distinct from that in patients with preleukemia. In a follow up of up to five years, no patient had changed hematologically and in none had leukemia developed. The 5q-syndrome is a distinct hematologic entity and probably more common than hitherto realized. This diagnosis may have therapeutic and prognostic implications.

Effect of busulfan on oncornavirus-like activity in platelets and chromosomes in polycythemia vera and essential thrombocythemia

The effect of busulfan therapy on the activity of oncornavirus-like particles and chromosome patterns in patients with polycythemia vera and essential thrombocythemia was studied. Three patients had pretreatment platelet counts greater than 1 million/microliter, abnormal bone marrow karyotypes, and electron microscopic and biochemical evidence of oncornavirus. The results demonstrated that in all 3 patients virus-like particles and reverse transcriptase-like activity could no longer be found in the platelets within 2-4 weeks after the initiation of busulfan treatment. The platelet count was still elevated at this point for each patient, although the count returned to normal levels within 2-3 weeks after virus-like activity was no longer detectable. The chromosome patterns, characterized by aneuploidy (30-50%) before treatment, improved after therapy.