Lungs in thalassaemia major patients receiving regular transfusion

Pulmonary and renal long COVID at two-year revisit

This study investigated host responses to long COVID by following up with 89 of the original 144 cohorts for 1-year (N = 73) and 2-year visits (N = 57). Pulmonary long COVID, characterized by fibrous stripes, was observed in 8.7% and 17.8% of patients at the 1-year and 2-year revisits, respectively, while renal long COVID was present in 15.2% and 23.9% of patients, respectively. Pulmonary and renal long COVID at 1-year revisit was predicted using a machine learning model based on clinical and multi-omics data collected during the first month of the disease with an accuracy of 87.5%. Proteomics revealed that lung fibrous stripes were associated with consistent down-regulation of surfactant-associated protein B in the sera, while renal long COVID could be linked to the inhibition of urinary protein expression. This study provides a longitudinal view of the clinical and molecular landscape of COVID-19 and presents a predictive model for pulmonary and renal long COVID.

Pulmonary dysfunction in thalassaemia major: is there any relationship with body iron stores?

Although pulmonary function abnormalities in thalassaemia major (TM) were described in 1980, the pathogenetic mechanism is not clear and data are contradictory, probably because of study heterogeneity and the multifactorial nature of the pathogenesis. We retrospectively analysed 73 adult TM patients to evaluate the prevalence of pulmonary dysfunction in adult TM and investigate relationships with iron load. All patients underwent body plethysmography and carbon monoxide diffusion (DLCO) was assessed in 63, in addition to blood tests, echocardiogram and T2* myocardial and liver magnetic resonance imaging. Restrictive lung disease was present in 26 (35·6%) patients. Serum ferritin levels were higher in patients with restrictive pattern (1526 μg/l vs. 975 μg/l, P = 0·05). Restrictive lung disease did not correlate with cardiac or liver iron overload. However, considering only patients with serum ferritin >2500 μg/l, those with restrictive pattern also had heart (T2* 14·28 ± 9·99 ms vs. 31·59 ± 7·43 ms) and liver iron overload (LIC 16·02 ± 8·44 mg vs. 5·02 ± 2·69 mg Fe/g dry weight) compared to those without restrictive pattern. Twenty-five patients (39·7%) had decreased DLCO. No correlation was observed with iron parameters. In our data restrictive pattern was predominant; we observed a relationship with serum ferritin levels suggesting that iron, particularly its chronic effect, could play a role in the pathogenesis of pulmonary disease.

Pulmonary Functions in Children With Thalassemia Major

BACKGROUND

Thalassemia major (TM) is a chronic disease requiring regular transfusions that may result in generalized iron loading, such as in the heart, the liver, endocrine organs, and the lungs. We aimed to determine pulmonary function abnormalities in children with TM in our center.

PATIENTS AND METHODS

In this study, pulmonary function tests (PFTs) of 49 patients with TM who received regular blood transfusion and had no history of chronic respiratory disease were evaluated. The relationship between PFTs and the age, the body surface area, pretransfusional hemoglobin, and serum ferritin was evaluated.

RESULTS

Among the β-TM patients included in this study, 61% were male and 39% were female, with a mean age of 10.8±3 years (range, 5 to 17 y). The patients' mean level of ferritin was 3873±2011 ng/dL (range, 676 to 9476 ng/dL). A reduced forced vital capacity (FVC) was found in 33 patients (67%). A reduced forced expiratory volume in 1 second (FEV1) was found in 15 patients (30%). A forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) ratio of >80% was found in all patients. The peak expiratory flow (PEF) was decreased in 23 patients (46.9%). The forced mid-expiratory flow between 25% and 75% of the exhaled vital capacity (MEF25%-75%) was decreased in 5 patients (10%). FVC and FEV1 values in patients with a high ferritin level (>2500 ng/dL) were decreased compared with patients with a low ferritin level (<2500 ng/dL) (P=0.04, 0.03). FVC, FEV1, and PEF parameters were negatively correlated with the age and the body surface area. Age was a predictor of FVC (β=-0.450, P<0.001), FEV1 (β=-0.419, P<0.001), and PEF (β=-0.505, P<0.001), and hemoglobin was a predictor of FEV1/FVC (β=0.366, P=0.01) and MEF25%-75% (β=0.323, P=0.003).

CONCLUSIONS

Our results concluded that the respiratory system should be evaluated by PFTs even in asymptomatic patients with high serum ferritin levels during the adolescent period annually to prevent the squeal of pulmonary disease in TM. Patients who have abnormal PFTs should be reevaluated for compliance with chelation therapy and the transfusion program.

Effect of long-term transfusion therapy on the glycometabolic status and pancreatic Beta cell function in patients with Beta thalassemia major

BACKGROUND

Diabetes mellitus is a major complication of iron overload in patients with beta thalassemia major.

DESIGN

This is a descriptive study conducted in a Tertiary Care Teaching Hospital to analyze beta cell function and insulin resistance, and their relation to iron overload status in beta thalassemia major. Fasting glucose, two-hour post load glucose, fasting insulin, alanine amino transaminase (ALT), and ferritin were used as outcome measures. The homeostatic model assessment (HOMA model) was used to calculate the beta cell function and insulin resistance index.

RESULTS

Of the 30 cases, 20% had impaired fasting glucose, 3.3% had impaired glucose tolerance, and none had diabetes. Fasting glucose was not significant between the cases and controls (P = 0.113). Fasting insulin (P = 0.001), ferritin (P = 0.001), and ALT (P = 0.001) levels were significantly high in the cases. Insulin resistance index was significantly higher in the cases (P = 0.001) as also the beta cell function (P = 0.001). With increase in age and the number of units transfused there is a decline in beta cell function, fasting insulin, and insulin resistance after attaining the maximum level. This suggests that initial insulin resistance is followed by insulin depletion due to loss of beta cell function, leading to diabetes mellitus.

CONCLUSION

Impaired glucose tolerance (IGT) and insulin resistance precede the onset of insulin-dependent diabetes and adequate chelation therapy is essential for delaying the onset or for prevention of diabetes.

Effect of using bedside leukocyte filter on pulmonary functions in patients with thalassemia major

In settings of limited health resources, using leukocyte-filtered blood is limited to patients with leukocyte-mediated complications. The aim of this study was to determine the patterns of lung dysfunction among patients with β-thalassemia major (BTM) after the application of the leukostop filter during transfusion for a period of 6 months. The study included 30 patients with transfusion-dependent BTM divided into two groups according to the use of leukocyte filter. Group I included 15 patients with BTM allocated to use the leukocyte filter before each blood transfusion for 6 months and group II included 15 patients with BTM using nonleukocyte-filtered blood. Patients with history of airway disease and smokers were excluded. Chest X-ray and pulmonary function tests (PFT) using spirometry were done for each patient at baseline and after the use of the leukocyte filter for 6 months. No significant difference was found at baseline PFTs in both groups, the distribution of obstructive pulmonary disease significantly improved in group I in the postfilter evaluation, P < 0.05, however no change in pulmonary disease distribution in group II. A statistical significance improvement in forced vital capacity (FVC), forced expiratory volume in 1st second (FEV1) and FEV1/FVC in postfilter evaluation, while in group II a decline in FEV1, FVC, and no significant change in FEV1/FVC ratio. There was no correlation between serum ferritin and PFT results.

CONCLUSION

Pulmonary function abnormalities, although subclinical is not an infrequent finding in patients with BTM; leukofiltred blood may improve PFT.

Cardiac and pulmonary dysfunction in asymptomatic beta-thalassanemia major

This study assessed cardiac and pulmonary dysfunction in 26 asymptomatic patients with beta-thalassemia major. This investigation was a case-controlled study considering 10-20-year-old patients with beta-thalassemia major and no cardiac or pulmonary symptoms. Healthy individuals matched for age and sex were used as controls. At 48-72 h after blood transfusion, the patients underwent echocardiography and spirometry by a cardiologist and a pulmonologist. The results were compared to those of the control group. The right and left myocardial performance index, preejection period/ejection time ratio, ejection fraction, acceleration time, isovolumic contraction time, and bilateral isovolumic relaxation times in the study group demonstrated significant differences from the data of the controls. Right deceleration time was significantly different between the 2 groups. Myocardial performance index, peak early velocity of the right heart, and peak atrial velocity-to-peak early velocity ratio of the right side by Doppler tissue imaging were also significantly different between the 2 groups. Spirometry showed a significant difference in forced expiratory volume in 1 s/forced vital capacity between groups. Based on spirometry, pulmonary involvement in the patients was 77% restrictive. These findings show that systolic and diastolic dysfunction of the heart and pulmonary disturbances are unavoidable in patients with beta-thalassemia major.

Exercise performance in thalassemia major: correlation with cardiac iron burden

Exercise performance is decreased in patients with Thalassemia major (TM), but the relative impact of anemia and iron overload on exercise capacity is unknown. We assessed the cardiopulmonary function of 71, well-transfused TM patients via graded treadmill exercise stress test. All patients underwent MRI of the heart, pancreas, and liver and diagnostic phlebotomy. Patients ranged in age from 13 to 46 years of age. Fifteen patients were excluded from analysis due to submaximal effort. Mean Vo2 max was 83.0% of predicted and was limited by abnormal cardiovascular mechanisms, consisting of a decreased O2 pulse (86.6% of predicted) in men and decreased maximum heart rate (HR) response (85% of predicted) in women. Patients with hemoglobin less than 12 g/dL had lower O2 pulse and Vo2 max, regardless of sex. Cardiac iron was negatively associated with maximum HR response and Vo2 max (r2 = 0.10 and 0.08, respectively, P < 0.05). Vo2 max was correlated with cardiac R2*, hs-CRP, sex and hemoglobin in decreasing strength of association. In thalassemia, exercise performance is limited by impaired stroke-volume reserve in men and blunted HR response in women. Iron toxicity may be mediated through vascular inflammation and direct modulation of HR response to exercise.

Restrictive pulmonary dysfunction and its predictors in young patients with β-thalassaemia major

BACKGROUND

Pulmonary dysfunction represents one of the most undervalued and less recognized complications in patients with β-thalassaemia.

OBJECTIVES

The aim of this study was to assess the pattern of pulmonary dysfunction and consequently to investigate possible associated factors that might contribute to lung impairment in young patients with β-thalassaemia major.

METHODS

Fifty-two children and young adults (mean age: 21.33 ± 6.24 years) with β-thalassaemia major on conventional treatment (transfusions and iron chelation therapy) were included in the study. A complete computerized pulmonary function testing (PFT) system for recording pulmonary diffusion capacity and simultaneous determination of alveolar volume and pulmonary volumes was equipped.

RESULTS

Results showed that 20 patients (38.46%) had restrictive pulmonary pattern that was preferentially observed in older and shorter patients. Serum ferritin levels were higher in the restrictive group (2,096 ± 1,831 ng/dl) compared to patients with normal pulmonary function (1,354 ± 942 ng/dl) (P = 0.066). Diffusional impairment characterized by significantly lower DLCO*% values, was observed in the restrictive group (P = 0.004), implicating the 62.5% of the population studied. Paired linear correlations showed that age was negatively correlated to DLCO*% (r = -0.548, P < 0.001) and SaO(2) % (r = -0.789, P < 0.001) and with most of the pulmonary functional parameters that determine a restrictive. Multivariate regression analysis identified age as the major predictor for restrictive pulmonopathy followed by serum ferritin levels.

CONCLUSIONS

Our study shows that pulmonary impairment is shown in a great proportion even among asymptomatic young thalassaemic patients, thus, regular screening of pulmonary function should be adopted in the routine clinical follow up of these patients.

Pulmonary function in thalassaemia major and its correlation with body iron stores

This study compared pulmonary function tests (PFTs) with cardiac, pancreatic and liver iron in 76 thalassemia major (TM) patients. Restrictive lung disease was observed in 16%, hyperinflation in 32% and abnormal diffusing capacity in 3%. While no patients met Global Initiative for Chronic Lung Disease criteria for airways obstruction, there were indicators of small airways disease and air trapping. PFTs did not correlate with somatic iron burden, blood counts or haemolysis. Restrictive lung disease was associated with inflammation. We conclude that TM patients have pulmonary abnormalities consistent with small airways obstruction. Restrictive disease and impaired diffusion are less common.

Pulmonary function test in transfusion-dependent β-thalassemia major patients: a pilot study

Lung involvement is one of known complications of thalassemia. The aim of this study was to determine predominant type of pulmonary dysfunction and its relationship to iron overload in β-thalassemia children. Fifty thalassemia major children with treatment of regular blood transfusion and desferrioxamine participated in the study. Thirty-three boys and 17 girls (median age 12.5 years) with β-thalassemia enrolled in the study. Other information including body mass index, hematocrit, and the number of years of blood transfusion were recorded. Serum ferritin level and hematocrit were 3346 ± 1667 mg/dL and 27.7 ± 2, respectively. Pulmonary function tests were performed in all subjects for detecting pulmonary dysfunction. Thirty-five patients (70%) with thalassemia had abnormal result of spirometry. Obstructive airway disease based on reduced forced expiratory volume in 1 second (FEV(1)) and FEV(1)/forced vital capacity (FVC) ratio <80% was detected in 4 patients (8%). Six patients (12%) showed restrictive pattern, as defined by a reduction FVC <80% and FEV(1)/FVC ratio ≥80%. In this study, small airway involvement based on presence of forced expiratory flow (FEF(25%-75%)) <60%, FEV(1)/FVC ratio >70%, and FVC >80% was detected in 25 subjects (50%). Decreased values of peak expiratory flow rate (PEF) were detected in 23 (46%) and low FEV(1) in 10 (20%) subjects. There was no significant correlation between abnormal pulmonary function test and serum ferritin level in children with thalassemia. This study showed small airway disease was predominant abnormality in thalassemia patients, although additional larger studies are needed to evaluate underlying mechanisms and validate these findings.

A multivariate analysis of serum nutrient levels and lung function

Background

There is mounting evidence that estimates of intakes of a range of dietary nutrients are related to both lung function level and rate of decline, but far less evidence on the relation between lung function and objective measures of serum levels of individual nutrients. The aim of this study was to conduct a comprehensive examination of the independent associations of a wide range of serum markers of nutritional status with lung function, measured as the one-second forced expiratory volume (FEV₁).

Methods

Using data from the Third National Health and Nutrition Examination Survey, a US population-based cross-sectional study, we investigated the relation between 21 serum markers of potentially relevant nutrients and FEV₁, with adjustment for potential confounding factors. Systematic approaches were used to guide the analysis.

Results

In a mutually adjusted model, higher serum levels of antioxidant vitamins (vitamin A, beta-cryptoxanthin, vitamin C, vitamin E), selenium, normalized calcium, chloride, and iron were independently associated with higher levels of FEV₁. Higher concentrations of potassium and sodium were associated with lower FEV₁.

Conclusion

Maintaining higher serum concentrations of dietary antioxidant vitamins and selenium is potentially beneficial to lung health. In addition other novel associations found in this study merit further investigation.

Pulmonary function test in transfusion-dependent beta-thalassemia patients

Beta-thalassaemia is the most common hemoglobinopathies in our region with treatment of regular blood transfusion. Iron overload and hemosiderosis can cause organ involvement. Recent studies have focused on pulmonary involvement and pathophysiology of lung damage. The goal of this study was to investigate the pulmonary abnormalities in thalassemic patients in relation with sign and symptoms and iron overload. The authors studied pulmonary function test (PFT) at the Adult Thalassemia Clinic in Tehran. The history of blood transfusion, iron chelation, respiratory problems, and drug usage was taken. Physical examination, PFT, arterial blood gas (ABG), and chest X-ray (CXR) were done. In total, 139 patients were studied. The mean age was 21.1 years and mean duration of transfusion was 18 years. It was found that 133 patients (95.7%) did not have respiratory problems and only 6 (4.3%) had some respiratory complaints. In CXR, 100 patients (89.3%) had normal lung pattern and others (10.7%) had variable degrees of abnormal lung pattern. In ABG, mean of Po(2) was 73.5% and mean of O(2) saturation was 90.6%. In PFT, 101 patients (72.7%) had restrictive pattern, 35 (25.1%) had normal pattern, and 3 (2.2%) had combined pattern. According to vital capacity, the patients were placed in five categories: 54 patients (38.8%) normal, 37 (26.6%) mild, 35 (25.3%) moderate, 10 (7.2%) severe, and 3 (2.1%) extremely severe pulmonary deficit. There was no statistical significance between PFT results with all variables studied, except duration of blood transfusion, which may be considered a indirect effect of iron load (p = .05, r = .361). According to these results, restrictive pattern was the most common finding (72.7%) in PFT, while 95.7% of patients had no respiratory complaint, and in the chest X-ray group, 89.3% had normal pattern. The authors conclude that the lung may be considered a site for organ damage, and alteration of pulmonary function may be expected in transfusion-dependent patients in spite of no pulmonary symptoms or normal CXR. In recent years, because of new iron chelating drugs, doctors can expect thalassemic patients to have a long life-time and need to increase their quality of life. One way to do this is to evaluate the respiratory system by PFT to prevent the squeal of pulmonary disease.

Pulmonary function tests in children with beta-thalassemia major

Lung function abnormality is a known complication of thalassemia, but the results of studies in pulmonary function have been inconsistent. This study was conducted to describe the type of lung impairment in thalassemic children. Pulmonary function tests were conducted in 40 children with beta-thalassemia major, 23 males and 17 females. Tests included spirometry, total lung capacity (TLC), single breath diffusing capacity of the lung for carbon monoxide (DL(CO)) and arterial blood gases. Serum ferritin level was measured in all children to study its relationship to lung function impairment. A predominantly restrictive pattern was seen in 14 patients (35%). These patients had a significant reduction in RV, FVC, TLC and PEF with an FEV1/FVC ratio of more than 75%. Obstructive airway disease was found in six patients (15%), with an FEV1/FVC ratio less than 75%, increased RV and reduced FEF(25%-75%). Impairment of diffusion was found in 10 patients (25%), with DL(CO) reduced to less than 80% of the predicted value. Arterial blood gases results showed that no patient was hypoxic. No correlation was found between the severity of restrictive or obstructive disease and the serum ferritin level. There was a significant linear correlation between age and serum ferritin level (P < 0.019). Patients with thalassemia have a predominantly restrictive lung dysfunction pattern. This may be due to pulmonary parenchymal pathology, although the reason for the obstructive pattern seen in a small proportion of patients remains obscure.

Study of pulmonary function tests in thalassemic children

The present study aimed to investigate pulmonary function tests (PFTs) in children with thalassemia and to assess the relation between the degree respiratory impairment with the body iron status. High resolution computed tomography of chest (CHRCT) and bronchoalveolar lavage (BAL) was performed to study the cause of pulmonary dysfunction. Thirty-one children with thalassemia over 8 years were included. PFTs were studied including lung volumes and carbon monoxide diffusion capacity (DLco). Patients with abnormal PFTs and/or impaired DLco were further subjected to CHRCT and BAL. Total cell count was measured; differential count was performed on Giemsa and PAP smears. Iron laden macrophages were identified on Perl's stain. PFTs were normal in 51.61%, diffusion capacity impaired in 41.16%, restriction in 16.12%, while obstruction in 3.22% of cases, respectively. There was significant inverse correlation between DLco and serum ferritin. Through multivariate regression analysis, ferritin was found to be a strong predictor for forced vital capacity and total lung capacity. Bronchial dilatation and areas of air trapping were the predominant CHRCT findings. Iron laden macrophages were demonstrated in 14 of 15 patients in BAL. A significant correlation between serum ferritin and DLco, forced vital capacity, total lung capacity, and the presence of iron laden macrophages in BAL indicates that iron plays a major role in the etiopathogenesis of these abnormalities.

Chronic sickle cell lung disease: new insights into the diagnosis, pathogenesis and treatment of pulmonary hypertension

Pulmonary hypertension is a common complication of sickle cell disease (SCD). In spite of the mild elevations in pulmonary artery pressures in these patients, the associated morbidity and mortality is high. In fact, in adult patients with SCD, pulmonary hypertension is emerging as the major independent risk factor for death. The aetiology of pulmonary hypertension is probably multifactorial, including haemolysis, impaired nitric oxide bioavailability, chronic hypoxaemia, thromboembolism, parenchymal and vascular injury because of sequestration of sickle erythrocytes, chronic liver disease and asplenia. Interestingly, pulmonary hypertension is emerging as a common, and probably, invariant sequella of lifelong haemolytic anaemia in other hereditary and acquired haemolytic diseases, such as thalassaemia, stomatocytosis and spherocytosis. There are currently limited specific data on the effects of any treatment modality for pulmonary hypertension in patients with SCD. It is likely that maximization of SCD therapy, in all patients, and treatment with selective pulmonary vasodilators and antiproliferative agents, in patients with severe disease, would be beneficial. A large trial evaluating the effects of therapy for pulmonary hypertension in the SCD population is clearly indicated.

Cardiopulmonary complications of sickle cell disease: role of nitric oxide and hemolytic anemia

Medical advances in the management of patients with sickle cell disease, thalassemia, and other hemolytic anemias have led to significant increases in life expectancy. Improved public health, neonatal screening, parental and patient education, advances in red cell transfusion medicine, iron chelation therapy, penicillin prophylaxis for children, pneumococcal immunization, and hydroxyurea therapy have all likely contributed to this effect on longevity. Importantly, as a generation of patients with sickle cell disease and thalassemia ages, new chronic complications of these hemoglobinopathies develop. In this context, pulmonary hypertension is emerging as one of the leading causes of morbidity and mortality in adult sickle cell and thalassemia patients, and likely in patients with other hemolytic anemias. A common feature of both sickle cell disease and thalassemia is intravascular hemolysis and chronic anemia. Recent data suggest that chronic intravascular hemolysis is associated with a state of endothelial dysfunction characterized by reduced nitric oxide (NO) bioavailability, pro-oxidant and pro-inflammatory stress and coagulopathy, leading to vasomotor instability and ultimately producing a proliferative vasculopathy, a hallmark of which is the development of pulmonary hypertension in adulthood. In conclusion, pulmonary hypertension is common in patients with hereditary hemolytic anemias and is associated with a high risk of death in patients with sickle cell disease. New therapies targeting this vasculopathy and aimed at normalizing the vasodilator:vasoconstrictor balance are discussed.

β-Thalassemia Major: Thin-Section CT Features and Correlation with Pulmonary Function and Iron Overload

PURPOSE

To describe and quantify thin-section computed tomographic (CT) features of the lung in patients with beta-thalassemia major (beta-TM) and determine the correlation between thin-section CT findings, pulmonary function test (PFT) results, and iron overload.

MATERIALS AND METHODS

Forty-one patients with beta-TM (mean age, 24.5 years) underwent thin-section CT (during full inspiration and expiration) and PFTs. Two radiologists in consensus recorded the presence of focal bronchial and parenchymal abnormalities and air trapping. A semiquantitative air trapping score (ATS) was used, and patients were separated into air trapping-negative (ATS between 0 and 3) and air trapping-positive (ATS > 3) groups for statistical analysis. Iron overload was estimated by calculating the ratio of the signal intensity (SI) of the liver to the SI of paraspinous muscle by using magnetic resonance imaging in 27 patients (66%). We performed multiple logistic regression analysis to study the influence of age, PFT findings, and SI ratio on the presence of air trapping at CT and multivariate regression analysis to study the simultaneous influence of the presence of air trapping on obstructive PFT indexes.

RESULTS

Air trapping was the predominant thin-section CT finding and was seen in 10 (24%) of 41 patients. No patient had interstitial lung disease at CT, although 11 (27%) had a restrictive spirometric pattern. Simple logistic regression analysis revealed significant associations between ATS and forced expiratory volume in the first second (FEV1), FEV1/forced vital capacity (FVC), forced expiratory flow (FEF) in the midexpiratory phase (FEF25%-75%), FEF at 50% of the FVC (FEF50%), and FEF at 75% of the FVC (FEF75%) (P =.019,.030,.007,.034, and.021, respectively) but not between ATS and SI ratio. At multiple logistic regression analysis, only FEF25%-75% was significantly associated with ATS (P =.019, adjusted odds ratio = 0.86, R2 = 41.8%). Multivariate analysis revealed that ATS did not have a significant influence on lung function indexes (P =.104), although significant effects were found with FEV1, FEF25%-75%, FEF50%, and FEF75% when examined separately.

CONCLUSION

Air trapping may be present at expiratory thin-section CT in patients with beta-TM and is associated with reduced FEF25%-75% values but not hepatic iron overload.

Pulmonary dysfunction in transfusion-dependent patients with thalassemia major

Pulmonary function tests were performed on 62 transfusion-dependent patients with thalassemia major, ranging in age from 8 to 33 years, and receiving chelation therapy with desferrioxamine or deferiprone. Percent predicted values for FVC, FEV1, and PEF were significantly reduced, whereas FEV1/FVC and maximal expiratory flow at 25% FVC were within normal limits, indicating a restrictive disease. Both FVC and FEV1 were negatively correlated with transfusional iron burden as indexed by age. Single-breath carbon monoxide transfer factor was reduced, even after correction for low hemoglobin concentration, and was negatively correlated with iron burden and iron overload, as indexed by serum ferritin levels. Owing to low hemoglobin concentration, blood-diffusing capacity was reduced, in spite of increased lung capillary blood volume, which was, however, adequate to normalize blood diffusing capacity when hemoglobin concentration was only partially restored by transfusion. The diffusing capacity of the alveolar-capillary membrane was substantially decreased and negatively correlated with age and serum ferritin, the fall being primarily attributed to increased membrane thickness. These findings suggest that lung fibrosis and/or interstitial edema related to iron overload are the main cause of pulmonary dysfunction observed in patients with thalassemia major.

Respiratory function in patients with thalassaemia major: relation with iron overload

AIMS

(1) To determine the pattern of respiratory impairment in children with thalassaemia major (TM); (2) to assess the relation between the degree of respiratory impairment and total body iron content.

METHODS

Twenty nine TM patients were recruited. All underwent physical examination, standardised pulmonary function tests (spirometry, lung volume, and single breath diffusion capacity for carbon monoxide), and magnetic resonance imaging measurements of the liver. Serum ferritin was measured. The signal intensity ratio of liver to that of paraspinal muscle (T1 weighted sequence) and serum ferritin were used as surrogate index of body iron content.

RESULTS

Sixteen boys and 13 girls (median age 14.2 years) were studied. None had clinical evidence of congestive heart failure. Sixteen had normal lung function. Impairment of diffusion capacity (median DL(co) 83.5% predicted) was the most common abnormality, being observed in 34% of patients. Pure restrictive and obstructive ventilatory impairment was found in one and two patients respectively. Five patients had a combination of ventilation and diffusion defects. There was no correlation between the degree of impairment of each respiratory abnormality and body iron content.

CONCLUSION

Diffusion impairment was the commonest abnormality found in our cohort of paediatric TM patients. Our data did not support the notion that respiratory function impairment was correlated with body iron content.

Pulmonary iron overload in thalassemia major presenting as small airway disease

Lung function abnormalities that are associated with thalassemia major are variable with etiology that is yet undetermined. Some studies have suggested that pulmonary iron deposition is a probable cause for these lung defects although there has been no antemortem histopathological and radiological evidence for this. We report a case of thalassemia major with biopsy-proven pulmonary iron overload, in which thoracic high-resolution computed tomography revealed a morphological-functional correlation consistent with small airway disease.

Evidence of a restrictive spirometric pattern in older thalassemic patients

BACKGROUND

Lung impairment represents one of the complications of thalassemia major whose clinical picture can remain in subclinical form all life long. Few works have been published and the results are contradictory.

OBJECTIVES

The aim of this study was to determine the spirometric pattern, the age of onset in thalassemic boys and girls, and to investigate the association with the onset of endocrinological complications.

METHODS

We studied 48 patients, divided into three groups according to pubertal stages, in order to better distinguish the periods of life in which different endocrinological complications usually appear. Group A: (n = 14; 8 F, 6 M; age 10.8 +/- 1.7 years): prepubertal patients; group B (n = 21; 10 F, 11 M; age 15.7 +/- 1.1 years): pubertal patients; and group C (n = 13; 9 F, 4 M; age 19.0 +/- 1.4 years): postpubertal patients. Pulmonary function tests (PFTs) and diffusing capacity for carbon monoxide (DCO), corrected for both Hb values (DCO*) and alveolar volume (KCO), were performed 2 days after blood transfusion and were considered pathologic when they fell below 80% of the predicted value.

RESULTS

All patients in group A showed normal PFTs, DCO* and KCO values, as well as normal endocrinological assessment. By contrast, all those in group C showed a restrictive spirometric pattern with reduced DCO* (63 +/- 8%), elevated KCO values (120 +/- 14%), a variable degree of hypoxia (PO2 82 +/- 9%), and high serum ferritin levels. Only 2 patients showed a radiological picture of interstitial fibrosis. Furthermore, 9 patients had hypogonadism and 3 hypothyroidism. In group B, only 3 patients showed a restrictive pattern and 1 of them reduced DCO* values, and 2 out of 3 patients had hypogonadism. Considering all patients on the whole, DCO* was negatively correlated with both serum ferritin (r = -0.58; p < 0.05) and age (r = -0.57; p < 0.05).

CONCLUSIONS

The presence of a restrictive pattern in 16 older patients associated with both high serum ferritin levels and endocrinological complications in a lot of them was the main feature in this study. Iron overload might be the main factor determining lung impairment, even though a more accurate evaluation is necessary. Possible pathological mechanisms and the role of the genotype are discussed.

Secondary iron overload

Transfusion therapy for inherited anemias and acquired refractory anemias both improves the quality of life and prolongs survival. A consequence of chronic transfusion therapy is secondary iron overload, which adversely affects the function of the heart, the liver and other organs. This session will review the use of iron chelating agents in the management of transfusion-induced secondary iron overload. In Section I Dr. John Porter describes techniques for the administration of deferoxamine that exploit the pharmacokinetic properties of the drug and minimize potential toxic side effects. The experience with chelation therapy in patients with thalassemia and sickle cell disease will be reviewed and guidelines will be suggested for chelation therapy of chronically transfused adults with refractory anemias. In Section II Dr. Nancy Olivieri examines the clinical consequences of transfusion-induced secondary iron overload and suggests criteria useful in determining the optimal timing of the initiation of chelation therapy. Finally, Dr. Olivieri discusses the clinical trials evaluating orally administered iron chelators.

Evidence of lymphocyte alveolitis by bronchoalveolar lavage in thalassemic patients with pulmonary dysfunction

Pulmonary dysfunction represents one of the least studied complications in thalassemic patients. Probably, it is due to the absence of pulmonary symptoms. There are few works in the literature, and contradictory results have been published. The aim of this study was to define the spirometric pattern and the possible causes of lung impairment by testing bronchoalveolar lavage (BAL) with pathological pulmonary function tests (PFTs). Furthermore, diffusion capacity tests for carbon monoxide corrected for hemoglobin value (Dco*) were performed. We studied 48 thalassemic patients (27 F and 21 M), with an age range from 8 to 23 years, divided into two groups on the basis of PFTs results. Thus, group A was formed by 16 patients with restrictive spirometric patterns of whom 14 had also reduced Dco* values and group B consisted of 32 patients with normal PFTs and Dco* values. Patients of group A underwent chest high-resolution computing tomography (CHRCT) and BAL whose fluid was analyzed by microbiologic and cytological assays. A pathological CHRCT picture was present in 8 patients. Nine out of 16 patients who accepted to undergo BAL had a chronological age greater than 17 years with a mean bone age of 13.9 years. BAL results showed lymphocyte alveolitis in 6 patients and a normal cytogram in 3, while alveolar iron-laden macrophages were present in 4 out of 6 patients with alveolitis and 2 out of 3 patients with normal cytogram. Moreover, all examined BAL fluids showed a normal CD4/CD8 ratio, while only 2 patients showed an altered serum CD4/CD8 ratio. We demonstrated the presence of (1) lung-restrictive syndrome in 16 of the oldest thalassemic patients; (2) lymphocyte alveolitis in 6 patients, and (3) a picture of interstitial fibrosis by CHRCT in 8 of them. All these data are suggestive of a diagnosis of interstitial lung disease secondary to thalassemia. BAL helped to identify the presence of alveolar iron-laden macrophages that represented a local defense mechanism against free iron. This latter finding therefore might be the primary cause of the lung impairment promoting an oxidative damage. Further studies are needed to investigate this hypothesis and therapeutical potentials.