Polymorphisms in Inflammatory Genes Modulate Clinical Complications in Patients With Sickle Cell Disease.

Sickle cell disease (SCD), the most common monogenic disease worldwide, is marked by a phenotypic variability that is, to date, only partially understood. Because inflammation plays a major role in SCD pathophysiology, we hypothesized that single nucleotide polymorphisms (SNP) in genes encoding functionally important inflammatory proteins might modulate the occurrence of SCD complications. We assessed the association between 20 SNPs in genes encoding Toll-like receptors (TLR), NK cell receptors (NKG), histocompatibility leukocyte antigens (HLA), major histocompatibility complex class I polypeptide-related sequence A (MICA) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), and the occurrence of six SCD clinical complications (stroke, acute chest syndrome (ACS), leg ulcers, cholelithiasis, osteonecrosis, or retinopathy). This study was performed in a cohort of 500 patients. We found that the TLR2 rs4696480 TA, TLR2 rs3804099 CC, and HLA-G, rs9380142 AA genotypes were more frequent in patients who had fewer complications. Also, in logistic regression, the HLA-G rs9380142 G allele increased the risk of cholelithiasis (AG vs. AA, OR 1.57, 95%CI 1.16-2.15; GG vs. AA, OR 2.47, 95%CI 1.34-4.64; P = 0.02). For SNPs located in the NKG2D loci, in logistic regression, the A allele in three SNPs was associated with a lower frequency of retinopathy, namely, rs2246809 (AA vs. GG: OR 0.22, 95%CI 0.09-0.50; AG vs. GG: OR 0.47, 95%CI 0.31-0.71; P = 0.004, for patients of same origin), rs2617160 (AT vs. TT: OR 0.67, 95%CI 0.48-0.92; AA vs. TT: OR 0.45, 95%CI 0.23-0.84; P = 0.04), and rs2617169 (AA vs. TT: OR 0.33, 95%CI 0.13-0.82; AT vs. TT: OR 0.58, 95%CI 0.36-0.91, P = 0.049, in patients of same SCD genotype). These results, by uncovering susceptibility to, or protection against SCD complications, might contribute to a better understanding of the inflammatory pathways involved in SCD manifestations and to pave the way for the discovery of biomarkers that predict disease severity, which would improve SCD management.

Clinical relevance of pulmonary vasculature involvement in sickle cell disease.

Pulmonary complications are frequent in patients with sickle cell disease (SCD), but few studies have described lung pathology in SCD. We studied the lung tissue of 30 deceased SCD patients (1994-2012). Demographics, genotype, clinical characteristics, cause of death and associated conditions are presented. We quantified the presence of pulmonary arterial changes, thrombosis and venous thickening. Alveolar capillary abnormalities were demonstrated using CD34 expression and confocal microscopy. Autopsy and echocardiography reports were reviewed to classify heart abnormalities. Tissue expression of markers of endothelial activation (vascular cell adhesion molecule 1, intercellular adhesion molecule 1 and vascular endothelial growth factor) was quantified in pulmonary vessels. Median age was 33 years; genotype was SS in 19, SC in 7 and Sß in 4, and there were 18 males. Hypertensive arterial changes were present in 76% of the patients, recent thrombosis in 80% and old thrombosis in 43%. Venous thickening was present in 23% and pulmonary capillary haemangiomatosis foci in 87%. Ten percent of the patients presented right ventricular hypertrophy. There was no increased expression of endothelial activation markers when compared to controls. SCD affects the whole pulmonary vascular tree and reflects the multiple burden on lung vasculature imposed by the disease upon time.

Complicações cardiopulmonares das doenças falciformes / Cardiopulmonary complications of sickle cell disease

O pulmão é um dos principais alvos de complicações agudas e crônicas nas doenças falciformes (DF). A síndrome torácica aguda é a segunda causa de internação hospitalar apresentando considerável morbimortalidade. O suporte clínico de alta qualidade é a base do tratamento bem sucedido. A administração adequada de fluidos, a analgesia, a oxigenioterapia, a fisioterapia respiratória ativa e o uso criterioso de transfusões sanguíneas são elementos essenciais do tratamento. A hipertensão pulmonar (HP), por sua vez, tem sido recentemente reconhecida como uma das complicações mais graves e freqüentes destes pacientes. A pressão de artéria pulmonar deve ser medida periodicamente por meio de ecocardiografia. Se o diagnóstico de HP for confirmado, o uso de hidroxiuréia, anticoagulação, transfusões e oxigênio deveriam ser considerados. As manifestações cardíacas nas DF incluem cardiomegalia, isquemia miocárdica, disfunção ventricular e cor pulmonale. O tratamento destas complicações deve seguir as recomendações das diretrizes atuais.

The lung is a major target organ for acute and chronic complications in sickle cell disease. Acute chest syndrome is the second most common cause of hospital admission resulting in considerable morbidity and mortality. The mainstay of successful treatment remains high quality supportive care. Fluid management, analgesia, oxygenation, bronchodilators, incentive spirometry and judicious use of transfusion therapy are essential elements of supportive care management. Pulmonary hypertension (PHT) has emerged as one of the most frequent and serious complications in these patients. The pulmonary artery pressure should be evaluated periodically by echocardiography. If the PHT diagnosis is positive the use of hydroxiurea, anticoagulation, transfusions and oxygen therapy should be considered. Cardiac manifestations are common including enlargement of the heart, myocardial ischaemia, ventricular dysfunction and cor pulmonale. The management of these complications follows the current guidelines.

First case of immune-mediated haemolytic anaemia associated to imatinib mesylate.

Imatinib mesylate is a specific inhibitor of protein tyrosine kinase activity secondary to bcr-abl, mostly indicated for the treatment of patients with Philadelphia chromosome positive chronic myeloid leukaemia (CML). Generally, the undesirable effects of imatinib administration observed in clinical trials were of mild-to-moderate degree, and no haemolysis has been associated with this drug. We report here a case of immune-mediated haemolytic anaemia associated to imatinib mesylate successfully treated with prednisone in a patient with CML. Laboratory investigation showed anaemia [haemoglobin (Hb) of 59 g/L], reticulocyte of 61 x 10(9)/L and a positive direct antiglobulin test. Anti-drug in vitro studies revealed a positive result with gel microcolumn assay by an adsorption mechanism. Seventy-four days after prednisone therapy, the patient's Hb level was of 110 g/L with negative direct antiglobulin test and drug in vitro studies. This case demonstrated that patients treated with imatinib mesylate can present immune-mediated haemolysis and adequate management of this event can be done maintaining the drug and associating corticosteroids.