The mutational spectrum of hunter syndrome reveals correlation between biochemical and clinical profiles in Tunisian patients.

BACKGROUND: Mucopolysaccharidosis type II (MPS II) or Hunter syndrome is an X-linked recessive lysosomal storage disorder resulting from deficient activity of iduronate 2-sulfatase (IDS) and the progressive lysosomal accumulation of sulfated glycosaminoglycans (GAGs). METHODS: A diagnosis of MPS II or Hunter syndrome was performed based on the following approach after a clinical and paraclinical suspicion. Two biochemical and molecular tests were carried out separately and according to the availability of the biological material. RESULTS: All patients in this cohort presented the most common MPS II clinical features. Electrophoresis of GAGs on a cellulose acetate plate in the presence of a high concentration of heparane sulfate showed an abnormal dermatan sulfate band in the patients compared with that in a control case. Furthermore, leukocyte IDS activity ranged from 0.00 to 0.75 nmol/h/mg of leukocyte protein in patients. Five previously reported mutations were identified in this study patients: one splice site mutation, c.240 + 1G > A; two missense mutations, p.R88P and p.G94D; a large deletion of exon 1 to exon 7; and one nonsense mutation, p.Q396*. In addition, two novel alterations were identified in the MPS II patients: one frame shift mutation, p.D450Nfs*95 and one nonsense mutation, p.Q204*. Additionally, five known IDS polymorphisms were identified in the patients: c.419-16 delT, c.641C > T (p.T214M), c.438 C > T (p.T146T), c.709-87G > A, and c.1006 + 38 T > C. CONCLUSIONS: The high level of urine GAGs and the deficiency of iduronate 2-sulfatase activity was associated with the phenotype expression of Hunter syndrome. Molecular testing was useful for the patients' phenotypic classification and the detection of carriers.

How to mitigate the risk of inducing transfusion-associated adverse reactions.

Transfusion has become extremely safe but can still be associated with adverse reactions. Some adverse reactions can be mitigated by applying measures to donor selection, the process of separating blood components as well as hospital-based procedures consisting in matching the donor and the recipient; special attention is given to optimizing the best fit between the component and the beneficiary, which is not only an immuno-hematological challenge (fresh versus old blood, testing for certain viruses such as CMV, parvovirus B19, etc.). Considerable progress has also been achieved to strengthen the overall quality and safety of the whole transfusion chain. Guidelines and recommendations have resulted in substantial progress, and the recent revisiting of patients as part of a more holistic approach has enabled blood management programs to be created. Such programs, when wisely applied in a context of optimal blood use, reinforce patient safety; they enhance hospital recognition of transfusion and hemovigilance specialists as useful players acting in the interests of patients in full compliance with hospital budgets. This review considers the step-by-step processes that reinforce transfusion safety and identifies hurdles that cannot yet be properly addressed; it proposes steps for further progress, in light of personalized medicine.

Transfusion-associated hazards: A revisit of their presentation.

As a therapy or a support to other therapies, despite being largely beneficial to patients in general, transfusion it is not devoid of some risks. In a moderate number of cases, patients may manifest adverse reactions, otherwise referred to as transfusion-associated hazards (TAHs). The latest French 2016 haemovigilance report indicates that 93% of TAHs are minor (grade 1), 5.5% are moderate (grade 2) and 1.6% are severe (grade 3), with only five deaths (grade 4) being attributed to transfusion with relative certainty (imputability of level [or grade] 1 to 3). Health-care providers need to be well aware of the benefits and potential risks (to best evaluate and discuss the benefit-risk ratio), how to prevent TAHs, the overall costs and the availability of alternative therapeutic options. In high-income countries, most blood establishments (BEs) and hospital blood banks (HBBs) have developed tools for reporting and analysing at least severe transfusion reactions. With nearly two decades of haemovigilance, transfusion reaction databases should be quite informative, though there are four main caveats that prevent it from being fully efficient: (ai) reporting is mainly declarative and is thus barely exhaustive even in countries where it is mandatory by law; (aii) it is often difficult to differentiate between the different complications related to transfusion, diseases, comorbidities and other types of therapies in patients suffering from debilitating conditions; (aiii) there is a lack of consistency in the definitions used to describe and report some transfusion reactions, their severity and their likelihood of being related to transfusion; and (aiv) it is difficult to assess the imputability of a particular BC given to a patient who has previously received many BCs over a relatively short period of time. When compiling all available information published so far, it appears that TAHs can be analysed using different approaches: (bi) their pathophysiological nature; (bii) their severity; (biii) the onset scheme; (biv) a quality assessment (preventable or non-preventable); (bv) their impact on ongoing therapy. Moreover, TAHs can be reported either in a non-integrative or in an integrative way; in the latter case, presentation may also differ when issued by a blood establishment or a treating ward. At some point, a recapitulative document would be useful to gain a better understanding of TAHs in order to decrease their occurrence and severity and allow decision makers to determine action plans: this is what this review attempts to make. This review attempts to merge the different aspects, with a focus on the hospital side, i.e., how the most frequent TAHs can be avoided or mitigated.

Platelet and TRALI: From blood component to organism.

Even though used systematically with leukocyte reduction, platelet transfusions still cause adverse reactions in recipients. They include Transfusion-Related Acute Lung Injury (TRALI), respiratory distress that occurs within six hours of the transfusion. The pathophysiology of this transfusion complication brings complex cellular communication into play. The role, particularly inflammatory, played by blood platelets in TRALI pathophysiology has been demonstrated, but is still under debate. Blood platelets play a role in inflammation, particularly via the CD40/CD40L (sCD40L) immunomodulator complex. In this study, we examine in particular the specific involvement of the CD40/CD40L (sCD40L) complex in the inflammatory pathogenesis of TRALI. This molecular complex could be a major target in a TRALI prevention strategy. Improving the conditions in which the platelet concentrates (PC) are prepared and stored would contribute to controlling partly the risks of non-immune TRALI.

Platelets and immunity: From physiology to pathology.

Blood platelets are cells acting during primary haemostasis. The thrombocytopenia observed in many different types of infectious processes begs the question of the relationship between cells and infectious pathogens and the role of platelets in the detection of biological hazards. This in turn brings us back to the role of platelets - via their molecular, membrane and secretory arsenal - in the detection and repair of vascular hazards. The common denominator between a breakdown of haemostasis and the risk of infection has been shown to be a cutoff point in the inflammatory continuum between physiology and physiopathology. The trophic role of platelets - as topical factor and as platelet transfusions - and their inflammatory complexities appear to correlate this proposed model, as reported in this short review.

[Neonatal expression of beta-thalassemia trait associated with hereditary spherocytosis in two monozygotic twins]. / Expression néonatale d'un trait bêta-thalassémique associé à une sphérocytose héréditaire chez deux jumelles monozygotes.

The beta-thalassemia trait is a heterozygous beta-thalassemia characterized by a partial deficiency of the synthesis of beta-globin chains of hemoglobin. It is usually asymptomatic and the diagnosis is often made on the occasion of the completion of a systematic blood count or a family survey. Clinical expression during the neonatal period is impossible and its association with hereditary spherocytosis is common. We report two monozygotic twins who, on the 3rd day of life, presented intense jaundice, unconjugated bilirubin associated with anemia, without hepatosplenomegaly. Laboratory tests found nonimmune hemolytic anemia with microcytosis and hypochromia justifying iterative blood transfusions. The etiological investigation found heterozygous beta-thalassemia associated with hereditary spherocytosis. The family investigation and molecular analysis objectified the beta-thalassemic mutation IVS1nt110 (G→A) in the heterozygous state in the twins, the father, the mother, and in one of the two brothers. With any nonimmune hemolytic anemia in newborns, the etiological investigation should be systematic for early diagnosis and to plan appropriate treatment.

Transfusion as an Inflammation Hit: Knowns and Unknowns.

Transfusion of blood cell components is frequent in the therapeutic arsenal; it is globally safe or even very safe. At present, residual clinical manifestations are principally inflammatory in nature. If some rare clinical hazards manifest as acute inflammation symptoms of various origin, most of them linked with conflicting and undesirable biological material accompanying the therapeutic component (infectious pathogen, pathogenic antibody, unwanted antigen, or allergen), the general feature is subtler and less visible, and essentially consists of alloimmunization or febrile non-hemolytic transfusion reaction. The present essay aims to present updates in hematology and immunology that help understand how, when, and why subclinical inflammation underlies alloimmunization and circumstances characteristic of red blood cells and - even more frequently - platelets that contribute inflammatory mediators. Modern transfusion medicine makes sustained efforts to limit such inflammatory hazards; efforts can be successful only if one has a clear view of each element's role.

[Blood transfusion and inflammation as of yesterday, today and tomorrow]. / Transfusion et inflammation : hier - aujourd'hui - demain.

Blood transfusion is made possible principally by use of donated homologous components that - in turn - can be perceived as sources of danger by recipients. This may create an innate immune response dominated by inflammation, especially when transfusion is repeated. Residual leukocytes in blood components can source inflammatory lesions but considerably less than used to be prior to systematic, early and stringent - in process - leukoreduction. Every blood component can cause inflammation, though barely in the case of therapeutic plasma (in such a case, this is mainly restricted to allergy). Iron that may be freed by red blood cells but also processing and storage lesions such as the emission of microparticles can reveal themselves as pro-inflammatory. Platelets in platelet components represent the main source of inflammatory and/or allergic hazards in transfusion; this is linked with processing and storage lesions but also with the platelet physiology itself. It is of utmost importance to avoid inflammatory adverse events in patients that are fragile because of their primary condition and/or treatment; this stands for their safety, as inflammation can be extremely severe and even lethal, and also for their comfort; this increases efficacy of transfusion programs while reducing the overall costs.

Amotosalen-HCl-UVA pathogen reduction does not alter poststorage metabolism of soluble CD40 ligand, Ox40 ligand and interkeukin-27, the cytokines that generally associate with serious adverse events.

Platelets in therapeutic platelet concentrates are commonly acknowledged to release biologically active constituents during storage. This study examined the influence of photochemical pathogen reduction treatment (PRT) using amotosalen-HCl and UVA light vs. untreated control platelet components, on three factors recently reported to be associated with serious adverse events associated with platelet component (PC) transfusions: sCD40L, IL-27 and sOX40 ligand. Levels of such cytokine-like factors increased significantly during storage, but no significant difference was detected between PRT- and control PCs. This suggests that occurrences of AEs are not directly influenced by PRT but rather may depend on alternate determinants.

Mutations and polymorphisms in N-acetylgalactosamine-6-sulfate sulfatase gene in Turkish Morquio A patients.

Mucopolysaccharidosis type IVA (MPS IVA) is an autosomal recessive inherited metabolic disease resulting from deficiency of N-acetylgalactosamine-6-sulfatase (GALNS). This lysosomal storage disorder leads to a wide range of clinical variability ranging from severe, through intermediate to mild forms. The classical phenotype of Morquio A disease is characterized by severe bone dysplasia without intellectual impairment. Two severe MPS IVA patients from two unrelated Turkish families have been investigated. The 14 exons and intron-exon junctions of the GALNS gene were sequenced after amplification from genomic DNA. Direct sequencing revealed two homozygous mutations previously described: p.L390X in exon 11 and p.W141R in exon 4. The p L390X mutation was associated with four novel polymorphisms in intron 2, intron 5 and intron 6 and one polymorphism previously described in exon 7. We have analysed the haplotypes associated with the two identified mutations. These molecular findings will permit accurate carrier detection, prenatal diagnosis and counseling for Morquio A syndrome in Turkey.

[Blood transfusion and inflammation]. / Transfusion sanguine et inflammation.

Transfusion of labile blood products (LBPs) generates occasional inflammatory : type, hazards; for a large part of these, no antigen/antibody conflict is thus, detected. Residual leucocytes used to account for a large part of such incidents - rarely accidents. Since, however, the systematic leukoreduction of LBPs, leucocytes are the less and less incriminated in adverse events. Platelets themselves proved capable of secreting copious amounts of inflammatory mediators, even in the absence of any deliberated stimulation. Meanwhile, even though exceptionally, inflammation can be observed after red blood cell transfusion. It has been noticed that the collection mode of cellular compounds, as well as the preparation and storage conditions are capable of inflicting lesions to the cell membranes and to activate those cells, and thus promoting inflammatory responses. Storage lesions as well as ageing of the stored cells alongside with cell apoptosis contribute to inflammatory responses. This present 'State of the Art' paper aims at encompassing the primary and secondary components of the LBPs, along with the various types of molecules displaying pro-inflammatory properties that can be encountered in transfusion. A better knowledge of causes of inflammatory transfusion-linked hazards is indeed instrumental to the implementation of safety measures aimed at reducing or suppressing these unwanted effects.

Mucopolysaccharidosis IVA within Tunisian patients: Confirmation of the two novel GALNS gene mutations.

UNLABELLED: Mucopolysaccharidosis type IVA or Morquio A disease is an autosomal recessive disease resulting from a deficiency of the lysosomal enzyme N-acetylgalactosamine-6-sulfate-sulfatase, which hydrolyses N-acetylgalactosamine-6-sulfate and galactose-6-sulfate in glycosaminoglycans. Phenotypes in Morquio A disease vary from the classical form with severe bone dysplasia, heart valve involvement, corneal opacity, short trunk dwarfism and a life span of 20 to 30 years, to attenuated forms with normal life span, mild bone involvement and mild visceral organ involvement. Unlike the other forms of mucopolysaccharidoses, Morquio A disease is characterized by normal intelligence. AIM OF THE STUDY: The aims of this study were to determine if the novel GALNS anomalies IVS1+1G-A and G66R identified in Tunisia are mutations or polymorphisms. PATIENTS AND METHODS: This study was carried out on six Morquio A patients recruited from many regions of Tunisia. We have used SCCP, sequencing and enzymatic digestion. RESULTS: IVS1+1G-A and G66R were two deleterious mutations and not polymorphisms. CONCLUSION: Screening of mutations and polymorphisms in GALNS gene provide useful information on genotype/phenotype correlations. It should also facilitate more accurate genetic counselling of newly diagnosed cases and their family members.

Mucopolysaccharidoses type I and IVA: clinical features and consanguinity in Tunisia.

UNLABELLED: Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders caused by the deficiency of specific enzymes which leads to the lysosomal accumulation of glycosaminoglycanes. Mucopolysaccharidosis type I or Hurler disease is characterized by the deficiency of alpha-l-iduronidase enzyme. Mucopolysaccharidosis type IVA or Morquio A disease is due to the lack of N-acetylgalactosamine-6-sulfate-sulfatase. Theses deficiencies result in a progressive accumulation of the substrates: dermatan and heparan sulfates for Mucopolysaccharidosis type I and keratan sulfate for MPS type IVA. This process leads to progressive and chronic course for visceral attacks of the affected organs such as lungs and heart. In the Hurler disease, the nervous system is particularly affected while in Morquio a disease, a skeletal dysplasia and a normal intelligence are characteristic. AIM OF THE STUDY: This study was carried out on MPS type I and MPS type IVA unrelated families recruited from many regions of Tunisia in order to determine the relation between consanguinity and these types of disorders. PATIENTS AND METHODS: Clinical and molecular analyses confirmed the diagnosis for four MPS type I and five MPS type IVA studied families. RESULTS: First cousins unions characterize all families except one Hurler family and one Morquio A family where the consanguinity is third cousin degree. CONCLUSION: MPS type I and type IVA seems to be associated with consanguinity in Tunisia.

[Molecular analysis of the p.Asn 370 Ser mutation in Gaucher disease]. / Analyse moléculaire de la mutation p.Asn 370 Ser dans la maladie de Gaucher.

Gaucher disease is one of the most prevalent lysosomal disorders. In this present study, we report a diagnostic strategy of type 1 Gaucher disease. The application of combined methods in molecular biology allowed us to analyse the p.Asn 370 Ser mutation. The affected individual activity is very low. First, we have to used the enzymatic digestion method. Then, we have to identified the mutation by the refractory mutation system technique using specific primers for the p.Asn 370 Ser mutation. These analyses are supplemented by the direct sequencing in order to seek and confirm this mutation. Finally, the absence of the 55 pb deletion in exon 9 among corroborated the presence of the homozygous genotype of this p.Asn 370 Ser in the patient DNA.

[Biochemical and molecular diagnosis of Gaucher disease in Tunisia]. / Diagnostic biochimique et moléculaire de la maladie de Gaucher en Tunisie.

Our study was carried out at a family from the Sahel (Tunisia). The father (index case) and his two children (son and daughter). The father beta-glucocerebrosidase (GCB) activity showing a deficit. These biochemical analyses are supplemented by molecular studies: enzymatic digestion and the direct sequencing. Two mutations were analysed, the p.Asn 370 Ser and the p.Leu 444 Pro. The DNA sequencing confirmed the presence of the homozygous genotype of this p.Asn 370 Ser in the father DNA and the heterozygous one in the two children DNA. It has no detection of the 55 pb deletion in exon 9 among all the specimens of DNA treated. The mutation p.Asn 370 Ser is associated with Gaucher disease type 1 correlated of a total absence of neurological involvements.

[Mucopolysaccharidosis type I: identification of alpha-L-iduronidase mutations in Tunisian families]. / La mucopolysaccharidose de type I: identification des mutations du gène alpha-L-iduronidase dans des familles tunisiennes.

UNLABELLED: Mucopolysaccharidosis type I (MPS I) is a lysosomal disease due to mutations in the gene encoding alpha-l-iduronidase (IDUA) leading to variable clinical phenotypes with progressive severe organomegaly, bone and neurological involvement in the most severe forms. The aim of our study was to propose in Tunisia a strategy of molecular and prenatal diagnosis of the MPS I. POPULATION AND METHODS: Our study was carried out on 8 MPS I patients recruited from different Tunisian regions and issued from 5 unrelated families. All the patients were offspring of consanguineous marriages. RESULTS: The clinical and biological study led to diagnose 5 Hurler patients and 3 Hurler-Scheie patients. Three IDUA mutations were identified by molecular analysis within 6 different families: a novel mutation p.F602X and 2 already described mutations p.P533R and p.R628X. DISCUSSION: MPS I is a heterogeneous disease characterized by variability of the phenotypes. The missense mutation p.P533R associated with the intermediate phenotype was the most frequent in the Tunisian but also in the Moroccan population. In Tunisia, the incidence of p.P533R mutation seems to be associated with the high frequency of consanguineous marriages. CONCLUSION: The identification of known MPS I mutations (p.P533R and p.R628X) and of the novel mutation p.F602X permits reliable genetic counselling of at-risk relatives and molecular prenatal diagnosis.

[Diagnostic strategy of mucopolysaccharidosis type I in Tunisia]. / La mucopolysaccharidose de type I: stratégie diagnostique en Tunisie.

A Tunisian patient affected by mucopolysaccharidosis (MPS) was investigated for a biological analysis (quantitative and qualitative glycosaminoglycans (GAG) screening). We have also done an enzymatic determination of alpha-L-iduronidase activity (IDUA). The most common mutation (p.Gln 70 X, p.Trp 402X and p.Pro 533 Arg) were researched by an enzymatic restriction and sequencing of the IDUA gene. Enzymatic and urinary diagnostics suggested a MPS I phenotype. The patient investigated had the mutation p.Pro 533 Arg in the homozygous status, whereas his parents were heterozygous for this mutation.

[Mucopolysaccharidosis IVA (Morquio A syndrome): clinical, biological and therapeutic aspects]. / La mucopolysaccharidose IVA (syndrome de Morquio A): aspects clinique, biologique et thérapeutique.

Mucopolysaccharidosis IVA (MPS IVA; Morquio A disease) is an autosomal recessive lysosomal storage disorder caused by a genetic deficiency of the N-acetylgalactosamine-6-sulfate sulfatase (GALNS; E.C.3.1.6.4). GALNS is required to degrade keratan sulfate (KS) and chondroitine-6-sulfate (C6S). The accumulation of undegraded substrates in lysosomes of the affected tissues leads to a systemic bone dysplasia. Total urine glycosaminoglycans (GAG) in patients with MPS IVA are close to the normal range so it is difficult to distinguish this disease based on urine GAG excretion. Another potential disease marker could be KS levels in urine and plasma. Although the enzymatic diagnosis of affected patients with MPS IVA can be made, the detection of obligate heterozygotes by enzymatic measurement is less reliable because of a marked overlap of GALNS in fibroblasts or leucocytes from affected phenotype and normal controls. The genetic heterozygoty of MPS IVA has been facilitated by the isolation and characterization of the full lengh cDNA encoding human GALNS. Conventional therapy is symptomatic and limited to palliative procedures, which have virtually no impact upon mortality. To date, there is still no general consensus about the effectiveness of bone marrow transplantation. In the future, gene therapy could represent a great therapeutic improvement.

[Clinical, biologic and molecular characteristics of two Tunisian MPS IV A patients]. / Etude de la maladie de Morquio A dans une famille tunisienne présentant deux enfants atteints.

Mucopolysaccharidosis type IV A (MPS IV A) is an autosomal recessive disorder resulting from the deficient activity of the lysosomal enzyme, N-acetylgalactosamine-6-sulfate sulfatase (GALNS) and the progressive lysosomal accumulation of keratane sulfate. Clinically, the MPS IV A differs from the other MPS by the localisation of the keratane sulfate in skelet and in eyes associated to the conservation of a normal intelligence. To date, the characterization and purification of the GALNS gene made a research for pathogenic mutations in patients with MPS IV A easier. These mutations are responsible of severe, intermediate or mild phenotype. The aim for this work was the research of clinical, biologic and molecular characteristics of two Tunisian MPS IV A patients who were offsprings of consanguineous mating. Enzymatic and urinary diagnostics suggested a MPS IV A phenotype. A novel homozygous mutation IVS1+1G-A was identified by direct sequencing in the GALNS gene of the two patients. Identification of GALNS mutations provide genotype/phenotype correlations and permit the precision of anomalies responsible of Morquio A phenotype in concerned families.