Iron deficiency anaemia revisited

Iron deficiency anaemia is a global health concern affecting children, women and the elderly, whilst also being a common comorbidity in multiple medical conditions. The aetiology is variable and attributed to several risk factors decreasing iron intake and absorption or increasing demand and loss, with multiple aetiologies often coexisting in an individual patient. Although presenting symptoms may be nonspecific, there is emerging evidence on the detrimental effects of iron deficiency anaemia on clinical outcomes across several medical conditions. Increased awareness about the consequences and prevalence of iron deficiency anaemia can aid early detection and management. Diagnosis can be easily made by measurement of haemoglobin and serum ferritin levels, whilst in chronic inflammatory conditions, diagnosis may be more challenging and necessitates consideration of higher serum ferritin thresholds and evaluation of transferrin saturation. Oral and intravenous formulations of iron supplementation are available, and several patient and disease-related factors need to be considered before management decisions are made. This review provides recent updates and guidance on the diagnosis and management of iron deficiency anaemia in multiple clinical settings.

Clinical outcomes of Clostridium difficile infection according to strain type. A prospective study in medical wards

OBJECTIVES

To describe clinical characteristics and outcome of Clostridium difficile infection (CDI) patients in Internal Medicine, to identify ribotypes (RTs); to evaluate the association between RT and patient clinical characteristics and report outcome.

METHODS

One year prospective cohort study. Clinical data, Barthel Index (BI) and outcomes were collected for all inpatients suffering from CDI (n = 148) in hospital wards in Northern Italy. 84 fecal samples were analysed for molecular typing.

RESULTS

12 RTs were identified, predominantly RT018 (42.9%, n = 36/84) and RT356/607 (40.5%, n = 34/84). Patients with dementia were more frequent among those infected by RT018 [55.6% (n = 20/36) vs. 32.4% (n = 11/34), p = 0.05]. The median BI score of patients with RT018 was lower than BI score of patients with RT356/607 [10 (IQR 0-32) vs. 15 (IQR 5-50), p = 0.06]. RT018 infection was associated to higher levels of C-reactive protein [7.2 mg/dl (IQR 4.1-14.7) vs. 4.0 mg/dl (IQR 2.2-6.8), p = 0.01] and white blood cells ≥15,000/dl [33.3% (n = 12/36) vs. 14.7% (n = 5/34) of patients, p = 0.07]. Higher mortality was noted among RT018 infected patients. We found a continuous mortality increase according to the ATLAS score.

CONCLUSIONS

Our results confirm that RT018 and RT356/607 are the two major RTs causing CDI in older patients with a high degree of disability in Northern Italy and RT018 is associated with more serious outcomes.

Combined Use of DNA Probes in First-Trimester Prenatal Diagnosis of Hemophilia A

First-trimester prenatal diagnoses of hemophilia A were heretofore obtained by using either intragenic factor VIII markers or linked cxtragcnic polymorphic markers. Postulating that the combined use of all the available intragenic and extragenic markers can render such diagnoses more frequently feasible and more reliable, we carried out ten first-trimester prenatal diagnoses in male fetuses at risk for hemophilia A by DNA analysis of chorionic villus employing in combination the intragenic Bcl I polymorphism and the St 14 (DXS 52) or DX 13 (DXS 15) extragenic probes. A diagnosis of hemophilia was obtained in three fetuses, with a diagnosis of normal fetus obtained in the remaining seven. Seven diagnoses are confirmed by factor VIII assays carried out at the time of abortion, in the mid-Trimester or at birth. A factor VIII probe recognizing Bcl I polymorphism was useful in 4 of 6 diagnoses; St 14, in 5 of 6; and DX 13 in 3 of 5. In two cases, St 14 was the only useful probe for diagnosis. Even though no recombination between extragenic probes and factor VIII gene was detected in this study, when only extragenic markers were informative we advised diagnostic confirmation on fetal plasma obtained by fetoscopy. Hence, first-trimester prenatal diagnosis of hemophilia A is feasible for the great majority of fetuses at risk through combined use of all the available intragenic and extragenic probes, providing key family members are available.

Skeletal involvement in type 1 Gaucher disease: Not just bone mineral density

Gaucher disease is characterized by multi-organ infiltration of phospholipid-laden macrophages. Bone involvement is characterized by typical deformities, osteopenia/osteoporosis, pathological fractures, and bone marrow infiltration (avascular osteonecrosis, infarction). Estimation of skeletal disease includes bone quality that contributes substantially to bone strength. We studied 23 type 1 Gaucher patients (median age 22years, range 3-73) on Enzyme Replacement Therapy from 2months to 26years (median 7years); 4 patients had pathological fractures, 10 bone infarctions, 6 avascular osteonecrosis. We noninvasively assessed bone quality by trabecular microarchitecture and macroscopic geometry, using two innovative dual-energy X-ray absorptiometry tools: Trabecular Bone Score (TBS) and Hip Structural Analysis (HSA). Bone quality parameters distinguished the patients with skeletal complications. TBS was significantly lower in patients with avascular osteonecrosis (p=0.049) and pathological fractures (p=0.024), while it could not identify those with bone infarctions. Among HSA parameters, the Cross Sectional Area of the intertrochanteric region and the Buckling Ratio of the narrow neck allowed the distinction of patients with avascular osteonecrosis. BMD was low in 11 patients (50%); neither BMD nor HSA were associated with pathological fractures. The combined evaluation of bone quality and bone quantity is useful to identify GD patients with more severe skeletal involvement.

Pregnancy in patients with thalassemia major: a cohort study and conclusions for an adequate care management approach

An improvement in quality of life and survival occurred among thalassemia major (TM) patients: pregnancy in such patients has become a reality. Safe pregnancy and delivery require efforts to ensure the best outcomes. Between 2007 and 2016, 30 TM patients had 37 pregnancies. We analyzed the hematological parameters before, during, and after pregnancies and in 19 patients a cardiovascular magnetic resonance (CMR) T2* was performed. The mean age at first pregnancy was 30 ± 4 years; the current mean age is 35 ± 5 years. Twenty-four patients (80%) had a single pregnancy, five patients (17%) had two pregnancies, and one patient (3%) became pregnant three times. Seventeen pregnancies (46%) were spontaneous, 20 (64%) needed gonadotrophin-induced ovulation and/or reproductive technologies. All pregnancies resulted in live births. Seven were twin pregnancies (19%). The mean gestational hemoglobin was 9.2 ± 0.5 g/dl, lower than pre- and postpregnancy (9.8 ± 1 g/dl, p = ns and 9.6 ± 1 g/dl, p = 0.02, respectively). Median ferritin levels increased progressively (1071, range 409-5724 ng/ml, before pregnancy vs 2231, range 836-6918 ng/ml, after pregnancy, p < 0.0001). CMR before pregnancy showed a normal cardiac T2* (mean 35.34 ± 8.90 ms) and a mean liver iron concentration (LIC) of 3.37 ± 2.11 mg/g dry weight (dw). After pregnancy, the mean cardiac T2* was 31.06 ± 13.26 ms and the mean LIC was significantly increased (9.06 ± 5.75 mg/g dw, p = 0.0001). Pregnancy is possible and safe in thalassemia major. During pregnancy, iron accumulates, especially in the liver; a prompt resumption of chelation after delivery is mandatory.

Bone quality in beta-thalassemia intermedia: relationships with bone quantity and endocrine and hematologic variables

We report the first evaluation of bone quality in 70 thalassemia intermedia (TI) patients (37 males, 33 females, age 41 ± 12 years). Thirty-three patients (47%) had been transfused, 34 (49%) had been splenectomized, 39 (56%) were on iron chelation therapy, and 11 (16%) were on hydroxyurea. Mean hemoglobin was 9.2 ± 1.5 g/dl, median ferritin 537 ng/dl (range 14-4893), and mean liver iron concentration 7.6 ± 6.4 mg Fe/g dw. Fifteen patients (21%) had endocrinopathies, and 29 (41%) had vitamin D deficiency. Bone quantity (bone mineral density, BMD) and bone quality (trabecular bone score, TBS) were evaluated by densitometry. In 53/70 patients (76%), osteopathy was found (osteoporosis in 26/53, osteopenia in 27/53). BMD values were higher in the never-transfused patients and in the not-chelated group. A highly significant correlation was found between splenectomy and BMD at all the sites, with lower values in the splenectomized patients. TBS values were significantly lower in TI patients than in 65 non-thalassemic controls (1.22 vs 1.36, p < 0.01), mainly in those splenectomized and in the transfused and chelated groups (p < 0.01). TBS did not correlate with liver iron concentration values. Our data disclose the major role of non-invasive bone quality evaluation in TI patients, especially those with the worst health state, to obtain a comprehensive assessment of fracture risk. Splenectomy seems to play a major part in bone complications.

X-chromosomal inactivation directly influences the phenotypic manifestation of X-linked protoporphyria

X-linked protoporphyria (XLP), a rare erythropoietic porphyria, results from terminal exon gain-of-function mutations in the ALAS2 gene causing increased ALAS2 activity and markedly increased erythrocyte protoporphyrin levels. Patients present with severe cutaneous photosensitivity and may develop liver dysfunction. XLP was originally reported as X-linked dominant with 100% penetrance in males and females. We characterized 11 heterozygous females from six unrelated XLP families and show markedly varying phenotypic and biochemical heterogeneity, reflecting the degree of X-chromosomal inactivation of the mutant gene. ALAS2 sequencing identified the specific mutation and confirmed heterozygosity among the females. Clinical history, plasma and erythrocyte protoporphyrin levels were determined. Methylation assays of the androgen receptor and zinc-finger MYM type 3 short tandem repeat polymorphisms estimated each heterozygotes X-chromosomal inactivation pattern. Heterozygotes with equal or increased skewing, favoring expression of the wild-type allele had no clinical symptoms and only slightly increased erythrocyte protoporphyrin concentrations and/or frequency of protoporphyrin-containing peripheral blood fluorocytes. When the wild-type allele was preferentially inactivated, heterozygous females manifested the disease phenotype and had both higher erythrocyte protoporphyrin levels and circulating fluorocytes. These findings confirm that the previous dominant classification of XLP is inappropriate and genetically misleading, as the disorder is more appropriately designated XLP.

Spine bone texture assessed by trabecular bone score (TBS) to evaluate bone health in thalassemia major

Due to the increasing survival of thalassemic patients, osteopathy is a mounting clinical problem. Low bone mass alone cannot account for the high fracture risk described; impaired bone quality has been speculated but so far it cannot be demonstrated noninvasively. We studied bone quality in thalassemia major using trabecular bone score (TBS), a novel texture measurement extracted from spine dual-energy X-ray absorptiometry (DXA), proposed in postmenopausal and secondary osteoporosis as an indirect index of microarchitecture. TBS was evaluated in 124 adult thalassemics (age range 19-56 years), followed-up with optimal transfusional and therapeutical regimens, and in 65 non-thalassemic patients (22-52 years) undergoing DXA for different bone diseases. TBS was lower in thalassemic patients (1.04 ± 0.12 [range 0.80-1.30]) versus controls (1.34 ± 0.11 [1.06-1.52]) (p < 0.001), and correlated with BMD. TBS and BMD values correlated with age, indicating that thalassemia negatively affects both bone quality and quantity, especially as the patient gets older. TBS was 1.02 ± 0.11 [0.80-1.28] in the osteoporotic thalassemic patients, 1.08 ± 0.12 [0.82-1.30] in the osteopenic ones and 1.15 ± 0.10 [0.96-1.26] in those with normal BMD. No gender differences were found (males: 1.02 ± 0.13 [0.80-1.30], females 1.05 ± 0.11 [0.80-1.30]), nor between patients with and without endocrine-metabolic disorders affecting bone metabolism. Our findings from a large population with thalassemia major show that TBS is a valuable tool to assess noninvasively bone quality, and it may be related to fragility fracture risk in thalassemic osteopathy.

Ribavirin suppresses erythroid differentiation and proliferation in chronic hepatitis C patients

Combination therapy with pegylated interferon (pegIFN) plus ribavirin (RBV) is the standard of care for chronic hepatitis C. One of the major treatment-related side effects is anaemia, attributed to RBV-induced haemolysis. However, haemolysis biomarkers are not present in all patients supporting the existence of other pathogenetic mechanisms. We studied the role of RBV in inducing haemolysis and its effects on erythropoiesis. In 18 hepatitis C virus (HCV) genotype 2 patients treated with pegIFN-alpha-2a (180 mcg/week) plus RBV (800 mg/day) for 24 weeks and in 10 hepatitis B virus (HBV) patients treated with pegIFN-alpha-2a (180 mcg/week) for 48 weeks, haemolysis was assessed by serum LDH, haptoglobin and reticulocyte count. Erythropoiesis was evaluated both ex vivo, analysing the clonogenic activity of patients' erythroid progenitors, as well as in vitro adding pegIFN and RBV to liquid cultures obtained from CD34+ cells of healthy volunteers. The majority of patients developed anaemia; the week 4 mean haemoglobin decrease was greater in HCV than in HBV patients (1.7 vs 0.47 g/dL, P = 0.01). Only three HCV patients (17%) and no HBV patients showed signs of haemolysis. The 15 nonhaemolytic HCV patients and all HBV patients showed a delay in erythroid differentiation, with a reduction in colony number and a relative increase in undifferentiated colony percentage. Haemolytic HCV patients had an increase in colony number at week 4 of therapy. In vitro, erythroid cell proliferation and differentiation were inhibited by both pegIFN and RBV. Both pegIFN and RBV have an inhibitory effect on erythroid proliferation and differentiation.

Combination of deferasirox and deferoxamine in clinical practice: an alternative scheme of chelation in thalassemia major patients

The availability of three iron chelators improved the scenario of chelation therapy for transfusion-dependent thalassemia (TDT) patients, allowing tailoring of drugs according to the goals expected for each patient. The use of Deferiprone/Deferoxamine (DFP/DFO) combined in different schemes has been reported since many years. Only recently data from combination of Deferasirox/Deferoxamine (DFX/DFO) have been reported showing that it can be safe and efficacious to remove iron overload, particularly in patients who do not respond adequately to a single chelating agent. We investigated the efficacy, tolerability and safety of combined DFX/DFO in thalassemia major patients. Ten TDT patients have started DFX/DFO for different reasons: 1) lack of efficacy in removing liver/cardiac iron with monotherapy; 2) agranulocytosis on DFP; and 3) adverse events with elevated doses of monotherapies. The study design included: cardiac and hepatic T2* magnetic resonance (CMR), transient elastography evaluation (Fibroscan), biochemical evaluation, and audiometric and ocular examinations. The drugs' starting doses were: DFO 32 ± 4 mg/kg/day for 3-4 days a week and DFX 20 ± 2 mg/kg/day. Seven patients completed the one-year follow-up period. At baseline the mean pre-transfusional Hb level was 9.4 ± 0.4 g/dl, the mean iron intake was 0.40 ± 0.10mg/kg/day, the median ferritin level was 2254 ng/ml (range 644-17,681 ng/ml). Data available at 1 year showed no alteration of renal/hepatic function and no adverse events. A marked reduction in LIC (6.54 vs 11.44 mg/g dw at baseline) and in median ferritin (1346 vs 2254 ng/ml at baseline) was achieved. A concomitant reduction of non-transferrin-bound iron (NTBI) at six months was observed (2.1 ± 1.0 vs 1.7 ± 1.2 μM). An improvement in cardiac T2* values was detected (26.34 ± 15.85 vs 19.85 ± 12.06 at baseline). At 1 year an increased dose of DFX was administered (27 ± 6 mg/kg/day vs 20 ± 2 mg/kg/day at baseline, p=0.01) with a stable dose of DFO (32 ± 4 mg/kg/day). Combined or alternated DFX/DFO can be considered when monotherapy is not able to remove the iron overload or in the presence of adverse events.

Thalassemia trait and arterial thromboembolic events: a systematic review and a meta-analysis of the literature

BACKGROUND

An increased risk of venous thromboembolic events has been reported in thalassemic patients, in particular in patients with thalassemia intermedia. The association between β-thalassemia trait and atherothrombotic cardiovascular events is not well established.

METHODS

In a systematic review and meta-analysis of the literature, we evaluated the association between β-thalassemia trait and arterial cardiovascular disease. Studies were identified from the MEDLINE and EMBASE (until July 2010) electronic databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a random-effects model. Statistical heterogeneity was evaluated with the I(2) statistic.

RESULTS

Of the 354 identified articles, eight case-control studies were eligible for the analysis. β-Thalassemia trait was associated with a reduced risk of arterial cardiovascular disease (OR 0.45; 95% CI 0.45-0.60). Heterogeneity among studies was low (I(2) = 13%). The protective effect of β-thalassemia trait was confined to male patients (OR 0.39; 95% CI 0.24-0.62), and was not observed in female subjects (OR 0.89; 95% CI 0.52-1.53).

CONCLUSIONS

β-Thalassemia trait may act as a protective factor against the development of arterial cardiovascular and cerebrovascular disease in male subjects. Larger prospective studies are necessary to confirm these preliminary findings and to further investigate the mechanisms underlying this protective effect.

Splenectomy and thrombosis: the case of thalassemia intermedia

BACKGROUND

 Hypercoagulability in splenectomized patients with thalassemia intermedia (TI) has been extensively evaluated. However, clinical and laboratory characteristics of patients who eventually develop overt thromboembolic events (TEE) are poorly studied.

PATIENTS/METHODS

 Three Groups of TI patients (n=73 each) were retrospectively identified from a registry involving six centers across the Middle East and Italy: Group I, all splenectomized patients with a documented TEE; Group II, age- and sex-matched splenectomized patients without TEE; and Group III, age- and sex-matched non-splenectomized patients without TEE. Retrieved data included demographics, laboratory parameters, clinical complications, and received treatments that may influence TEE development, and reflected the period prior to TEE occurrence in Group I.

RESULTS

 The mean age of Group I patients at development of TEE was 33.1±11.7years, with a male to female ratio of 33:40. TEE were predominantly venous (95%) while four patients (5%) had documented stroke. Among studied parameters, Group I patients were more likely to have a nucleated red blood cell (NRBC) count ≥300×10(6) L(-1) , a platelet count ≥500×10(9)  L(-1) and evidence of pulmonary hypertension (PHT), or be transfusion naïve. The median time to thrombosis following splenectomy was 8years. Patients with an NRBC count ≥300×10(6) L(-1) , a platelet count ≥500×10(9) L(-1) , or who were transfusion naive also had a shorter time to thrombosis following splenectomy.

CONCLUSION

 Splenectomized TI patients who will develop TEE may be identified early on by high NRBC and platelet counts, evidence of PHT, and transfusion naivety.

Iron overload and toxicity: the hidden risk of multiple blood transfusions

BACKGROUND

The quantity of iron in body is carefully regulated, primarily by control of iron absorption, and excess total body iron can be extremely toxic. Since humans have no mechanism for elimination of excess iron, multiple transfusions of red blood cells, which are required for the management of a number of disorders, inevitably result in iron overload. Cumulative iron overload, in turn, leads to iron toxicity with organ dysfunction and damage.

MATERIALS

This review examines the relationship between iron metabolism and hematologic disorders treated with multiple transfusions, with emphasis on the diagnosis and current methods of management of iron overload and toxicity in transfusion-dependent patients. Primarily using key words, we identified and reviewed more than 100 pertinent articles in English and other languages in the Medline database plus an additional number of abstracts of presentations at recent meetings of relevant scientific associations.

RESULTS

Transfusion-dependent disorders include those characterized by decreased red blood cell production, increased red blood cell destruction, or chronic blood loss. Patients receiving chronic transfusion therapy should be screened and monitored for iron overload, yet in our opinion, this is not always done routinely. Once iron overload has been identified, it should be treated to reduce the risk of morbidity and mortality from iron toxicity, which particularly affects the liver and heart.

CONCLUSION

Increased awareness of the risks of iron overload from chronic transfusion therapy should result in greater use of interventions such as iron chelation to reduce total body iron and the risk of long-term sequelae.

Clinical, biochemical and genetic characteristics of Variegate Porphyria in Italy

Variegate Porphyria (VP) is an autosomal dominant disorder found worldwide but is rare in Italy. In this study we provide an overview of clinical, biochemical and genetic background of 33 Italian VP patients diagnosed in the last fifteen years. About 70% of patients had experienced clinical symptoms: 43.4% had photosensivity, 8.7% acute attacks and 47.8% both. Among the 33 patients, 14 different mutations were identified. Of these only 6 defects have been previously described in other countries and 8 are unique having been identified for the first time in Italy. Two of these, the c.851G>T and the c.1013C>G, were found in two and four unrelated families respectively. No mutation has been found in homozygosis and no significant correlation has been observed between specific clinical and biochemical manifestations and the type of mutation. In contrast, normal faecal protoporphyrin excretion was high predictive of silent phenotype. Normal urinary excretion of PBG and ALA, predicted absence of neurovisceral symptoms. This paper represents the first compilation of data on genotype-phenotype relation in Italian patients with VP.

Effect of hydroxyurea on extramedullary haematopoiesis in thalassaemia intermedia: case reports and literature review

Extramedullary haematopoiesis (EH) is the production of blood cell precursors outside the bone marrow that occurs in various disorders, such as thalassaemia, sickle cell anaemia, hereditary spherocytosis, polycythaemia vera, myelofibrosis and other haematological diseases. In chronic anaemia, it is a physiological response to increased erythropoietin. In some other conditions, such as myeloid metaplasia, polycythaemia vera or chronic myeloid leukaemia, EH is due to a clonal disorder of haematopoiesis that enables progenitor cells to escape from the marrow and lodge in other organs. EH usually involves the liver, spleen and lymph nodes or it can be paravertebral, intrathoracic, pelvic. It is often asymptomatic but can sometimes lead to symptomatic tumour-like masses. Treatment options are still controversial and limited, including hypertransfusion regimen, surgical treatment, radiotherapy and hydroxyurea (HU). We describe intrathoracic and symptomatic pelvic EH masses in a 48-year-old woman and intrathoracic bilateral masses causing respiratory insufficiency with pleural effusion in a 42-year-old male, both affected by thalassaemia intermedia. Both patients showed a clinical improvement with hydroxyurea therapy and occasional blood transfusions.

Deferasirox (Exjade) for the treatment of iron overload

Deferasirox is a once-daily oral iron chelator with established dose-dependent efficacy in both adult and pediatric patients with transfusional iron overload. The clinical development program has demonstrated the efficacy of deferasirox for up to 4.5 years of treatment in patients with various underlying anemias, including beta-thalassemia, myelodysplastic syndromes, sickle cell disease, aplastic anemia, and other rare anemias. In addition to reducing key indicators of total body iron levels (serum ferritin, liver iron concentration, and toxic labile plasma iron), deferasirox has also demonstrated the ability to remove cardiac iron and prevent future cardiac iron accumulation. Emerging long-term data confirm the tolerability profile of deferasirox, and data on patient compliance render deferasirox a suitable therapeutic option for patients with chronic conditions requiring ongoing iron chelation therapy. Data continue to accumulate in a wide range of patient groups, including those with non-transfusion-dependent anemias such as hereditary hemochromatosis.

Long-term experience with deferasirox (ICL670), a once-daily oral iron chelator, in the treatment of transfusional iron overload

BACKGROUND

Chronic iron overload from frequent blood transfusions to treat patients with severe anaemias leads to significant morbidity and mortality. While deferoxamine, the current standard of care, is an effective iron chelator, it requires subcutaneous infusion for 8-12 h/day, 5-7 days/week. This regimen is problematic and impacts significantly on patients' daily life.

OBJECTIVE

To evaluate the efficacy and tolerability of deferasirox, a once-daily oral iron chelator.

METHOD

To review the available data reported in peer-reviewed journals (using PubMed) and at medical conferences.

RESULTS/CONCLUSIONS

Deferasirox is effective in reducing or maintaining iron burden in patients with transfusion-dependent anaemias. As deferasirox is orally administered, the inconvenience of parenteral administration with deferasirox is avoided. Deferasirox improves patient satisfaction and is expected to improve compliance with iron chelation therapy.

Management of non-neuronopathic Gaucher disease with special reference to pregnancy, splenectomy, bisphosphonate therapy, use of biomarkers and bone disease monitoring

Enzyme replacement was introduced as treatment for non-neuronopathic Gaucher disease more than 15 years ago. To ensure the best use of this costly ultra-orphan agent, a systematic disease management approach has been proposed by an international panel; this includes the development, by consensus, of achievable treatment goals. Here we critically review these goals and monitoring guidelines and incorporate emerging experience of the disease in the therapeutic era, as well as contemporary clinical research. This review makes recommendations related specifically to the management of pregnancy; the appropriate use of splenectomy and bisphosphonate treatment; the relevance of biochemical markers to disease monitoring; and the use of semi-quantitative methods for assessing bone marrow infiltration. In addition, we identify key areas for development, including the requirement for a validated index of disease severity; the need to correlate widely used biomarkers with long-term disease outcomes, and the desirability of establishing agreed standards for monitoring of bone disease particularly in infants and children with Gaucher disease.

Glucose-6-phosphate dehydrogenase deficiency

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect, being present in more than 400 million people worldwide. The global distribution of this disorder is remarkably similar to that of malaria, lending support to the so-called malaria protection hypothesis. G6PD deficiency is an X-linked, hereditary genetic defect due to mutations in the G6PD gene, which cause functional variants with many biochemical and clinical phenotypes. About 140 mutations have been described: most are single base changes, leading to aminoacid substitutions. The most frequent clinical manifestations of G6PD deficiency are neonatal jaundice, and acute haemolytic anaemia, which is usually triggered by an exogenous agent. Some G6PD variants cause chronic haemolysis, leading to congenital non-spherocytic haemolytic anaemia. The most effective management of G6PD deficiency is to prevent haemolysis by avoiding oxidative stress. Screening programmes for the disorder are undertaken, depending on the prevalence of G6PD deficiency in a particular community.

Heparin induced thrombocytopenia: pathogenetic, clinical, diagnostic and therapeutic aspects

Heparin induced thrombocytopenia (HIT) in addition to bleeding complications are the most serious and dangerous side effects of heparin treatment. HIT remains the most common antibody-mediated, drug-induced thrombocytopenic disorder and a leading cause of morbidity and mortality. Two types of HIT are described: Type I is a transitory, slight and asymptomatic reduction of platelet count occurring during 1-2 days of therapy. HIT type II, which has an immunologic origin, is characterized by a thrombocytopenia that generally onset after the fifth day of therapy. Despite thrombocytopenia, haemorrhagic complications are very rare and HIT type II is characterized by thromboembolic complications consisting in venous and arterial thrombosis. The aim of this paper is to review new aspects of epidemiology, pathophysiology, clinical features, diagnosis and therapy of HIT type II. There is increasing evidence that platelet factor 4 (PF4) displaced from endothelial cells, heparan sulphate or directly from the platelets, binds to heparin molecule to form an immunogenic complex. The anti-heparin/PF4 IgG immune-complexes activates platelets through binding with the Fcgamma RIIa (CD32) receptor inducing endothelial lesions with thrombocytopenia and thrombosis. Cytokines are generated during this process and inflammation could play an additional role in the pathogenesis of thromboembolic manifestations. The onset of HIT type II is independent from dosage, schedule, and route of administration of heparin. A platelet count must be carried out prior to heparin therapy. Starting from the fourth day, platelet count must be carried out daily or every two days for at least 20 days of any heparin therapy regardless of the route of the drug administration. Patients undergoing orthopaedic or cardiac surgery are at higher risk for HIT type II. The diagnosis of HIT type II should be formulated on basis of clinical criteria and confirmed by in vitro demonstration of heparin-dependent antibodies detected by functional and antigen methods. However, the introduction of sensitive ELISA tests to measure anti-heparin/PF4 antibodies has showed the immuno-conversion in an higher number of patients treated with heparin such as the incidence of anti-heparin/PF4 exceeds the incidence of the disease. If HIT type II is likely, heparin must be immediately discontinued, even in absence of certain diagnosis of HIT type II, and an alternative anticoagulant therapy must be started followed by oral dicumaroids, preferably after resolution of thrombocytopenia. Further studies are required in order to elucidate the pathogenetic mechanism of thrombosis and its relation with inflammation; on the other hand large clinical trials are needed to confirm the best therapeutic strategies for HIT Type II.

Co-existence of two functional mutations on the same allele of the human ferrochelatase gene in erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is an autosomal dominant disease with incomplete penetrance due to reduced activity of ferrochelatase (FECH), a mitochondrial enzyme that catalyzes the final step of the heme biosynthetic pathway. The clinical phenotype of EPP results from co-inheritance of a mutated allele and a wild-type low-expressed allele of the FECH gene. To date, more than 88 different mutations have been identified in the FECH gene of patients with EPP. There are evidences suggesting that an entire haplotype (-251G, IVS1-23T and IVS3-48C) reduces allele expression. In this study, we searched for the -251A/G, IVS1-23C/T and IVS3-48T/C polymorphisms in two unrelated Italian families with EPP. In all the patients, carrying the -250G>C mutation in the promoter region, the IVS3-48C on the other allele showed apparent homozygosity and absence of Mendelian segregation. By RNA and long polymerase chain reaction analysis, we identified a deletion of 5576 bp (g12490_18067), including exons 3 and 4, in cis with the -250G>C mutation in the promoter.