Search

ABSTRACTHereditary hemochromatosis is a genetically heterogeneous disease. Common HFE mutations (C282Y and H63D) are related to the majority of hereditary hemochromatosis cases in populations of Northern European ancestry (HFE1). Juvenile hemochromatosis (JH) is a more severe iron overload disorder, usually presenting at the second decade of life. The gene responsible for JH lies on a genetic locus at chromosome 1q. We have performed a genetic linkage study in three families of Northern Greek origin with typical clinical features of JH. In two families results were in accordance with linkage to chromosome 1q. In one family linkage of the disease to the genetic loci at 1q21, 7q22, and 6p22 was excluded. We suggest that more than one gene may underlie the JH phenotype. This genetic type of hemochromatosis may be designated 1q unlinked juvenile hemochromatosis. Family studies are necessary to establish the genetic diagnosis of JH. [Copyright &y& Elsevier]

Sickle cell disease is an inherited autosomal recessive disorder of the beta-globin chain. In Palestine it is accompanied by a low level of Hb F (mean 5.14%) and a severe clinical presentation. In this study, 59 Palestinian patients, homozygotes for Hb S were studied for their haplotype background. Eight polymorphic sites in the beta-globin gene cluster were examined. The Benin haplotype was predominant with a frequency of 88.1%, followed by a frequency of 5.1% for the Bantu haplotype. One chromosome was found to carry the Cameroon haplotype (0.85%). Three atypical haplotypes were also found (5.95%). Heterogeneity was observed in Hb F production, ranging between 1.5 and 17.0%, whereas the (G)gamma ratio was homogeneous among all haplotypes with a normal amount of about 41%. Our results are in agreement with previous reports of the Benin haplotype origin in the Mediterranean.

Mutations in the SLC40A1 gene result in a dominant genetic disorder [ferroportin disease; hereditary hemochromatosis type (HH) IV], characterized by iron overload with two different clinical manifestations, normal transferrin saturation with macrophage iron accumulation (the most prevalent type) or high transferrin saturation with hepatocyte iron accumulation (classical hemochromatosis phenotype). In previous studies, the mutational analysis of SLC40A1 gene has been performed at the genomic DNA level by PCR amplification and direct sequencing of all coding regions and flanking intron-exon boundaries (usually in 9 PCR reactions). In this study, we analyzed the SLC40A1 gene at the mRNA level, in two RT-PCR reactions, followed by direct sequencing and/or NIRCA (non-isotopic RNase cleavage assay). This protocol turned out to be rapid, sensitive and reliable, facilitating the detection of the SLC40A1 gene mutations in two patients with hyperferritinemia, normal transferrin saturation and iron accumulation predominantly in macrophages and Kupffer cells. The first one displayed the well-described alteration V162 Delta and the second a novel mutation (R178G) that was further detected in two relatives in a pedigree analysis. The proposed procedure would facilitate the wide-range molecular analysis of the SLC40A1 gene, contributing to better understanding the pathogenesis of the ferroportin disease.

The aim of the study was to evaluate the role of hypochromic erythrocytes (HYPO%) compared to "traditional" and novel markers of iron status and erythropoiesis in recognizing iron-restricted erythropoiesis (IRE) and predicting response to erythropoietin (rHuEPO) in anemic patients with myeloma and lymphoma. Forty-one newly diagnosed patients who received epoetin-beta at a subcutaneous weekly dose of 30,000 IU for 6 weeks were studied. Response to rHuEPO was observed in 27 patients (65.8%). Twelve non-responders received, additionally, 200 mg of IV iron sucrose, weekly, for 4 weeks. Evaluation of markers was performed at baseline and on weeks 1, 2 and 6 for all patients and also on weeks 7-10 for non-responders to rHuEPO. Baseline HYPO%, at a cut-off value of <5%, and an increment in reticulocyte absolute number (RETICS-AB) >or= 50,000/microl and reticulocyte hematocrit (RETICS-Hct) >or= 50%, between baseline and week 2, were independent predictive factors for response to rHuEPO. We found that these markers had superior predictive value for response to rHuEPO than four widely used predictive models. Furthermore, a baseline HYPO% count of above 5% proved superior over serum ferritin < 100 ng/ml and transferrin saturation < 20% in recognizing IRE. In conclusion, baseline HYPO% either alone or in combination with RETICS-AB or RETICS-Hct after 2 weeks of rHuEPO treatment could be reliably used in predicting response to rHuEPO. Additionally, HYPO% has proved a reliable marker for recognizing IRE before rHuEPO treatment and, thus, could be used for identifying patients who will benefit from IV iron supplementation.

The purpose of this study was to evaluate the sTfR-F index and hypochromic erythrocytes (HYPO%) as potential predictors of response to recombinant human erythropoietin (r-HuEPO) of anemic patients with multiple myeloma (MM) before treatment, as well as early in the course of treatment. Twenty-six newly diagnosed anemic MM patients received r-HuEPO 30,000 IU/wk sc, for six weeks. The sTfR-F index and HYPO% were determined at baseline and at weeks 2 and 6. Patients were classified in 1 of 4 categories of a diagnostic plot, according to erythropoietic state (ES I-IV), defined by the combination of sTfR-F index and HYPO%. Sixteen of 20 patients in ES I and II before treatment responded to r-HuEPO, whereas none of the 6 patients in ES III and IV responded (P < .001). At week 2, 44% of patients who responded and 60% of the nonresponders were in functional iron deficiency (FID) and the proportion increased to 69% and 80%, respectively, by week 6. Seven of the patients who did not respond received in addition 200 mg iron sucrose IV weekly, for the next 4 weeks, and 6 of them responded. These results suggest that combination of sTfR-F index and HYPO% in a diagnostic plot can be used as a predictive model to recognize patients who will benefit from r-HuEPO and identify FID requiring iron supplementation, before treatment and early in the course of treatment, contributing thus to optimization of r-HuEPO therapy.

Juvenile hemochromatosis is an early-onset autosomal recessive disorder of iron overload resulting in cardiomyopathy, diabetes and hypogonadism that presents in the teens and early 20s (refs. 1,2). Juvenile hemochromatosis has previously been linked to the centromeric region of chromosome 1q (refs. 3-6), a region that is incomplete in the human genome assembly. Here we report the positional cloning of the locus associated with juvenile hemochromatosis and the identification of a new gene crucial to iron metabolism. We finely mapped the recombinant interval in families of Greek descent and identified multiple deleterious mutations in a transcription unit of previously unknown function (LOC148738), now called HFE2, whose protein product we call hemojuvelin. Analysis of Greek, Canadian and French families indicated that one mutation, the amino acid substitution G320V, was observed in all three populations and accounted for two-thirds of the mutations found. HFE2 transcript expression was restricted to liver, heart and skeletal muscle, similar to that of hepcidin, a key protein implicated in iron metabolism. Urinary hepcidin levels were depressed in individuals with juvenile hemochromatosis, suggesting that hemojuvelin is probably not the hepcidin receptor. Rather, HFE2 seems to modulate hepcidin expression.

Animal models indicate that the antimicrobial peptide hepcidin (HAMP; OMIM 606464) is probably a key regulator of iron absorption in mammals. Here we report the identification of two mutations (93delG and 166C-->T) in HAMP on 19q13 in two families with a new type of juvenile hemochromatosis.

Iron overload may predominantly involve parenchymal or reticuloendothelial cells, the prototype of parenchymal iron overload being HFE-related genetic haemochromatosis. We studied a family with autosomal dominant hyperferritinaemia in whom the proband showed selective iron accumulation in the Kupffer cells on liver biopsy. Analysis of L and H ferritin genes excluded mutations responsible for hereditary hyperferritinaemia/cataract syndrome or similar translational disorders. Sequence analysis of the ferroportin gene (SLC11A3) in four individuals with hyperferritinaemia singled out a three base pair deletion in a region that contains four TTG repeats. This mutation removes a TTG unit from 780 to 791, and predicts the loss of one of three sequential valine residues 160-162. Denaturing high performance liquid chromatography can be used for its detection. SLC11A3 polymorphism analysis indicates that this probably represents a recurrent mutation due to slippage mispairing. Affected individuals may show marginally low serum iron and transferrin saturation, and young women may have marginally low haemoglobin concentration levels. Serum ferritin levels are directly related to age, but are 10-20 times higher than normal. Heterozygosity for the ferroportin Val 162 deletion represents the prototype of selective reticuloendothelial iron overload, and should be taken into account in the differential diagnosis of hereditary or congenital hyperferritinaemias.

We report the ex vivo effect of recombinant activated factor VII (rFVIIa) on prothrombin activation after whole blood clotting. Two patients with severe thrombocytopenia and life-threatening haemorrhage were successfully managed using a single dose of rFVIIa (90 microg/kg). Western blotting using antiprothrombin antibody showed that rFVIIa did not induce thrombin generation in citrated platelet-poor plasma. Patient sera showed significantly impaired prothrombin activation before and after rFVIIa administration. rFVIIa administration shortened the prothrombin time, activated partial thromboplastin time and Ivy bleeding time, and normalized the clot retraction. These data indicate that rFVIIa accelerated thrombin generation without significant increase of generated thrombin.

Purpose: Waldenström's macroglobulinemia (WM) is a low-grade lymphoplasmacytic lymphoma in which CD20 is usually expressed on tumor cells. There is evidence that patients with WM may benefit from treatment with the anti-CD20 monoclonal antibody rituximab. We performed a prospective phase II study to clearly define the activity of rituximab in patients with this disease., Patients and Methods: Twenty-seven patients with WM were treated with rituximab 375 mg/m(2) intravenously (IV) for 4 weeks. Three months after completion of rituximab, patients without evidence of progressive disease received repeat 4-week courses of this agent. All patients were symptomatic, their median age was 72 years, and 15 patients were previously untreated., Results: Twelve patients (44%; 95% confidence interval, 25.5% to 64.7%) achieved a partial response after treatment with rituximab. Median time to response was 3.3 months (range, 2.2 to 7.1 months). Responses occurred in six (40%) of 15 previously untreated patients and in six (50%) of 12 pretreated patients. Patients with a serum immunoglobulin M less than 40 g/L had a significantly higher response rate. The median time to progression for all patients was 16 months, and with a median follow-up of 15.7 months, nine of 12 responding patients remain free of progression. Treatment with rituximab was well tolerated, with approximately one fourth of patients experiencing some mild form of infusion-related toxicity, usually fever and chills., Conclusion: Our prospective data indicate that rituximab is well tolerated and active in patients with WM. Previously untreated and pretreated patients seem to benefit equally. Repeat 4-week courses of rituximab may prolong the duration of response of the disease, but this observation requires confirmation in prospective, randomized trials. Furthermore, studies that will combine rituximab with chemotherapy may be relevant.

We report two patients with severe thrombocytopenia and life-threatening bleeding that were successfully managed with recombinant activated factor VII (rFVIIa). The first was a 75-year-old male with Waldenström's macroglobulinemia. During a therapeutic course with fludarabine, he developed severe autoimmune thrombocytopenia resistant to conventional treatment, followed by persistent uncontrollable nasal bleeding. Platelet transfusions failed to increase the platelet count and control the hemorrhage. When hemoglobin levels fell below 8.5 g/dL and the patient's clinical condition got much worse, a single dose of 4.8 mg rFVIIa (90 microg/kg) was given as an i.v. bolus. Ten minutes after the rFVIIa injection, nasal bleeding stopped, the patient's clinical condition progressively improved, and splenectomy could be carried out uneventfully 2 days later. The second patient, a 52-year-old female, was under treatment for pre-B lymphoblastic leukemia. She developed severe thrombocytopenia, secondary to chemotherapy, complicated by massive gastrointestinal bleeding. Despite intensive treatment with platelet transfusions, hemorrhage continued and her condition deteriorated rapidly. She was then given an i.v. bolus injection of 4.8 mg rFVIIa, which resulted in cessation of hemorrhage and dramatic improvement of her clinical status. No adverse effects from the treatment with rFVIIa were observed. In conclusion, rFVIIa appears to be an attractive alternative for controlling hemorrhage in patients with severe thrombocytopenia, especially when platelet transfusions are unavailable or ineffective.

Various genetic abnormalities are often found in B-CLL, but their relative importance in the pathogenesis and evolution of the disease has not been adequately clarified. We studied the expression of bcl-2 protein and the possible simultaneous occurrence of bcl-2 overexpression, trisomy 12 and the Rb1 and p53 gene deletions in 38 patients with B-CLL by combining immunophenotyping and dual color interphase FISH. We also looked for correlation between the genetic abnormalities and clinical parameters such as stage, disease duration from diagnosis to the time of study and overall survival. High expression of the bcl-2 protein was found in 76.3% of the patients (29/38). Trisomy 12 was found in 37% of cases (14/38) and Rb1 monoallelic gene deletion in 42% (16/38). The percentage of cells with hemizygous Rb1 deletion ranged from 13 to 18%. Monoallelic deletion of p53 was found in 29% of cases (11/38). The number of cells with only one signal ranged from 28 to 98%. Patients in stage A had on average, less than one abnormality, while patients in stage C had 2.6 abnormalities. Patients appeared to accumulate genetic abnormalities with time. Bcl-2 overexpression was found early in the course of the disease. Trisomy 12 appeared later, at about the same time as Rb1 deletion, but was not associated with adverse prognosis. Monoallelic deletion of p53 gene appeared rather late in the course of the disease and was associated with advanced stage. Despite the fact that more deaths occurred in the group of patients with three or four abnormalities and the presence of p53 gene deletion, differences in survival were not statistically significant, probably due to the limited number of patients in each group. A larger group of patients studied in a prospective manner will better clarify these issues in the future.

beta-Thalassaemia major is a severe, transfusion-dependent anaemia that also causes infertility due to iron deposition to endocrine organs. Very few pregnancies have been reported among such patients. In this report we describe the evolution and successful outcome of pregnancy in 5 Greek women with beta-thalassaemia major. There were four full-term and one preterm deliveries of two normal and three small for the date neonates. Cardiovascular changes related to gestation may aggravate the underlying multiorgan damage of the pregnant mother and predispose to poor fetal growth and development. All five patients followed a strict transfusion regimen in order to maintain the haemoglobin level above 10 g/dl. The inadvertent administration of desferrioxamine in one patient until the 8th gestational week did not seem to have any serious effects on the development and well-being of the fetus. Although pregnancy is not contraindicated in beta-thalassaemia major, intensive individualized care is required if it is to be safe for the mother, and have a reasonably good chance of producing a healthy child.

In an attempt to estimate the prevalence of beta thal zero and beta thal+ thalassemia genes in northern Greece we analyzed hemoglobin samples of 32 subjects with sickle cell thalassemia (beta s/beta thal), from an area of northern Greece (Chalkidiki, 22-24E, 41-42N), where thalassemia and sickle cell disease are common. 24 subjects had no detectable Hb A and only 8 had Hb A ranging grossly between 3-5 per cent in six patients and 10-15 per cent in two patients. Thus the estimate of the relative frequency of the beta thal zero to the beta thal+ was found to be 0.75 +/- 0.077. For the beta thal+ gene, our findings are in agreement with all other Greek investigations in that it is associated with a low or very low presence of Hb A. As to frequencies, however, our findings differ significantly from results reported from other Greek investigators who examined mainly the population of Athens, and this may be explained by an uneven distribution of the various types of thalassemia genes in the various parts of Greece.

Study of the Hpa I polymorphism 3' to the beta-globin gene in the Greek population revealed absence of the site in 238 beta S chromosomes, in contrast to a much larger sample of chromosomes carrying the beta A gene, where this site was consistently positive. Subsequent haplotype analysis of the beta-globin gene cluster in 82 beta S chromosomes demonstrated that 79 (96%) belonged to haplotype #19, while the three exceptions (all Hpa I negative) could be explained by a delta-beta recombination event. Haplotype #19 was never encountered in a parallel study of the 83 beta A chromosomes. Comparison of the above results with similar surveys in other parts of the world and consideration of various historical events suggest that the beta S mutation was introduced into Greece over the last few centuries by the Saracen raids and/or by settlements of North African slaves brought in by the Arabs, Franks, Venetians, or Ottoman Turks, who have occupied the country over the last millennium.