Factors predictive of leg-ulcer healing in sickle cell disease: a multicentre, prospective cohort study.

BACKGROUND: Leg ulcers (LUs) are a chronic and severe complication of sickle cell disease (SCD). A prospective study in patients with SCD to identify factors associated with complete healing and recurrence of LUs is lacking. OBJECTIVES: To determine clinical and biological factors associated with SCD-LU complete healing and recurrence. METHODS: This prospective, observational cohort study was conducted at two adult SCD referral-centre sites (2009-2015) and included 98 consecutive patients with at least one LU lasting ≥ 2 weeks. The primary end points compared patients with healed vs. nonhealed LUs at week 24, and patients with vs. without recurrence during follow-up. RESULTS: The median (interquartile range) LU area, duration and follow-up were, respectively, 6·2 cm2 (3-12·8), 9 weeks (4-26) and 65·8 weeks (23·8-122·1). At week 24, LUs were healed in 47% of patients, while 49% of LUs recurred. Univariate analyses identified inclusion LU area < 8 cm2 (82% vs. 35%; P < 0·001), inclusion LU duration < 9 weeks (65% vs. 35%; P = 0·0013) and high median fetal haemoglobin level (P = 0·008) as being significantly associated with complete healing at week 24, and low lactate dehydrogenase level (P = 0·038) as being associated with recurrence. Multivariate analyses retained LU area < 8 cm2 (odds ratio 6·73, 95% confidence interval 2·35-19. 31; P < 0·001) and < 9 weeks' duration (OR 3·19, 95% confidence interval 1·16-8·76; P = 0·024) as being independently associated with healing at week 24. Factors independently associated with recurrence could not be identified. CONCLUSIONS: SCD-LU complete healing is independently associated with the clinical characteristics of LUs rather than the clinical or biological characteristics of SCD.

[The impact of screening sickle-cell carriers in the general population. A retrospective study in the Paris screening center]. / L'impact du dépistage du trait drépanocytaire en population. Une étude rétrospective au Centre d'information et de dépistage de la drépanocytose (Paris).

BACKGROUND: Since 2006 the CIDD, the Paris information and screening center for sickle-cell disease, provides free assistance for adults who may be at risk of having children with sickle-cell disease. Recently, an increasing number of parents of a silent-carrier newborn detected by systematic neonatal screening are attending the center. We present a retrospective study of the impact of such information and screening on people. METHODS: The study involved 81 silent-carrier men and women aged 18 to 45 years, interviewed using a telephone questionnaire (n=70) or during consultation (n=11) one to three years after screening. RESULTS: The study group represented 12% of individuals attending the center with the same characteristics. In general, the information delivered concerning sickle-cell disease and silent-carriers was well understood although concerns about personal and family history and the correctness of prior knowledge revealed a lack of information input from the environment (media, schools, health professionals). Poorly assimilated information involved three subjects: the difference between trait and disease; the difference between type of hemoglobin and blood group; and Mendelian transmission. The screening result was not a cause of separation among couples and was often passed on to family or friends. Disparities in adherence to prenatal diagnosis and termination of pregnancy were mainly related to different representations of disease severity. CONCLUSION: Joint screening of newborns and their parents is a good measure for adults, who are satisfied with being informed despite the psychological difficulties involved. However the implication for children detected remains a relevant issue because of the persistent perception of the trait as a pseudo-disease and the risk of reification of a biological difference between relatives.

Is procalcitonin a marker of invasive bacterial infection in acute sickle-cell vaso-occlusive crisis?

Fever is often present during painful vaso-occlusive crisis (VOC) in sickle-cell disease (SCD), but does not always indicate infection. The aim of our study was to test procalcitonin as a marker of invasive bacterial infection in VOC. Consecutive SCD adults hospitalized for VOC were included. Data were collected at admission and within 24 h after the onset of fever. We distinguished patients with clinically defined and microbiologically documented invasive bacterial infection from patients with no evidence of invasive bacterial infection and who fared well without antibiotics. One hundred and twelve patients were enrolled (61% females, median age 23 years, 88% homozygous SCD). All patients with procalcitonin (PCT) level ≥1 µg/L had an invasive bacterial infection, but two patients (33%) with an invasive bacterial infection had a PCT level <1 µg/L. High levels of PCT indicate invasive bacterial infection. However, a single low PCT level without follow-up measurement cannot rule out an invasive bacterial infection and should not withhold the prescription of antibiotics.

Comparison of two basophil activation markers CD63 and CD203c in the diagnosis of amoxicillin allergy.

BACKGROUND: To confirm allergy to beta-lactam (BL), a basophil activation test in flow cytometry based on CD63 up-regulation was described. CD203c is a more recent basophil activation marker and up to day there is no consensus about which marker is the more sensitive one. CD203c has not yet been evaluated in the diagnosis of BL allergy. OBJECTIVE: The aim of the study was to compare the reliability of CD203c to CD63 for the diagnosis of amoxicillin (AX) allergy, which is nowadays the most frequent BL allergy. METHODS: Twenty-seven patients with an immediate positive skin test (ST) to AX, 20 had had anaphylaxis with AX and 7 had urticaria and/or angioedema, were compared with 14 controls with no allergy to BL and to six patients with delayed positive ST to AX. RESULTS: In the anaphylaxis group, AX induced up-regulation of CD203c in the basophils of 12 patients out of 20 (60%) and of CD63 in four patients (20%) (P<0.02). Two patients out of seven with urticaria or angioedema had a positive result with CD203c and CD63. In patients who had anaphylaxis, ampicillin (AMP) induced CD203c up-regulation in eight out of 12 (67%) patients tested, and CD63 up-regulation in 4 out of 12 (33%) (all patients who had anaphylaxis could not be tested with AMP). False-positive results were observed with CD203c as well as CD63, and for 10 patients indeed this was confirmed by a negative drug provocation test. The origin of conflicting results between CD63 and CD203c might be at least the targeting of basophils based on anti-IgE labelling. Among IgE(+) gated cells, by means of CD33, a marker of monocytes, a contamination up to 50% by monocytes was detected. In contrast to CD63, CD203c is an activation marker specific of basophils with a basal low-level expression in resting basophils. Thus, IgE and CD203c double targeting of basophils avoids the contamination by monocytes. CONCLUSION: CD203c seems to be a more sensitive activation marker of basophils than CD63 for the diagnosis of amoxicillin allergy.

Unusual sites of Salmonella osteoarthritis in patients with sickle cell disease: two cases.

Salmonella osteoarticular infections involve mainly long bones such as the femur, tibia, and humerus in patients with sickle cell disease (SCD). We report here two unusual cases of Salmonella osteoarthritis affecting sacroiliac and sternoclavicular joints in two patients with SCD, one patient also being followed for rheumatoid arthritis. Because of misleading presentation, diagnosis of septic osteoarthritis in patients with SCD requires a high index of suspicion and an early treatment.

[Sickle cell disease in France in 2006: results and challenges]. / La drépanocytose en France en 2006: acquis et défis.

Sickle cell disease is currently recognized as the most frequent genetic disease screened in the neonatal period in France, and begins to be funded by Public Health Authorities. Despite these issues, SCD is still largely unknown, in particular by general public and practitioners, and education about the disease has to be intensified. Respective roles of proximate and reference centres have to be better defined. Screening of heterozygous patients remains to be organized. Limits of definition of a severe form, and therapeutic options need to be debated.

Plasma therapy against infectious pathogens, as of yesterday, today and tomorrow.

Plasma therapy consists in bringing to a patient in need - in general suffering a severe, resistant to current therapy, and even lethal infection - plasma or specific, fractioned, antibodies, along with other immunoglobulins and possibly healing factors that can be obtained from immunized blood donors; donors (voluntary and benevolent) can be either actively immunized individuals or convalescent persons. Plasma therapy has been used since the Spanish flu in 1917-1918, and regularly then when viral epidemics threatened vulnerable populations, the last reported occurrence being the 2013-2015 Ebola virus outbreak in West Africa. The precise action mechanism of plasma therapy is not fully delineated as it may function beyond purified, neutralizing antibodies.

[Current developments on sickle cell disease]. / Actualité de la drépanocytose.

Sickle cell disease is a genetic autosomal recessive disease of hemoglobin. The disease results from a mutation of the sixth codon of the beta-globin gene, which induces the synthesis of an abnormal hemoglobin called hemoglobin S (HbS). The polymerisation of deoxy HbS molecules causes a chronic hemolytic anemia and vaso-occlusive phenomenons. The disease affects mainly people from West Indies and Sub saharian Africa. Due to recent movements of these populations over the past years, sickle cell disease has spread across all continents. Painful crises, severe infections such as septicemia, meningitis, osteomyelytis, acute anemia episodes, and severe vaso-occlusive events, mainly neurological, are the most frequent complications affecting children. Recent progresses in the care of patients have deeply modified the prognosis. The mean life expectancy of patients is now above 40 years. The conventional treatment includes antibiotics and immunizations, analgesics, and blood transfusion. The effects of chronic blood transfusion, hydroxyurea and bone marrow transplantation are the subject of current comparative evaluations.

Maternal mortality among women with sickle-cell disease in France, 1996-2009.

OBJECTIVE: To describe maternal mortality among women with sickle-cell disease in France. STUDY DESIGN: Data from the national confidential enquiry into maternal deaths and from reference centres for sickle-cell disease were examined to identify women with this disease who died in France during 1996-2009. The maternal mortality ratio among women with sickle-cell disease was estimated and compared with the ratio in the general population. Characteristics of these women and their pregnancies and circumstances of their deaths were examined in detail. RESULTS: Fifteen maternal deaths occurred among an estimated 3300 live births to women with sickle-cell disease, for a maternal mortality ratio of 454 per 100000 live births (95% CI [254; 750]), versus 9.4/100000 in the general population. Ten women were homozygous (SS) for sickle-cell disease, and five were composite heterozygotes. The episode leading to death appeared in the antepartum period for seven women (47%). Two women died of septic shock during pregnancy, one at 6 weeks, the other at 24 weeks. The other 13 women (87%) died postpartum. Thirteen deaths were directly attributable to sickle-cell disease. The other two maternal deaths, both considered direct obstetric causes, were due to amniotic fluid embolism and septic shock after post-amniocentesis chorioamnionitis. The expert committee on maternal mortality judged seven of these 15 deaths (47%) to be avoidable. CONCLUSION: Sickle-cell disease is responsible for a major excess risk of maternal death in France, due mainly to direct complications of the disease.

DNA amplification of HIV-1 in seropositive individuals and in seronegative at-risk individuals.

We assessed the HIV-1 status of seropositive and seronegative at-risk individuals by the polymerase chain reaction. Fifty-four out of 55 HIV-1-seropositive samples scored positive. However, HIV-1 proviral DNA was not detected in 16 seronegative homosexuals, 20 seronegative polytransfused haemophiliacs and 20 seronegative thalassaemic children, 20 individuals with isolated and persistent anti-core antibodies and 74 seronegative blood donors. These data indicate that positive HIV-1 DNA is likely to be an exceptional phenomenon in HIV-seronegative people.

Normal growth hormone (GH) response to GH-releasing hormone in children with thalassemia major before puberty: a possible age-related effect.

The plasma GH response to a single iv bolus dose of 2 micrograms/kg BW synthetic GHRH-(1-44)NH2 was evaluated in 13 prepubertal children with thalassemia major (mean age, 7.6 +/- 0.8 yr) with growth retardation and in 15 prepubertal children with nonendocrine short stature. All of the patients showed a significant increase in plasma GH concentration, with a mean peak of 31.4 +/- 4.5 micrograms/L at 15 min (P less than 0.001 vs. basal values; range, 18.4-65 micrograms/L) after GHRH, which was not different from that of the control group of idiopathic short stature children (40.1 +/- 3.4 micrograms/L; range, 21-65.4 micrograms/L). All but 1 of the thalassemic patients had a normal GH response to the arginine-insulin stimulation test. The mean plasma insulin-like growth factor-I level was low (0.12 +/- 0.05 U x 10(3)/L; range, less than 0.02-0.61 U x 10(3)/L). Analysis of these results as well as previously reported data indicating that older thalassemic patients have an impaired GH response indicates that there may be an age-related pituitary and/or hypothalamic dysfunction in thalassemic children. This study also confirms that the insulin-like growth factor-I decrease occurs before any alteration in GH secretion. These changes might play a role in the early growth retardation that occurs in these patients.

No evidence for a defect in growth hormone binding to liver membranes in thalassemia major.

To test the hypothesis of a defect in GH-receptor interaction, which could explain the growth failure of thalassemic children, the binding of [125I]human (h) GH to membrane fractions prepared from liver biopsies was studied. Small amounts of liver were obtained from 6 girls and 11 boys with homozygous beta-thalassemia, aged 3-15 yr, all prepubertal, at the time of splenectomy. Specific binding of [125I]hGH ranged from 0.37-5.11% of the added radioactivity/100 micrograms liver membrane protein, with variations in both receptor number and binding affinity. This 14-fold variation in hGH binding to liver membranes of thalassemic children was comparable to that in membrane fractions of livers obtained from normal donors at the time of liver transplant. The binding of insulin to liver membranes from the thalassemic patients ranged from 9.8-17.9% of the added radioactivity/100 micrograms membrane protein and from 2.8-15.0%/100 micrograms membrane protein in the normal donors. Insulin and GH binding to liver membranes did not vary in a consistent way. A 3-fold difference was found in 5'-nucleotidase activity of the membrane fractions. Histological hepatic modifications were assessed with respect to siderosis and fibrosis. No correlation was found between these parameters and GH binding. These results suggest that possible membrane alterations are not the only reason for the variations in hGH binding. All patients had retarded growth, and all but 2 had low plasma insulin-like growth factor I levels. No relationship was found between the level of GH binding to liver membranes and the growth failure. Thus, a defect in GH binding to liver membranes is probably not the cause of the growth retardation of thalassemic children.

Calcium phosphate metabolism and bone disease in patients with homozygous thalassemia.

Calcium and phosphate metabolism were studied in 22 patients with homozygous thalassemia. The overall results showed no significant difference for serum calcium, phosphorus, alkaline phosphatase, immunoreactive parathyroid hormone, or 25-hydroxyvitamin D between thalassemic and control children. However, during the winter, serum 25-hydroxycholecalciferol levels were very significantly decreased in thalassemic children. A study of the hands showed thin metacarpal cortices related to increased resorption. Histomorphometric study of four iliac bone biopsies showed normal osteoclastic resorption and decreased bone formation. Prussian blue staining and x-ray electron microprobe analysis showed iron deposits inside the bone. Whether this finding is critical in the pathogenesis of the bone disease in unknown.

Genetic polymorphism of the mannose-binding protein gene in children with sickle cell disease: identification of three new variant alleles and relationship to infections.

Mannose-binding protein (MBP) is a serum lectin that participates in the innate immune response. MBP deficiency may constitute a risk factor in the development of infections. Three MBP structural variants have been identified with a dominant effect on MBP serum concentration. Similarly, polymorphisms in the promoter of the corresponding gene (HSMBP1B) have been related to variations of MBP concentration in serum. Children with sickle cell disease (SCD) have an increased susceptibility to infections with encapsulated organisms resulting in meningitis, septicaemia, and osteomyelitis. We have investigated the HSMBP1B genotype in 242 children with SCD living in Paris. Apart from the known variant alleles, we identified three novel ones and report their distribution in our sample population. In addition, we found rather unexpectedly an increased frequency of the variant alleles in patients who had not suffered severe infections.

Mössbauer spectroscopy study of iron overloaded livers.

Absorption 57Fe Mössbauer spectra have been carried out directly on fresh or lyophylized tissues of liver with either normal iron depot or iron overload. Two types of overloading have been studied: primary iron overload due to an excessive intestinal iron absorption and secondary iron overload (hemosiderosis) produced in beta-thalassemia patients by hypertransfusional therapeutics. The Mössbauer spectra, at room temperature, 77 and 4.2 K, on normal liver samples, are typical for the ferritin-hemosiderin compounds. In the spectra, performed on hemosiderosis liver samples, there appears, in addition to ferritin and hemosiderin, a new iron molecular environment, typical of high spin ferric iron and characterized by a superparamagnetic behaviour which begins at high temperature (above 77 K). This new component does not show up in the primary iron overload cases and seems characteristic of the physiological process which induces the iron overload.

Increased procoagulant activity of red blood cells from patients with homozygous sickle cell disease and beta-thalassemia.

It has recently been proved that, in vitro, red blood cells (RBCs) from patients with homozygous beta-thalassemia behave as procoagulant cells. The procoagulant activity of beta-thalassemia RBCs might be the result of an increased exposure of procoagulant phospholipids (i.e. phosphatidylserine) in the outer leaflet of the membrane. In order to test this hypothesis, we compared the catalytic properties of RBCs of patients with beta-thalassemia and homozygous sickle cell disease (SS-RBCs) with that of controls. The catalytic parameters (Km, kcat) of prothrombin activation by factor Xa were determined both in the absence and in the presence of RBCs. The turn-over number (kcat) of the reaction was not modified by normal, SS- or beta-thalassemia RBCs. The Km was lower in the presence of normal RBCs (mean value: 9.1 microM) than in the absence of cells (26 microM). The Km measured in the presence of either SS-RBCs (mean value: 1.6 microM) or beta-thalassemia RBCs (mean value: 1.5 microM) was significantly lower compared to normal RBCs (p < 0.001). No significant difference was observed between SS-RBCs and beta-thalassemia RBCs. Annexin V, a protein with high affinity and specificity for anionic phospholipids, inhibited the procoagulant activity of both SS-RBCs and beta-thalassemia RBCs, in a dose-dependent manner. More than 95% inhibition was achieved at nanomolar concentrations of annexin V. These results indicate that the procoagulant activity of both beta-thalassemia RBCs and SS-RBCs may be fully ascribed to an abnormal exposure of phosphatidylserine at the outer surface of the red cells.

Albumin, fibrinogen, prothrombin and antithrombin III variations in blood, urines and liver in rat nephrotic syndrome (Heymann nephritis).

Albumin, fibrinogen, prothrombin and antithrombin III (AT III) variations have been studied in blood, urines and liver during an experimental nephrotic syndrome in rats (Heymann nephritis). A quantitative morphometric study (light microscopy) has been performed in the liver using an immunocytochemical technique--(PAP) method--to evaluate the protein synthesis by the number of protein-containing hepatocytes. Some sections were also studied by electron microscopy. The nephrotic animals were compared with control rats. In the blood of nephrotic rats, fibrinogen and prothrombin concentrations were increased and albumin and AT III concentrations were decreased. In the urines of nephrotic rats, albumin, prothrombin and AT III were lost, but no fibrinogen. The morphometric study in the liver has shown a significantly higher number of fibrinogen and prothrombin-containing hepatocytes in nephrotic rats than in controls, suggesting an increased synthesis of these proteins; no change was observed concerning albumin and AT III between nephrotic and control animals. In electron microscopy, albumin was demonstrated in Golgi apparatus, proving that the peroxidase-positive cells are related to protein synthesis. These results show that the mechanisms of regulation of the protein synthesis during nephrotic syndrome are different from one protein to another and, particularly, that their blood level is not the only regulating factor for their synthesis.

Donor for BMT with haemoglobin H disease.

We report a successful allogeneic BMT for the treatment of juvenile chronic myelogenous leukemia (JCML) in a 9-month-old Laotian boy using an HLA-matched sibling donor with HbH disease (--SEA/aaCS). In addition, before BMT the recipient had a complex haemoglobinopathy associating heterozygous state AE along with HbH disease (--SEA/-a3,7) without haemoglobin Constant Spring (HbCS). Because various haemoglobinopathies are frequently encountered in southeast Asia, when BMT is performed in Asian families the results may be evaluated by the differing haemoglobin characteristics of recipient and donor. However, there is also a significant risk of transmitting a new haemoglobinopathy to the recipient. Because transplantation from HLA-identical siblings offers the only chance of cure for JCML, the presence of HbH disease with mild clinical expression in the donor should not be taken as a contra-indication to BMT.