Risk factors for heart disease in transfusion-dependent thalassemia: serum ferritin revisited

Heart disease remains a leading cause of morbidity and mortality in transfusion-dependent thalassemia (TDT), which can be attributed to several factors but primarily develops in the setting of iron overload. This was a retrospective cohort study utilizing Webthal^® patient data from five major centers across Italy. Patients without heart disease were followed-up for 10 years (2000-2010) and data were collected for demographics, splenectomy status, serum ferritin and hemoglobin levels, and comorbidities associated with heart disease. Among 379 patients analyzed (mean age 22.9 ± 5.1 years, 47.8% men), 44 (cumulative incidence: 11.6%) developed heart disease during the period of observation. Splenectomy (p = 0.002) and serum ferritin level (p < 0.001) were the only risk factors with significant association with heart disease. A serum ferritin threshold of ≥ 3000 ng/mL was the best predictor for the development of heart disease (86.4% sensitivity and 92.8% specificity, AUC: 0.912, 95% CI 0.852-0.971, p < 0.001). On multivariate analysis, only a serum ferritin level ≥ 3000 ng/mL remained significantly and independently associated with increased risk of heart disease (HR: 44.85, 95% CI 18.85-106.74), with a 5- and 10-year heart disease-free survival of 58 and 39%. The association between iron overload and heart disease in patients with TDT is confirmed, yet a new serum ferritin level of 3000 ng/mL to flag increased risk is suggested.

Impact of heart magnetic resonance imaging on chelation choices, compliance with treatment and risk of heart disease in patients with thalassaemia major

This study aimed to verify the impact of heart magnetic resonance imaging on chelation choices and patient compliance in a single-institution cohort as well as its predictive value for heart failure and arrhythmias. Abnormal cardiac T2* values determined changes in treatment in most subjects. Heart T2* was confirmed to be highly predictive over 1 year for heart failure and arrhythmias. The choice of chelation regimens known to remove heart iron efficiently was not sufficient by itself to influence the risk. Compliance with treatment had a more remarkable role.

Encoding a superantigen by Staphylococcus aureus does not affect clinical characteristics of infected atopic dermatitis lesions

BACKGROUND

Bacterial infection with Staphylococcus aureus is a known trigger for the worsening of atopic dermatitis (AD). Staphylococcal superantigens have been theorized to make a potential contribution to this worsening of AD seen with infection.

OBJECTIVES

We sought to assess whether encoding a superantigen by S. aureus affects the inflammatory characteristics of impetiginized AD skin lesions.

METHODS

Fifty-two children with clinically impetiginized lesions of AD which were positive for S. aureus were enrolled in this study. A lesion was graded clinically using the Eczema Area and Severity Index (EASI), and then wash fluid was obtained from the lesion for quantitative bacterial culture, and measurement of bacterial products lipoteichoic acid and staphylococcal protein A and cytokines. The staphylococcal isolate was tested for antibiotic susceptibilities and the presence of a superantigen.

RESULTS

Fifty-four per cent (28 of 52) of the staphylococcal isolates encoded a superantigen. The presence of a superantigen had no significant effect on EASI score, amounts of bacterial products or inflammatory cytokines in the AD lesion.

CONCLUSIONS

These studies suggest that the expression of a superantigen by S. aureus alone does not play an important role in the increased skin inflammation associated with staphylococcal infection in childhood AD.

Clinical and molecular analysis of haemoglobin H disease in Sardinia: haematological, obstetric and cardiac aspects in patients with different genotypes

In this study, 251 Sardinian patients (187 adults and 64 children) with haemoglobin (Hb) H disease were evaluated. Two-hundred and sixteen patients (86%) had the deletional type (- -/-alpha) and 36 (14%) patients had the non-deletional type (- -/alpha(ND)alpha). A clear genotype-phenotype correlation was found, with the non-deletional type more severe than the deletional type. Diagnosis of Hb H disease was incidental in about 60% of cases. Aplastic crises due to B19 parvovirus infection were found in five patients (2.1%), while 23 patients (9.6%) experienced one or more haemolytic crises. Nineteen patients with Hb H received sporadic red blood cell transfusions and three patients were repeatedly transfused. Forty-seven of 61 married women (77%) had 82 pregnancies. In children, mean serum ferritin was 87 +/-92 mug/l and in adults, was 192 +/- 180 mug/l in females and 363 +/- 303 mug/l in males. For the 98 male patients, a significant correlation was found between ferritin values and age (r2 = 0.33, P < 0.0001). In the Sardinian population, Hb H disease needs regular monitoring for early detection and treatment of possible complications, such as worsening of anaemia that may require red cell transfusion, cholelithiasis and iron overload.

Combined therapy with deferiprone and desferrioxamine in thalassemia major

BACKGROUND AND OBJECTIVES

Effective and convenient iron chelation remains one of the main targets of clinical management of thalassemia major. The combined treatment with desferrioxamine and deferiprone could have an increased chelation efficacy and sometimes allow drug doses and toxicity to be reduced and the number of days of desferrioxamine infusion to be decreased, improving compliance and quality of life.

DESIGN AND METHODS

We used combined therapy with desferrioxamine and deferiprone to treat 79 patients with severe iron overload (serum ferritin higher than 3000 ng/mL) who had low compliance with subcutaneous desferrioxamine.

RESULTS

Total therapy exposure was 201 patient-years. Three patients developed agranulocytosis and seven mild neutropenia. Other adverse effects were nausea, vomiting, abdominal pain, increased concentrations of liver transaminases and joint pain. The efficacy of combined therapy was evaluated in 64 patients treated for at least 12 months. Ferritin decreased from 5243+/-2345 to 3439+/-2446 ng/mL, p<0.001). Mean urinary iron excretion during combined therapy was double that with desferrioxamine or deferiprone monotherapy. In 20 patients receiving heart therapy at baseline, left ventricular ejection fraction increased from 48.6+/-9% to 57+/-6% (p=0.0001) over 12 to 57 months, without modifying the cardiac treatment.

INTERPRETATION AND CONCLUSIONS

Continuous deferiprone treatment with intermittent administration of subcutaneous desferrioxamine is a practical and effective procedure to decrease severe iron overload in patients with thalassemia major. This study also shows that the combined therapy is associated with an improvement in heart function.

Efficacy and safety of sildenafil in the treatment of severe pulmonary hypertension in patients with hemoglobinopathies

BACKGROUND AND OBJECTIVES

During the last decade new approaches to the treatment of pulmonary arterial hypertension (PH) have increased symptomatic relief and prolonged survival. PH is a common sequel of the hemoglobinopathies, thalassemia and sickle cell anemia, but the use of standard oral treatment options, such as calcium channel blockers, endothelin receptor antagonists, and long-term anticoagulation therapy, is limited because of toxicity and poor effectiveness. Sildenafil citrate is a selective and potent inhibitor of cGMP-specific phosphodiesterase-5 (PDE5) which promotes selective smooth muscle relaxation in lung vasculature and has been utilized successfully in the treatment of PH. The primary objective of this study was to evaluate the efficacy of sildenafil treatment in the control of PH in patients with hemoglobinopathies.

DESIGN AND METHODS

In this study patients with hemoglobinopathies (thalassemia intermedia n=4; thalassemia major n=2; sickle thalassemia n=1) suffering from severe PH were treated with sildenafil citrate (50 mg b.i.d.) for periods ranging from 4 to 48 months.

RESULTS

A significant decrease in pulmonary pressure and improvement in exercise capacity and functional class were observed in all patients. No significant adverse events were reported.

INTERPRETATION AND CONCLUSIONS

These data, in a small group of patients, indicate that sildenafil citrate is effective in the treatment of PH in hemoglobinopathies that cannot be treated with alternative oral drugs and is well tolerated long-term at a daily dose of 100 mg, though studies including more patients may uncover toxicities and limitations of efficacy.

Staphylococcus aureus isolates from patients with Kawasaki disease express high levels of protein A

Kawasaki disease (KD) is an acute vasculitis of young children that can be complicated by coronary artery abnormalities. Recent findings suggest that a superantigen(s) may play an important role in stimulating the immune activation associated with the disease, although the origin of this superantigen(s) is unclear. Staphylococcus aureus, isolated from the rectum or pharynx of patients with KD, secretes toxic shock syndrome toxin 1 (TSST-1). The KD isolates express low levels of other exoproteins compared to isolates from patients with toxic shock syndrome (TSS). Thus, it was previously suggested that the KD isolates may be defective in the global regulatory locus agr (for accessory gene regulator), which positively regulates these factors (D. Y. M. Leung et al., Lancet 342:1385-1388, 1993). Here we describe another characteristic of KD isolates. When considered collectively, the KD isolates were found to express higher levels of staphylococcal protein A than the TSS isolates, another characteristic of an agr-defective phenotype. This correlated with a higher level of spa mRNA in these isolates. In contrast, the KD and TSS isolates expressed comparable levels of TSST-1, consistent with previous findings (D. Y. M. Leung et al., Lancet 342:1385-1388, 1993). Analysis of RNAIII transcript levels and nucleotide sequence analysis of the RNAIII-coding region suggested that the KD isolates are not defective in RNAIII, the effector molecule of the agr regulatory system. However, induction of RNAIII transcription in the KD isolates did not result in a dramatic decrease in the amount of spa mRNA, as has been reported for other strains (F. Vandenesch, J. Kornblum, and R. P. Novick, J. Bacteriol. 173:6313-6320, 1991).

Staphylococcal toxins and protein A differentially induce cytotoxicity and release of tumor necrosis factor-alpha from human keratinocytes

It has been proposed that toxins and other bacterial protein products of Staphylococcus aureus can act as triggers or persistence factors in several inflammatory skin diseases. In this study, we examined the S. aureus isolates from the skin of patients with atopic dermatitis and psoriasis. We found that the bacterial isolates from these patients exhibited either characteristic superantigenic toxins or thermolabile toxins believed to be staphylococcal alpha-toxin. All of these staphylococcal strains also secreted extracellular staphylococcal protein A. We found significant differences in the action of these toxins on human keratinocytes and keratinocyte cell lines. The superantigenic toxins toxic shock syndrome toxin-1, staphylococcal enterotoxins A and B, and exfoliative toxin-A, as well as staphylococcal protein A, did not induce significant cytotoxic damage in the keratinocyte cell line HaCaT, whereas the staphylococcal alpha-toxin produced profound cytotoxicity. Keratinocyte cytotoxicity induced by staphylococcal alpha-toxin was time and concentration dependent and demonstrated the morphologic and functional characteristics of necrosis, not apoptosis. Addition of alpha-toxin to keratinocytes simultaneously induced cell lysis and tumor necrosis factor-alpha release into the medium within 30 min; apparently, it was constitutive tumor necrosis factor-alpha. On the other hand, superantigenic toxins and, in particular, protein A showed stimulation of tumor necrosis factor-alpha secretion in keratinocytes and release of this cytokine after 6-12 h of incubation. Thus, staphylococcal protein A, alpha-toxin, and superantigenic toxins found in S. aureus isolates from patients with psoriasis and atopic dermatitis can produce direct pro-inflammatory effects on keratinocytes through the release of tumor necrosis factor-alpha. We propose that these effects may be relevant to the induction and persistence of lesions in these two diseases.

Presence of IgE antibodies to staphylococcal exotoxins on the skin of patients with atopic dermatitis. Evidence for a new group of allergens

In the current study, we investigated whether Staphylococcus aureus grown from affected skin of atopic dermatitis (AD) patients secreted identifiable toxins that could act as allergens to induce IgE-mediated basophil histamine release. The secreted toxins of S. aureus grown from AD patients were identified by ELISA using antibodies specific for staphylococcal enterotoxin (SE) exfoliative toxin (ET), or toxic shock syndrome toxin (TSST-1). S. aureus isolates from 24 of 42 AD patients secreted identifiable toxins with SEA, SEB, and TSST accounting for 92% of the isolates. 32 of 56 AD sera (57%) tested contained significant levels of IgE primarily to SEA, SEB, and/or TSST. In contrast, although SEA, SEB, or TSST secreting S. aureus could be recovered from the skin of psoriasis patients, their sera did not contain IgE antitoxins. Freshly isolated basophils from 10 AD patients released 5-59% of total histamine in response to SEA, SEB, or TSST-1 but only with toxins to which patients had specific IgE. Basophils from eight other AD patients and six normal controls who had no IgE antitoxin failed to demonstrate toxin-induced basophil histamine release. Stripped basophils sensitized with three AD sera containing IgE to toxin released 15-41% of total basophil histamine only when exposed to the relevant toxin, but not to other toxins. Sensitization of basophils with AD sera lacking IgE antitoxin did not result in release of histamine to any of the toxins tested. These data indicate that a subset of patients with AD mount an IgE response to SEs that can be grown from their skin. These toxins may exacerbate AD by activating mast cells, basophils, and/or other Fc epsilon-receptor bearing cells armed with the relevant IgE antitoxin.