ABSTRACT
Sickle cell anemia (SCA) causes dysfunction of multiple organs, with pulmonary involvement as a major cause of mortality. Recently, there has been growing interest in the nitrogen single-breath washout (N2SBW) test, which is able to detect ventilation heterogeneity and small airway disease when the results of other pulmonary function tests (PFTs) are still normal. Thus, the objectives of the present study were to assess the heterogeneity in the ventilation distribution in adults with SCA and to determine the association between the ventilation distribution and the clinical, cardiovascular, and radiological findings. This cross-sectional study included 38 adults with SCA who underwent PFTs, echocardiography, computed tomography (CT), and 6-min walk test. To evaluate the ventilation heterogeneity, the patients were categorized according to the phase III slope of the N2SBW (SIIIN2). Compared with adults with lower SIIIN2 values, adults with higher SIIIN2 values showed lower hemoglobin levels (P=0.048), a history of acute chest syndrome (P=0.001), an elevated tricuspid regurgitation velocity (P=0.039), predominance of a reticular pattern in the CT (P=0.002), a shorter 6-min walking distance (6MWD) (P=0.002), and lower peripheral oxygen saturation (SpO2) after exercise (P=0.03). SIIIN2 values correlated significantly with hemoglobin (rs=-0.344; P=0.034), forced vital capacity (rs=-0.671; P<0.0001), diffusing capacity for carbon monoxide (rs=-0.376; P=0.019), 6MWD (rs=-0.554; P=0.0003), and SpO2 after exercise (P=0.040). Heterogeneity in the ventilation distribution is one of the most common pulmonary dysfunctions in adults with SCA. Moreover, relationships exist between ventilation heterogeneity, worsening of pulmonary structural damage, and reduced tolerance for exercise.
Subject(s)
Anemia, Sickle Cell/physiopathology , Exercise Tolerance/physiology , Lung/physiopathology , Adult , Breath Tests , Cross-Sectional Studies , Echocardiography , Female , Humans , Male , Nitrogen , Respiratory Function Tests , Tomography, X-Ray Computed , Walk Test , Young AdultABSTRACT
The development of acute megakaryoblastic leukemia (ANLL-M7) following myelodysplastic syndrome (MDS) has been described only in a few reports, and the mutations necessary for this transformation are still unknown. In this study, we describe a case of ANLL-M7 with a previous history of MDS presenting a complex karyotype 46,XX, t(4;11)(q21;q23),del(5)(q13q33),t(12;13)(p13;q21) and N-RAS point mutation. During MDS, the patient showed a hypercellular myelogram with dysplasia of the three myeloid lineages and the clinical symptoms characteristic of the 5q- syndrome. During the follow-up, we observed the appearance of two additional subclones, one with an isochromosome 17q and another with polyploidy. The presence of an isochromosome 17q in one subclone and polyploidy in another is probably due to the genetic instability generated by the malignant transformation.
