Avaliação da estabilidade de anticorpos anti-eritrocitários irregulares em amostras biológicas para produção de controles internos em laboratórios de imuno-hematologia

Abstract

Adipose tissue can impact differently depending on its localization and amount of stored fat. Marrow adipose tissue (MAT) expansion occurs in catabolic conditions associated with bone loss, such as anorexia nervosa and glucocorticoid therapy. Conversely, obesity is related to high or normal BMD and no change in MAT. Our aim was to evaluate the relationship of lipids depots with bone mass and MAT in conventionally treated T1D and T1D subjects submitted to hematopoietic stem cell transplantation (HSCT). The study comprised 3 groups matched by age, gender, height and weight: Control (13M/11F; 29±6 years; 67.4±14.4 Kg; 1.68±0.08 m; 23.8±3.7 Kg/m 2), T1D (13M/10F; 32±13 years; 72.3±10.6 Kg; 1.69±0.08 m; 25.3±3.4 Kg/m 2 ,17±11 years of diabetes duration) e T1D-HSCT (5M/4F; 25±6 years; 66.9±11 Kg; 1.72±0.11 m; 22.5±2.2 Kg/m 2 ; 6 months to 10 years after HSCT). Blood samples were collected to evaluate glycemic control. BMD were assessed by DXA. 1-H magnetic resonance spectroscopy (1,5T) was used to evaluate MAT [fat/(fat+water) %] in L3 vertebrae. Subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and intrahepatic lipids (IHL) were also evaluated by MRI. Only T1D exhibited poor metabolic control (HbA1c: Control=5.3±0.3%; T1D=9.6±2.2%; T1D-HSCT=6.4±0.5%; p<0.0001). Most T1D patients were overweighed (57%). BMD was similar between groups (e.g. L1-L4: Control=0.995±0.138 g/cm 2 ; T1D=0.977±0.132 g/cm 2 ; T1D-HSCT=0.971±0.115 g/cm 2 ; p>0.05). Low bone mass (Z-score>-2,0 or T-score>-1,0) prevalence among individuals was 12,5% (n=3) in the Control group, 26% (n=6) in the T1D conventionally treated group and 11% (n=1) in the T1D-HSCT group. SAT was higher in T1D whereas there was no difference in VAT, IHL and MAT (Control: 34.4±11.7 %; T1D: 34.2±8.5%; T1D-HSCT: 40.3±8.5%; p>0.05). Also, there no difference in MAT lipid composition between groups (p>0.05). SAT had a positive association with femoral neck BMD (for each unity of SAT = 0.0000055 g/cm 2 of BMD; p=0.02). Also, IHL had an inverse relationship with total hip and lumbar spine BMD (for each unity of IHL =-0.012 g/cm 2 of BMD; p=0.03). Other factors such as age and glycemic control also had a negative impact on bone mass. There was a positive correlation between VAT and IHL (r=0.40) whereas no association between IHL and MAT was found. Cholesterol (for each unity of cholesterol = 0.09% of MAT; p=0.0006) was an important preditor of MAT in L3. Yet, age (for each unity of age = 0.252% of MAT; p=0.0006) had a significant association with saturated fraction of MAT and male gender (-1.379% of MAT, p<0.0001) was a negative factor for the unsaturated fraction of MAT. Moreover, MAT did not have any association with lumbar spine BMD. Therefore, T1D bone mass was preserved and there were no changes in MAT content, independently of clinical treatment. This could be related to the nutritional status of T1D subjects. SAT accumulation was higher in T1D conventionally treated subjects compared to T1D-HSCT individuals probably due to more intense peripheral hyperinsuline...