Demonstrated Benefit of Continuous Interferon-Alpha-2b Therapy in Hairy Cell Leukemia. A Two-Year Follow-Up

Interferon-alpha-2b (IFN) was given to a series of 50 patients with hairy cell leukemia (HCL). The IFN dose for both induction and maintenance was 2.0 × 10(6) IU/m(2) s.c. three times weekly. At 24 months 38 patients remained in the study. The proportion of complete responders (CR) increased during the follow-up, and had at 24 months reached 58%, while 28% at the same time had a partial (PR) and 14% a minor response (MR). During the two years of continuous IFN treatment none of the 38 patients showed any signs of relapse. The response rate was similar between splenectomized (n = 15) and non-splenectomized (n = 23) patients, but the rise in platelets was much steeper and reached a significantly higher plateau in patients, who previously had undergone splenectomy. The IFN therapy was generally well tolerated, but when evaluated at 24 months at least some (mostly mild) toxicity was noted in 76% of the patients. None of the patients developed neutralizing antibodies to IFN.

A multicentre study of reference intervals for haemoglobin, basic blood cell counts and erythrocyte indices in the adult population of the Nordic countries

Eight haematological quantities were measured in EDTA anticoagulated venous blood specimens collected from 1826 healthy male and female individuals between 18 and 90 years of age in the Nordic countries (Denmark, Finland, Iceland, Norway and Sweden). The samples, collected between November 1999 and November 2001 as part of the Nordic Reference Interval Project (NORIP), were analysed on 12 different types of modern automated haematology instruments currently in use among the 60 laboratories participating in the study. Non-parametric reference intervals (between 2.5 and 97.5 percentiles) have been calculated for B-Haemoglobin (females 117-153 g/L, males 134-170 g/L), B-Erythrocytes (females 3.94-5.16 x 10(12)/L, males 4.25-5.71 x 10(12)/L), B-EVF (females 0.348-0.459, males 0.395-0.500), B-MCV (82-98 fL), Erc-MCH (27.1-33.3 pg), Erc-MCHC (317-357 g/L), B-Trc (females 165-387 x 10(9)/L, males 145 x 348 x 10(9)/L) and B-Lkc (3.5-8.8 x 10(9)/L). Partitioning of data according to age and gender was done according to a standardized procedure. For most variables the calculated reference intervals corresponded well with older and less well-defined reference intervals. The mean concentration of B-Haemoglobin increased by 0.08 g/L per year of age in women, and decreased by 0.1 g/L per year of age in men. B-Haemoglobin increased with body mass index in both men and women. Smoking increased the mean of B-Lkc by 1.1 x 10(9)/L and regular use of alcohol increased the mean of B-MCV by 0.8 fL. The influence of these factors was small overall and did not promote specific reference intervals.

Malabsorption of vitamin B12 in dermatitis herpetiformis and its association with pernicious anaemia

Serum vitamin B12 concentrations were determined in 129 patients and a pentagastrin test performed in 116 patients with dermatitis herpetiformis (DH). Low serum vitamin B12 levels were found in 27 patients (21%) and achlorhydria in 30. Forty-two patients with achlorhydria and/or vitamin B12 deficiency were subjected to further haematological and gastrointestinal investigations. Functional or morphological involvement of the small intestine was seen in almost all patients with vitamin B12 deficiency but, in addition, atrophic gastritis resulting in defective secretion of intrinsic factor (pernicious anaemia) was found in 8 cases (7% of all DH patients). Thus, a low vitamin B12 level in DH patients should result in a careful gastrointestinal examination as both an atrophic gastritis and a coeliac-like enteropathy have further clinical implications.

Acute myeloid leukemia appearing in two patients after prolonged continuous chlorambucil treatment for Wegener's granulomatosis

Two patients with Wegener's granulomatosis have been treated with chlorambucil and prednisolone continuosly for 3 and 5 years, respectively. This treatment was effective in controlling the disease, but bone marrow toxicity with severe pancytopenia developed in both cases. Both patients died from thrombocytopenia with haemorrhagic pericarditis. In one case, the diagnosis of acute myeloid leukaemia was established from the appearance of myeloblasts in the peripheral blood and from characteristic bone marrow morphology. In the other case this diagnosis was strongly suspected on the basis of the bone marrow morphology alone. It is proposed that this development of acute leukaemia in two patients with a primary non-neoplastic disease may result from a direct carcinogenic action of chlorambucil in humans.

Differential counting of blood leukocytes using automated microscopy and a decision support system based on artificial neural networks--evaluation of DiffMaster Octavia

The morphological appearance of blood cells has an established association to clinical conditions. A novel system, DiffMaster Octavia for differential counting of blood leukocytes, has been evaluated. The system consisted of a microscope, 3-chip color charge coupled device (CCD) camera, automated motorized stage holder, electronic hardware for motor and light control and software for automatic cell location and image processing for preclassification of blood cells using artificial neural networks. The DiffMaster test method, was evaluated on 322 routine blood samples (400 cells per sample) using manual microscopy as reference method. The results showed a correlation of determination (r(2)) of 0.8-0.98 for the normal cell classes and blast cells. The DiffMaster correctly preclassified 89% of all leukocytes with a good reproducibility. After verification of the cell classes, the agreement between the test and reference method was 91% whether the sample was abnormal or normal. The clinical sensitivity was 98% and specificity 82%. The sensitivity to identify blast cells was slightly higher with the DiffMaster than manual microscopy. Similar levels of short-term imprecision for the two methods were found for all cell classes. In conclusion this study shows that the DiffMaster can provide a decision support system which, together with a qualified morphologist, can generate leukocyte differential count reports of high quality.

Increased serum erythropoietin concentration after allogeneic compared with autologous blood transfusion

Serum erythropoietin (sEPO) level is known to increase as hemoglobin (Hb) concentration decreases during and after preoperative autologous blood donation (PAD). The endogenous erythropoietin (EPO) production after allogeneic blood transfusion has not to our knowledge, been studied. The aim of the present study was to determine whether there is, after surgery, any change in sEPO concentration after allogeneic blood transfusion, and whether there is any difference in EPO response after autologous or allogeneic blood transfusion. Thirty-one patients approaching total hip-joint replacement surgery, were randomized to receive either allogeneic red blood cells (n = 15) or predeposited autologous whole blood transfusion (n = 16). The relationship between Hb, sEPO, and reticulocytes in the recipients were repeatedly analyzed before, during and after surgery. The Hb followed an expected pattern, with a decreased concentration after PAD in the autologous group, then in both groups after surgery. The sEPO concentration was significantly higher in the allogeneic than in the autologous group on day one and day 4-5 postoperatively. The reticulocyte level, on the contrary, was higher in the autologous patients before, one hour after, and one day after surgery. The study showed a greater increase in sEPO concentration after allogeneic blood transfusion than after autologous blood transfusion. There may be an inverse relationship between sEPO and the reticulocyte level.

Basis of hematopoietic defects in platelet-derived growth factor (PDGF)-B and PDGF beta-receptor null mice

Platelet-derived growth factor (PDGF)-B and PDGF beta-receptor (PDGFR beta) deficiency in mice is embryonic lethal and results in cardiovascular, renal, placental, and hematologic disorders. The hematologic disorders are described, and a correlation with hepatic hypocellularity is demonstrated. To explore possible causes, the colony-forming activity of fetal liver cells in vitro was assessed, and hematopoietic chimeras were demonstrated by the transplantation of mutant fetal liver cells into lethally irradiated recipients. It was found that mutant colony formation is equivalent to that of wild-type controls. Hematopoietic chimeras reconstituted with PDGF-B(-/-), PDGFR beta(-/-), or wild-type fetal liver cells show complete engraftment (greater than 98%) with donor granulocytes, monocytes, B cells, and T cells and display none of the cardiovascular or hematologic abnormalities seen in mutants. In mouse embryos, PDGF-B is expressed by vascular endothelial cells and megakaryocytes. After birth, expression is seen in macrophages and neurons. This study demonstrates that hematopoietic PDGF-B or PDGFR beta expression is not required for hematopoiesis or integrity of the cardiovascular system. It is argued that metabolic stress arising from mutant defects in the placenta, heart, or blood vessels may lead to impaired liver growth and decreased production of blood cells. The chimera models in this study will serve as valuable tools to test the role of PDGF in inflammatory and immune responses. (Blood. 2001;97:1990-1998)

No increased frequency of trisomies 8 and 9 by fluorescence in situ hybridization in untreated patients with essential thrombocythemia

Essential thrombocythemia (ET) is one of the diseases included among the myeloproliferative disorders in which trisomies for chromosomes 8 and 9 commonly occur. In ET, only a few patients are known to show clonal abnormalities. With fluorescence in situ hybridization (FISH), interphase cells can be evaluated and clones can be detected even though not revealed by conventional cytogenetic methods. By using FISH for enumeration of chromosomes 8 and 9 in bone marrow cells, we studied 22 patients with ET; 20 of them were investigated at the time of diagnosis when they were still untreated with myelosuppressive agents. Only two patients had trisomy 8; one of them was also found to have +8 with conventional cytogenetics. None of the patients had trisomy 9; two patients had borderline values in comparison to a control group. Thus, in ET, no increased frequency of patients with trisomy for 8 or 9 at the time of diagnosis could be detected with FISH.

Masked monosomy 7 in myelodysplastic syndromes is uncommon and of undetermined clinical significance

Masked monosomy 7, i.e. detected by FISH but not by conventional cytogenetics, has been reported in varying frequency in MDS. To establish the prevalence and possible clinical significance of the aberration, we studied the 123 previously karyotyped MDS patients using FISH and a DNA probe specific for chromosome 7. Metaphase cytogenetics revealed ten patients (8%) with monosomy 7 (6 RAEB and 4 RAEB-t). FISH confirmed this result and detected four more cases (4%) with masked monosomy 7 (3 RA and 1 RARS). Thus, masked monosomy 7 is less common than has been suggested, and does not seem to carry the same prognostic weight as monosomy 7 diagnosed by metaphase cytogenetics.

Cytogenetic studies in patients with mastocytosis

Chromosomal aberrations in hematopoietic cells are common in malignant hematological disorders and have also been reported in some patients with mastocytosis. In this study, 34 patients with either urticaria pigmentosa or systemic mastocytosis were investigated by cytogenetic analysis of bone marrow cells. A follow-up investigation was performed in 22 patients. Clones with chromosome abnormalities were found in 32% of the patients at the first examination and in 27% at the second examination; in total, 41% of the patients had an abnormal clone in at least one examination. No clinical correlation was found with regard to cytogenetic results, with the exception of four patients who had an associated hematological disease and poor prognosis. In the second examination, only 6 patients had an unchanged chromosome pattern, and 4 of the patients with an initial normal pattern had appearance of abnormal clones; however, in 7 patients, the initial abnormal cells disappeared. The abnormalities were, among others, deletions of chromosomes 5, 7, 11, and 20. The proportion of cells with structural or numerical chromosome changes was higher in comparison with reported control groups. The frequency and type of chromosome abnormalities in bone marrow cells from patients with mastocytosis was about the same as observed in other chronic myeloproliferative disorders and myelodysplastic syndromes, diseases which also developed in 4 of our patients. An association between malignant hematological disorders and mastocytosis have been suggested by us and others. The chromosome abnormalities maybe reflect a genetic instability of the hematopoietic cells in mastocytosis.

Hydroxyurea treatment reduces haematopoietic progenitor growth and CD34 positive cells in polycythaemia vera and essential thrombocythaemia

The aim of the present work was to investigate the effect of hydroxyurea (HU) treatment on haematopoietic progenitors and CD34 positive (CD34+) cells in patients with polycythaemia vera (PV) and essential thrombocythaemia (ET). Of the PV patients were 10 treated with phlebotomy only and 10 were on HU therapy. Seven ET patients were untreated and 10 received HU. In each subject peripheral blood was obtained for in vitro colony growth, determination of CD34+ cells and plasma erythropoietin (EPO) concentration. The mean number of EPO independent erythroid colonies (EEC) was higher in the group of PV patients on phlebotomy therapy compared to the PV patients treated with HU (74.4 and 8.0 colonies/10(5) cells, respectively) but the difference did not reach statistical significance. The corresponding means for the untreated ET patients and ET patients treated with HU were 13.0 and 1.3 colonies/10(5) cells, respectively, this difference being statistically significant (p = 0.012). The mean EEC for combined groups of PV and ET without myelosuppressive treatment were compared with the results for PV and ET patients on HU therapy; this difference was statistically significant (p = 0.014). The same pattern was observed for total erythroid growth with EPO. The relationship between the concentration of CD34+ cells and total EEC in peripheral blood was statistically significant for both PV (p<0.005) and ET (p<0.01). This finding supports the hypothesis that the level of CD34+ cells in peripheral blood could be used as a proliferation marker in these two myeloproliferative entities. No relationship between plasma EPO and EEC was present. It therefore appears that the reported differences in plasma/serum EPO concentrations between PV patients on phlebotomy treatment compared to patients on myelosuppressive treatment are not likely to be found at the production site for erythrocytes.

Plasma erythropoietin concentrations in polycythaemia vera with special reference to myelosuppressive therapy

In 80 patients with polycythaemia vera (PV) a total of 108 venous blood samples were obtained and analysed for EDTA-plasma erythropoietin (EPO) concentration. At the time of study 21 of the PV patients were newly diagnosed and had prior to blood sampling neither received phlebotomy treatment nor therapy with myelosuppressive agents; these subjects had a mean plasma EPO concentration of 0.5+/-0.9 IU/L. Thirty-seven patients treated with phlebotomy only had a mean plasma EPO concentration of 2.5+/-2.9 IU/L. The mean plasma EPO concentrations for 26 patients treated with hydroxyurea, 13 patients treated with radiophosphorous and 11 patients given a combination of myelosuppressive agents were 8.9+/-8.0, 10.9+/-12.6 and 7.2+/-7.4 IU/L, respectively. Untreated patients and patients on phlebotomy only had significantly lower values for plasma EPO than patients on therapy with myelosuppressive drugs. This finding persisted also after a correction for differences in haemoglobin levels had been introduced. Thereby, the present results would suggest a difference in the EPO feedback system in untreated and phlebotomised PV patients compared to PV patients treated with myelosuppressive agents.

Low megakaryocyte ploidy in Ph-positive chronic myelogenous leukemia measured by flow cytometry

In chronic myeloproliferative disorders, the megakaryocytes differ in size and maturation compared with those of healthy individuals. In the present study, by using a 2-color flow cytometry technique, we determined the frequency of bone marrow megakaryocytes in different ploidy classes in 13 newly diagnosed and untreated patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) and in 12 healthy volunteers. The results showed a significant difference in megakaryocyte ploidy distributions between these 2 study groups. On the average, patients with CML had 59% of their megakaryocytes in ploidy classes 2N to 8N; in contrast, the healthy volunteers had only 22% of their megakaryocytes in classes 2N to 8N. Two patients with complex Ph translocation and 2 patients with a small clone with a chromosome abnormality in addition to Ph had the same ploidy distribution as those with only Ph translocation. The platelet count did not correlate with the megakaryocyte mean ploidy.

Bone marrow fibrosis and radiological changes of the long bones in children with acute megakaryocytic leukaemia

The diagnosis of acute megakaryocytic leukaemia (AMkL) may be difficult to establish owing to difficulties in obtaining adequate bone marrow aspirates secondary to bone marrow fibrosis. We describe three children without Down's syndrome under 2 y of age with AMkL. Although none of the patients had the non-random t(1;22) (p13;q13) translocation, bone marrow cells from all patients exhibited chromosome abnormalities with complex karyotypes, including trisomy 21 in two cases. All patients had profound bone marrow fibrosis and characteristic lamellar diaphyseal radiological changes of the long bones.

Serum methylmalonic acid and total homocysteine in patients with suspected cobalamin deficiency: a clinical study based on gastrointestinal histopathological findings

We compared the sensitivity and specificity of the two metabolite tests, methylmalonic acid (MMA) and total homocysteine (Hcy) in serum, and serum cobalamin (Cbl) in patients referred to our hospital because of suspected cobalamin deficiency and a serum cobalamin value at the referring unit <200 pmol/L. All 111 patients included were investigated using upper gastrointestinal endoscopy with biopsy specimens taken from the gastric and duodenal mucosa to find a morphological basis for cobalamin malabsorption as well as the Schilling test for the validation of the serum tests. All patients were treated with cobalamin and new blood samples were taken after 4 weeks. We found no difference in sensitivity and specificity between serum MMA, Hcy, and Cbl in identifying patients with and without conditions compatible with cobalamin malabsorption. Elevated serum MMA and Hcy were also found in about 15% of the group of patients with normal Schilling tests and without a morphological basis for cobalamin malabsorption. Moreover, most patients in this group responded with decreased values of the metabolite tests following cobalamin treatment, suggesting that neither elevated metabolites nor a decrease in these values following cobalamin treatment are specific for cobalamin deficiency.

Increase of CD34 positive cells in polycythaemia vera

The purpose of the present work was to evaluate the proliferative character of polycythaemia vera (PV). Therefore, in 15 patients with different stages of PV we assessed the level of CD34 positive (CD34+) cells in peripheral blood and bone marrow, erythroid colony growth of bone marrow cells and plasma erythropoietin (EPO). The mean concentration of CD34+ cells in blood was significantly increased in PV patients (9.0 +/- 11.2 x 10(3)/mL) compared to healthy controls (2.0 +/- 1.7 x 10(3)/mL). In aspirated bone marrow no such difference between PV and control subjects was present. Six patients with splenomegaly and/or requirement for chemotherapy had significantly higher mean blood levels of CD34+ cells compared to the remaining PV patients. All PV patients presented EPO independent erythroid colonies. Three PV patients with anaemia and long disease duration had high EPO levels.

Prognostic impact of bone marrow karyotype in childhood acute lymphoblastic leukaemia: Swedish experiences 1986-91

The prognostic value of cytogenetic classification in acute lymphoblastic leukaemia (ALL) was evaluated in Swedish children below 16 years of age (n = 372) diagnosed between 1986 and 1991. A bone marrow karyotype was obtained in 281 cases, of which 149 (53%) showed clonal abnormalities. Event-free survival (p-EFS) was 0.64-0.69 in patients with diploid and pseudodiploid karyotype. Patients with massive hyperdiploidy (> 50 chromosomes) had the best outcome (p-EFS = 0.76) and those with hypodiploidy (< 46 chromosomes) had the worst (p-EFS = 0.33). White blood cell count and age were the strongest predictors of outcome. The karyotype reached borderline significance. The diagnostic karyotype was also a predictor of outcome after relapse, with hyperdiploid patients doing better than the others. The presence of a structural chromosomal abnormality did not constitute a negative prognostic factor when intensive chemotherapy was given.

Bullous pyoderma gangrenosum in a patient with myelodysplastic syndrome during granulocyte colony-stimulating factor therapy

An unusual case of bullous pyoderma gangrenosum in a patient with myelodysplastic syndrome during treatment with granulocyte colony-stimulating factor (G-CSF) is reported. The possible relationship between G-CSF therapy and pyoderma gangrenosum, as well as the beneficial effect of cyclosporin A therapy, is discussed.

Spontaneous remission during two pregnancies in a patient with essential thrombocythaemia

A woman with untreated essential thrombocythaemia (ET) exhibited spontaneous normalization of her elevated platelet count during two pregnancies. After delivery the platelet count increased rapidly to the same high level as before. Low platelet adhesion as well as adrenalin- and collagen-induced platelet aggregation, present before pregnancy, increased to normal values during pregnancy. Furthermore, no erythropoietin-independent colony growth was observed during pregnancy, while such colonies were clearly demonstrated when the patient was assayed after pregnancy. This is the second case in the literature demonstrating that remission of ET can occur without treatment during pregnancy.

Flow cytometric analysis of megakaryocyte ploidy in chronic myeloproliferative disorders and reactive thrombocytosis

Megakaryocyte (MK) ploidy patterns were analysed by flow cytometry in 29 newly diagnosed and previously untreated patients with chronic myeloproliferative disorders (MPD) and concomitant thrombocytosis, in 9 patients with reactive thrombocytosis (RT) and in 12 healthy individuals. Unfractionated bone marrow from routine aspirates was used. MKs were identified with a fluorescein labelled monoclonal antibody specific for glycoprotein IIIa (GPIIIa) and DNA was stained with propidium iodide. For the 12 healthy volunteers the mean modal ploidy number was 16 N; the 9 patients with RT displayed an identical MK ploidy pattern. The frequency of MKs with a ploidy > or = 32 N was 45% among the patients with essential thrombocythaemia (ET) compared to 32% among the healthy volunteers (p < 0.001). MKs with ploidy number > or = 64 N, comprising approximately 13% of the total number of MKs, was a characteristic finding in the patients with ET. Similar findings were present in 8 patients with polycythaemia vera (PV). In patients with PV 34% and 6% of the MKs displayed ploidies > or = 32 N and > or = 64 N, respectively. In contrast, a distinct shift towards lower ploidy number, with 63% of MKs < or = 8 N, was found among the 4 patients with chronic myeloid leukaemia (CML). The present results indicate that by using flow cytometric analysis of MK ploidy distribution in patients with thrombocytosis, those with a reactive cause are likely to be discriminated from patients with myeloproliferative thrombocytosis, i.e. PV and ET on one hand and CML on the other hand. The distinction between ET and PV, however, has to be made on other grounds.

Bone marrow progenitor cell growth and karyotype changes in healthy 88-year-old subjects

Previous studies have indicated a decline in bone marrow progenitor cell function in subjects aged 75-82 years, possibly causing lower Hb concentrations. We studied the bone marrow with in vitro colony assays and cytogenetic analysis in 24 apparently healthy 88-year-olds with Hb concentrations ranging from moderate anaemia to normal levels. Twenty-two healthy younger subjects, aged 21-57 years, were used as a control group. The 88-year-olds showed significantly lower numbers of myeloid bone marrow progenitors than the controls, and the elderly men had lower numbers of both erythroid and myeloid progenitors than the elderly women. There were no in vitro growth differences between elderly subjects with "low" or "normal" Hb concentrations. Ten out of 14 men had bone marrow cells with a missing Y-chromosome, which did not seem to have any relationship to the erythroid function. No morphological or other cytogenetic indications of a clonal progenitor cell disorder were found. A more rapid decline in Hb concentrations in healthy elderly men as compared to elderly women might be explained by differences in bone marrow progenitor cell function. However, progenitor cell abnormalities do not seem to explain differences in Hb concentrations within groups of apparently healthy men and women of advanced age.

Mice deficient for PDGF B show renal, cardiovascular, and hematological abnormalities

Platelet-derived growth factor (PDGF) affects the growth, migration, and function in vitro of mesenchymal cells, but little is known about its normal physiological functions in vivo. We show here that mice deficient for PDGF B die perinatally and display several anatomical and histological abnormalities. Kidney glomerular tufts do not form, apparently because of absence of mesangial cells. Instead, a single or a few distended capillary loops fill the glomerular space. The heart and some large arteries dilate in late-stage embryos. Most PDGF B mutant embryos develop fatal hemorrhages just prior to birth. Their hematological status includes erythroblastosis, macrocytic anemia, and thrombocytopenia. On the basis of these findings, we conclude that PDGF B has crucial roles in vivo in establishing certain renal and circulatory functions.

A follow-up study of bone marrow chromosomes and in vitro colony growth in patients with mastocytosis

Proliferation of mast cells can give rise to many clinical manifestations in patients, and an association with hematological disorders has been pointed out. The study was initiated to determine whether patients with mastocytosis show a clinical progression in relation to bone marrow cell parameters analyzed. During a median follow-up period of 5.5 years, 10 patients with mastocytosis were re-examined with regard to clinical symptoms, urine histamine metabolites (U-MeImAA), bone marrow cells examined with chromosome analyses, and in vitro stem cell growth for CFU-GM. Seven patients showed a clinical progression with increase of either symptoms, bone marrow infiltrates of mast cells or U-MeImAA. One patient with a myeloproliferative bone marrow morphology had a malignant course. Four of the 7 patients showed an increased colony growth, while 3 showed a decreased growth, in the second examination compared with the first examination. One patient had a persistent clone with the chromosome aberration 9p+. A variable pattern was observed in the other patients, in resemblance with findings in chronic myeloproliferative disorders. Our conclusion is that mastocytosis belongs to the myeloproliferative disorders.

Acute leukaemia after hydroxyurea therapy in polycythaemia vera and allied disorders: prospective study of efficacy and leukaemogenicity with therapeutic implications

Fifty consecutive patients, 30 of whom had polycythaemia vera (PV), 10 essential thrombocythaemia (ET), and 10 myelofibrosis (MF), entered a long-term prospective study of hydroxyurea (HU) therapy. The indication for treatment was mainly thrombocytosis or symptomatic splenomegaly. Control of erythrocytosis and thrombocytosis was achieved in 70% of the patients. Continuous maintenance treatment was required. In 15% of responding patients with thrombocytosis, unexpected rises of the platelet count occurred during maintenance therapy. Severe thrombo-embolic events occurred in 6 patients. The size of the spleen decreased in all patients who did not develop thrombocytopenia and could absorb adequate HU doses. Acute leukaemia (AL) was diagnosed in 9 patients and a myelodysplastic syndrome in one. Seven of them had been treated with HU alone. Among the patients with PV and ET, 6 developed AL and 4 of them were treated with HU alone (3 PV and 1 ET), giving an incidence of 10.5%. In previously untreated patients with initially normal karyotypes (n = 19), chromosome abnormalities developed during HU therapy in 7 (37%). Our results indicate that HU should be regarded as leukaemogenic, at least when used for treatment of PV and allied diseases. Since myelosuppressive treatment of PV does not prolong survival, the use of HU should be restricted to patients in whom the treatment indication outweights the risk of leukaemia induction.

Prevalence of iron deficiency in Swedish adolescents

The prevalence of iron deficiency was determined in Göteborg, Sweden, in a sample of 15- to 16-y-old girls (n = 220) and boys (n = 207) using serum ferritin (SF). In a recent study in women on the relationship between SF and stainable bone marrow iron, it was established that at a cutoff value for SF of < 16 micrograms/L in 75% of women with no iron stores SF concentration was below this value (sensitivity 75%), whereas in 98% of iron-replete women it was above this cutoff value (specificity 98%). The present study showed that in 40% of the girls and 15% of the boys SF was below this cutoff value, indicating iron deficiency. Low SF concentration was associated with significant decreases in transferrin saturation, Hb concentration, mean corpuscular Hb, and mean corpuscular volume. The results from this cross-sectional study showed that, with decreasing SF, the decrease of values for these parameters occurred already before SF had reached the level 16 micrograms/L, suggesting that SF can be validly used as a single criterion of iron deficiency. Using the cutoff value SF < 16 micrograms/L, the figures for the prevalence of iron deficiency in adolescents in different countries were compared and found to be rather similar in Australia, Canada, the United States, and Sweden. High iron requirements combined with the present low-energy life-style leading to an insufficient supply of dietary iron may be a reasonable main explanation for the paradoxical, high prevalence of iron deficiency in adolescents in affluent societies.

Variable growth in vitro of chromosomally different stem cells in myelodysplastic syndromes

Ten patients with myelodysplastic syndromes were investigated using in vitro colony assay of bone marrow cells and chromosome analysis of single colonies. The result was compared with conventional cytogenetic analysis of bone marrow cells. The chromosome abnormalities included were 5q-, +8, -7, 11q-, -Y and one complex karyotype. Erythroid colony formation was reduced in eight patients, while the number of granulocyte-macrophage colony-forming units was normal or increased. Cytogenetic examination of single colonies showed that both chromosomally normal and abnormal stem cells had colony forming ability. The proportion of cytogenetically abnormal colonies varied between 25 and 100% of analysed colonies. No further clones than those found in direct cytogenetic analysis were revealed after in vitro growth. One patient with a 5q- abnormality and one patient with a -7 abnormality showed a significantly lower proportion of cytogenetically abnormal colonies than the proportion of abnormal cells in the direct bone marrow chromosome preparation. One patient with a +8 abnormality showed a growth advantage of the +8 clone in comparison with the chromosomally normal clones, but this was not statistically significant. In two patients a chromosomally changed stem cell gave rise to both erythroid and myeloid colonies. The FAB-class did not seem to influence the growth of either chromosomally normal or abnormal colonies.

Dysplastic megakaryopoiesis with thrombocytopenia and chromosomal aberration

A case of isolated thrombocytopenia with decreased platelet production and abnormal megakaryopoiesis is described. In the bone marrow, a chromosomally aberrant clone, 45,XX,-11,-18,+der (11;18)(11q13;18p11), was found. These findings indicate a myelodysplastic nature of the abnormal thrombocytopoiesis. The described case demonstrates the value of a bone marrow examination including histopathology with immunologic techniques to evaluate the megakaryopoiesis in thrombocytopenia and the interest of cytogenetic studies not only in instances with overt hematologic malignancies or complete myelodysplastic syndromes, but also when morphologic abnormalities occur in a single cell line.

Rapid decline of chronic myeloid leukemic cells in long-term culture due to a defect at the leukemic stem cell level

In this report we describe a quantitative in vitro assay for the most primitive type of leukemic precursors yet defined in patients with chronic myeloid leukemia (CML). This assay is based on the recently described "long-term culture-initiating cell" (LTC-IC) assay for primitive normal human hematopoietic cells. Such cells, when cocultured with competent fibroblast feeder layers, give rise after a minimum of 5 weeks to multiple single and multilineage clonogenic progenitors detectable in secondary semisolid assay cultures. Similar cultures initiated by seeding a highly enriched source of leukemic cells from patients onto normal feeders showed the clonogenic cell output after 5 weeks to be linearly related to the input innoculum over a wide range down to limiting numbers of input cells, thus allowing absolute frequencies of leukemic LTC-ICs to be determined using standard limiting dilution analysis techniques. Leukemic LTC-IC concentrations in CML marrow were found to be decreased, on average to less than 10% of the normal LTC-IC concentration in normal marrow, but were greatly increased (up to greater than 10(5) times) in CML blood. Assessment of the number of clonogenic cells produced per leukemic LTC-IC by comparison to normal blood or marrow LTC-IC values showed this function to be unchanged in leukemic LTC-ICs [i.e., 3.1 +/- 0.4 clonogenic cells per CML LTC-IC (mean +/- SEM, n = 6) versus 3.7 +/- 1.2 (n = 3) and 4.3 +/- 0.4 (n = 5), respectively, for normal blood and marrow LTC-ICs]. In contrast, leukemic LTC-IC maintenance in LTC proved to be highly defective by comparison to normal LTC-IC of either blood or marrow origin. Thus, when cells from primary LTC were subcultured into secondary LTC-IC assays, leukemic LTC-IC rapidly declined (greater than 30-fold) within the first 10 days of culture, whereas normal LTC-IC numbers remained unchanged during this period. These findings illustrate how self-maintenance and differentiation events in primitive human hematopoietic cells can be differentially modulated by an oncogenic process and provide a framework for further studies of their manipulation, analysis, and therapeutic exploitation.

Cytogenetic abnormalities in acute leukemia complicating melphalan-treated multiple myeloma

The cytogenetic findings in 11 patients with multiple myeloma in whom a myelodysplastic syndrome or an acute nonlymphocytic leukemia developed are reported. All patients were treated with oral melphalan for 2-9 years in a total dose of 0.5-4.1 g. When examined during the myelodysplastic or leukemic phase, all patients had an abnormal bone marrow karyotype, hypodiploid in nine of the 11 cases. The chromosome abnormalities were clearly nonrandom and comprised a 5q deletion in three cases, monosomy 5 in four cases, deletion 7q--in two cases, and monosomy 7 in three cases. Loss of material from the long arm of chromosomes 5, 7, or both was found in eight patients. The different chromosome abnormalities were not associated with any specific morphological or clinical features.

Bone marrow in vitro growth and cytogenetic studies in patients with FAB-classified primary myelodysplastic syndromes

Thirty-eight consecutive patients with a FAB-classified primary myelodysplastic syndrome (MDS) were investigated for in vitro growth of colony-forming units for granulocyte-macrophage precursors (CFU-GM) and cytogenetic analysis of bone marrow cells. Abnormal CFU-GM growth was found in 30 patients (79%), and clonal chromosome abnormalities were found in 13 patients (34%). The eight patients who showed normal CFU-GM growth were either cytogenetically normal (n = 5), or had a 5q-deletion (n = 3) as single or dominating karyotypic abnormality. Among the 30 patients with reduced or no colony growth, ten patients had a clonal chromosome abnormality. Leukemia developed in eight patients. None of them grew any CFU-GM colonies, and three of them were cytogenetically abnormal at the time of diagnosis of MDS. Analysis of the bone marrow in vitro growth for CFU-GM and the karyotype in patients with MDS emphasizes the close relationship between these disorders and manifest acute leukemia. Subgroups of MDS may be defined by a cytogenetic classification (e.g., the 5q-syndrome), and the CFU-GM growth pattern can be of value for predicting leukemic transformation.

Recombinant interferon-alpha-2b treatment of hairy-cell leukaemia: experience with a low-dose schedule

50 patients with hairy cell leukaemia (HCL) were treated with recombinant interferon (IFN) alpha-2b 2.0 x 10(6) IU/m2 subcutaneously three times weekly to evaluate the efficacy of low-dose IFN therapy in inducing and maintaining remission of the disease. At the time of this report 48 patients, of whom 22 were splenectomized, had been treated for at least 3 months and were considered evaluable for response. The median observation time on IFN-alpha-2b was 11 months (range 3 to 20). 4 cases with atypical disease (spongy lymphoid myelofibrosis) were also included. All patients responded to IFN. After 3 months 11/48 patients (23%) had achieved a partial remission (PR) with normalization of peripheral blood values. After 6 months 27/43 patients (63%) had achieved a favourable response; complete remission (CR) was recorded in 4 and PR in 23 patients. The proportion of patients with favourable responses (CR + PR) increased with the duration of therapy and after 12 months of therapy 23/28 (82%) patients showed CR or PR, 9 patients (32%) being in CR. Splenectomized patients disclosed a trend towards a more rapid response. It is concluded that IFN-alpha-2b is a highly effective first-line therapy for HCL.

A prospective long-term cytogenetic study in polycythemia vera in relation to treatment and clinical course

This paper reports the results of cytogenetic studies in a consecutive series of 64 patients with polycythemia vera, 57 of whom could be followed prospectively. The median length of the cytogenetic observation time was 93 months (range, 24 to 224 months) after diagnosis. Clonal chromosome abnormalities were observed initially in 11 patients (17%) and later during the course of the disease in another 20 patients. An abnormal karyotype was found in 71% to 80% of the patients who were examined after the development of myeloid metaplasia, myelofibrosis, or leukemia. Patients treated with myelosuppressive agents showed a significantly greater risk of chromosome abnormalities developing than did patients who had been phlebotomized. Acute leukemia developed in eight patients, all of whom had been treated with myelosuppressive agents. A chromosome abnormality preceded the leukemia in only two of the patients. The initial presence of an abnormal karyotype did not predict a greater risk of development of leukemia. No consistent relationship was demonstrated between the occurrence of chromosome abnormalities and the development of myeloid metaplasia and/or myelofibrosis, which was observed in 42% of the patients. The chromosome abnormalities followed a nonrandom pattern, and those most frequently observed were trisomies for 1 q, 8, 9, or 9p and deletion of 20q. Deletions seem to be common and were found in 14 patients.

Cytogenetic studies and in vitro colony growth in patients with mastocytosis

Cytogenetic analysis of bone marrow cells and in vitro growth for bone marrow granulocytic-macrophage stem cells have been performed in 13 patients with mastocytosis, six with systemic mastocytosis, and seven with urticaria pigmentosa. Clones with chromosome abnormalities were found in five patients. The number of clusters and/or colonies after seven days in culture was increased in seven patients, compared with the growth in a control group. Three patients with chromosome abnormalities showed an abnormal growth pattern, yet exhibited normal peripheral blood values. Two patients with systemic mastocytosis had clones with chromosome abnormalities and some abnormal hematological values. The proportion of patients with chromosome abnormalities and an abnormal growth pattern was higher among these patients with mastocytosis than in healthy control subjects. These results may be of interest when discussing the origin of mast cell disorders and indicate an association with the myeloproliferative disorders.

Cyanocobalamin absorption in the elderly: results for healthy subjects and for subjects with low serum cobalamin concentration

We examined the intestinal absorption of cyano[57Co]cobalamin from a non-protein-bound test dose given to 38 subjects from a population of elderly. The subjects were 76 years old and were apparently free from conditions known to affect cyanocobalamin absorption. Their gastric mucosal function was normal, as judged from determinations of serum gastrin and pepsinogen I. The urinary excretion of radioactivity during the first 24 h was 24(SD 7)%, range 8.6 to 45.2%, corresponding to a health-associated reference interval of 10 to 38%. The results indicate that cyanocobalamin absorption does not decline during normal aging. Duplicate studies were performed in another 20 subjects (70-81 years old) from the same population study; these subjects had a serum cobalamin concentration less than 130 pmol/L. The imprecision (CV) was 23%.

Cyanocobalamin absorption in the elderly: results for healthy subjects and for subjects with low serum cobalamin concentration

We examined the intestinal absorption of cyano[57Co]cobalamin from a non-protein-bound test dose given to 38 subjects from a population of elderly. The subjects were 76 years old and were apparently free from conditions known to affect cyanocobalamin absorption. Their gastric mucosal function was normal, as judged from determinations of serum gastrin and pepsinogen I. The urinary excretion of radioactivity during the first 24 h was 24(SD 7)%, range 8.6 to 45.2%, corresponding to a health-associated reference interval of 10 to 38%. The results indicate that cyanocobalamin absorption does not decline during normal aging. Duplicate studies were performed in another 20 subjects (70-81 years old) from the same population study; these subjects had a serum cobalamin concentration less than 130 pmol/L. The imprecision (CV) was 23%.

Trisomy 1q in polycythemia vera and its relation to disease transition

Clinical and cytogenetic details of 12 patients with polycythemia vera and complete or partial trisomy of the long arm of chromosome 1 are reported. All patients had trisomy for at least the segments 1q22 to 1qter. The 1q or material from 1q was translocated to another chromosome in eight patients. This was chromosome 9 in four patients, and those cases all had trisomy also for 9p. The trisomy 1q was found at the time of diagnosis in three patients, later during the polycythemic phase in five, and in four patients when they were first examined during a late stage of the disease. Acute leukemia or a myelodysplastic syndrome developed in eight of the 12 patients. Signs of advanced disease, eg, myeloid metaplasia or myelofibrosis, preceded the leukemia in four cases and was noted in one more patient. Trisomy 1q was the most frequent structural chromosome abnormality in patients with polycythemia vera. It is thus one of several nonrandom abnormalities that can appear at any stage of the disease. It seems to occur with higher frequency in patients with myelofibrosis and/or leukemia, but it is not a specific characteristic of these complications.

The bone marrow in urticaria pigmentosa and systemic mastocytosis. Cell composition and mast cell density in relation to urinary excretion of tele-methylimidazoleacetic acid

The bone marrow sections from five normal subjects and 18 patients with mastocytosis were examined to establish criteria to distinguish urticaria pigmentosa from systemic mastocytosis. Nine patients had increased numbers of mast cells in bone marrow sections stained with a long toluidine blue staining technique specific for mast cells, whereas five patients exhibited increased numbers of mast cells on May-Grünwald-Giemsa-stained smears of bone marrow. A positive correlation between the number of mast cells in sections of the bone marrow and the urinary excretion of the main histamine metabolite tele-methylimidazoleacetic acid was found. In ten of the examined bone marrow specimens, focal lesions containing mast cells, lymphocytes, and eosinophils appeared. The presence of these focal lesions together with either an increased number of mast cells in bone marrow sections and/or increased urinary excretion of telemethylimidazoleacetic acid is considered diagnostic of systemic mastocytosis. No patient exhibited myeloproliferative condition or other major hematologic abnormality.

Karyotypic evolution in Ph-positive chronic myeloid leukemia in relation to management and disease progression

In a prospective study of 32 patients with chronic myeloid leukemia the frequency of chromosome abnormalities in addition to the Philadelphia chromosome (Ph) increased when the disease progressed. Before metamorphosis, 10 patients (31%) had developed additional abnormalities. Such abnormalities were present in three of them at the time of diagnosis; in the other seven, they were detected late in the chronic phase. New clonal abnormalities heralded or accompanied a more malignant phase of the disorder, usually a blastic leukemia. During metamorphosis, 78% of the patients had additional abnormalities, which in 68% of these cases comprised at least one of +8, +22q- or i(17q). Clones with additional abnormalities disappeared in eight cases, either spontaneously or in association with cytostatic therapy during the chronic or blastic phase. Involvement of chromosome #8, usually in the form of a trisomy, was found in 7 of 12 patients treated with busulfan, but was not found in any of the 10 hydroxyurea-treated patients, of whom 8 were splenectomized early during the chronic phase. Cells from the spleen, obtained by fine needle aspiration or splenectomy were cytogenetically examined in 18 cases during the chronic phase, but abnormalities in addition to the Ph were noted in only one patient, who was examined in the late chronic phase. The same abnormalities were present in bone marrow cells of this patient.

Vitamin B12 in plasma in patients with continent ileostomy and long observation time

Plasma cobalamins (vitamin B12) were determined by a microbiological method in 235 patients with continent ileostomies and postoperative observation times of 3-13 years (mean, 6 years). The influence of the reservoir on the vitamin B12 values could not be evaluated in 22 patients (9%)--because of prophylactic treatment in 6%, subnormal B12 values before the operation in 1%, and 'treatment' of various neurological symptoms not caused by vitamin B12 deficiency in 2%. Fourteen (7%) of the remaining 213 patients had developed subnormal plasma levels of vitamin B12 and another 14 patients (7%) had 'borderline' values (130-200 pmol/l). The median time interval between reservoir operation and the development of subnormal values was 7.5 years (range, 3-11 years). A small-bowel resection had been added to the proctocolectomy in 11 out of 14 patients with subnormal values and in 8 out of 14 patients with borderline values. Subnormal or borderline values were seen in 27% of patients with Crohn's disease and in 12% of patients with ulcerative colitis. No patient had anaemia or neurological symptoms caused by B12 deficiency. The study shows that most patients with continent ileostomies do not develop B12 deficiency, and there is therefore no need for general prophylaxis. Since at least 7% developed subnormal values, the plasma levels of vitamin B12 should, however, be followed up regularly in all patients with continent ileostomies.

Conventional malabsorption tests: do they detect the adult patient with villous atrophy?

A total number of 134 patients with subtotal or partial villous atrophy, of whom 49 had dermatitis herpetiformis, were investigated with blood folate assay and xylose and lactose absorption tests. Faecal fat excretion was determined in 71 patients without dermatitis herpetiformis (coeliac group). A comparison was made between three patient groups, the patients with dermatitis herpetiformis and the coeliac patients studied in 1970-74 and 1975-79, respectively. From clinical and biochemical analyses of these patients we conclude that although a combination of the four malabsorption tests used here still detect a majority of coeliac patients, small intestinal biopsy may reveal villous atrophy also in patients without any laboratory evidence for malabsorption by these commonly used tests. In dermatitis herpetiformis, however, the sensitivity of the tests used was low; these malabsorption tests therefore have little diagnostic value in this category of patients.

Cytogenetic studies of bone marrow and extramedullary tissues and clinical course during metamorphosis of chronic myelocytic leukemia

Of 33 consecutive patients with chronic myelocytic leukemia, examined during metamorphosis, 82% showed chromosome abnormalities in addition to the Ph1. Aberrations most frequently encountered were +8 (39%), +22q - (30%), and i(17q) (18%). Translocations other than the Ph1 were observed in four cases and - Y clones in four cases. Discrepancies in the cytogenetic pattern between bone marrow and extramedullary tissues or blood were noted in a total of 15 patients. In six cases, transformation occurred in extramedullary organs at a time when it was not present in the marrow. In three cases the bone marrow transformation was preceded by a lymph node blastic infiltrate; in one case, by a skin infiltrate; and in one case, by a subdural blastoma. Clonal abnormalities additional to the Ph1 were identified in the tumor tissue from all these cases. Patients with primary extramedullary transformation tended to have a lower median age at onset of metamorphosis, shorter survival, and higher incidence of chromosome abnormalities than the cases without extramedullary involvement. Patients with only Ph1-positive cells and no other anomalies had a slightly longer duration of metamorphosis and longer total survival. Basophilia and thrombocytopenia were more marked in cases with i(17q) than in the rest of the series.

The relation of platelet kinetics to bone marrow megakaryocytes in chronic granulocytic leukaemia

The relation of thrombokinetics to quantitative determinations of megakaryocytes (mgkc) in bone marrow sections was studied in 11 consecutive cases of untreated Ph1-positive chronic granulocytic leukaemia (CGL). The results were compared with controls and with previously obtained data in polycythaemia vera (PV), primary thrombocythaemia (PT) and in idiopathic thrombocytopenic purpura (ITP). Platelet survival was significantly reduced in CGL. Platelet production was 5.8 x normal and the mgkc number and volume/microliter bone marrow were significantly increased as compared to controls. The increase in mgkc volume was not in proportion to that of number due to a significant decrease of mgkc size. Platelet production was strongly related to mgkc number/mm2 and to the mgkc volume/microliter bone marrow. The platelet production rate in relation to a unit of mgkc volume/microliter bone marrow was, however, greater in CGL than in controls, PV, PT and ITP. The chief reason for this is most probably the greater expansion of the total bone marrow mass in CGL.

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.

On the 5q- deletion: clinical and cytogenetic observations in ten patients and review of the literature

Clinical and cytogenetic findings in 10 patients with deletions of the long arm of chromosomes 5 (5q-) are reported. Five cases had refractory anemia, the preleukemic syndrome, or refractory anemia with an excess of blasts; in all but one, the 5q- was the single initial abnormality. Three patients had overt leukemia; in all, the 5q- was accompanied by additional anomalies. Two patients had a myeloproliferative disorder. In one of these, a case of polycythemia vera, the 5q- appeared secondarily to other karyotypic abnormalities and concomitantly with transformation into a "spent phase." The deletions were interstitial in most cases, and even if the size of the deletion varied, the region q15-q31 was lost in all cases except 2. Bone marrow from all cases except one showed a marked increase in the number of megakaryocytes. A survey of the literature yielded a total of 69 evaluable patients with 5q- deletions, including the present series. The 5q- has now been observed in a wide spectrum of hematologic disorders. However, most cases had either preleukemia (39%) or leukemia (46%). When detected during preleukemia, the 5q- usually appeared alone (74%), while during overt leukemia it regularly was accompanied by other abnormalities (88%).

Polycythaemia vera terminating in acute leukaemia. A clinical, cytogenetic and morphologic study in 8 patients treated with alkylating agents

A total of 120 patients with polycythaemia vera (PV) were observed between 1971-1976. 8 of them developed acute leukaemia (AL). The clinical course, cytogenetic and morphologic findings of these patients are described in detail. Alkylating agents were the main treatment for all patients who developed AL. 4 of them obtained alkylating drugs alone. Deaths in AL constituted 36% of the deaths observed in the groups treated with alkylating agents and 23% of the total number of deaths in these series. All patients who developed AL had active disease but they had no distinctive features predicting a malignant development. The time interval between PV diagnosis and development of AL was relatively short for those patients who were induced and maintained with alkylating agents alone. It is remarkable that 3 out of 8 patients had erythroleukaemia. Cytogenetic pretreatment studies were performed in 3 patients and all were normal. 7 patients were studied with banding techniques during the leukaemic state and all but one have shown multiple and complex abnormalities indicating several super-imposed cell lines. It seems probable that PV patients treated with alkylating agents for remission induction and maintenance may run even a greater risk for AL development than those treated with 32P.

Ph1-negative eosinophilic leukaemia with trisomy 8. Case report and review of cytogenetic studies

A case of eosinophilic leukaemia of the mature cell type in a 73-year-old man is described. Bone marrow chromosomes were studied in direct preparations on 3 occasions. With the G- and Q-banding techniques an extra chromosome number 8 was observed in all metaphases. There was no Ph1-chromosome. Therapy with vincristine and prednisone produced remissions but the course of the disease was accelerated. Review of the literature and study of the present case suggests that eosinophilic leukaemia like CGL may be divided into a Ph1-positive and a Ph1-negative group. In both groups karyotype abnormalities may be present and might herald a downhill course.