Evidence of a Restrictive Spirometric Pattern in Older Thalassemic Patients

Abstract

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 (D_CO), corrected for both Hb values (D_CO*) and alveolar volume (K_CO), 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, D_CO* and K_CO values, as well as normal endocrinological assessment. By contrast, all those in group C showed a restrictive spirometric pattern with reduced D_CO* (63 ± 8%), elevated K_CO values (120 ± 14%), a variable degree of hypoxia (P_O2 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 D_CO* values, and 2 out of 3 patients had hypogonadism. Considering all patients on the whole, D_CO* 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.

Comparison of pulmonary functions of thalassemic and of healthy children

“…Among the thalassemic subjects, restrictive lung function abnormality was the most common (42/63) observation documented in this study. Our findings are consistent with those of Carnelli et al, 1 Factor et al, 2 Tai et al, 5 Luyt et al, 6 and Filosa et al 7 What is unique to our study is that it was performed exclusively in children, while those studies mentioned earlier were all performed in both children and adults, with a considerably older mean age. Therefore, our study shows that lung dysfunction in thalassemic patients has occurred since childhood.…”

“…However, no correlation was found between serum ferritin levels and any of the lung function values. This finding supported those discovered by Tai et al, 5 and Luyt et al 6 , but contrasted with studies by Carnelli et al, 1 Factor et al, 2 and Filosa et al 7 It is suggested that the duration of iron overload may be more important than the actual amount of iron provided through transfusions. 2 Moreover, serum ferritin levels change during the process of chelation, and do not necessarily reflect total body iron stores.…”

“…On the other hand, most patients in previous studies had regular and adequate chelation therapy but were still found to have lung dysfunction. [1][2][5][6][7]11 This may lead us to question the effectiveness of chelation therapy. Nevertheless, the lung function values observed in our patients were lower than those in other published studies, which may indirectly reflect the benefit of chelation therapy and the role of iron overload.…”

“…There was no correlation between percentage from predicted forced vital capacity and serum ferritin levels, whether in male (r=0.191; P=0.967) or female (r =-0.076, P=0.695) thalassemic subjects. Keywords: pulmonary function, thalassemia, spirometry, serum ferritin level, restrictive lung dysfunction T halassemia refers to a heterogeneous group of heritable hypochromic anemias of various degrees of severity; [1][2][3][4][5][6][7][8][9] it is considered to be the most prevalent genetic disorder in the world. 3 Transfusions of 15-20 ml/kg of packed cells are usually required every 4-5 weeks.…”

Pulmonary Function Abnormalities in Non-Splenectomized and Splenectomized Adult Hemoglobin E/β-Thalassemia Patients and Their Correlation With Pulmonary Hypertension

“…As shown in the studies of Filosa et al 7 and Fung et al, 8 older thalassemia patients with an average age of 19±1.4 years had more RI than younger patients with average age of 10.8±1.7 years and 15.7±1.1 years did. Nevertheless, both SP and NSP in our study were older than those in the previous studies.…”