HLA and age of onset in myasthenia gravis.

The aetiology of MG is unknown, but both genetic and environmental factors are important. Over the years association of MG with Human Leucocyte Antigens (HLA) has been described in different populations. We investigated a possible association between HLA-DRB1 alleles and age of onset in MG. One hundred and fourteen MG patients (82 females) and 282 control individuals (CP) were studied. Patients were classified according to the age of onset (early-onset <50, n = 74 and late-onset ≥ 50, n = 20). Patients with thymoma (n = 20) were analyzed separately. HLA-DRB1 and HLA-B*08 genotyping was performed using PCR-SSP methodology. HLA-DRB1*03 allele was overrepresented in the global MG. When the early-onset subgroup was considered, this association became even stronger. Regarding the late-onset subgroup, the frequency of HLA-DRB1*01 allele was higher than in the CP. For the thymoma subgroup, the HLA-DRB1*10 allele frequency was significantly higher when compared to the CP. These results have shown a strong association of HLA-DRB1*03 with MG, especially for EOMG also in our population. HLA-DRB1*01 was associated to LOMG suggesting that is a susceptibility factor for this subgroup of the disease. This study confirms a different genetic background of MG subgroups regarding age of onset.

Anticipation of presbyopia in Portuguese familial amyloidosis ATTR V30M.

The aim of this study was to evaluate if Portuguese patients with familial amyloidosis, liver transplanted and not, have an earlier development of presbyopia compared with a normal population and its relation with the presence or the absence of anterior capsule opacification of the lens. This study was performed to evaluate if Portuguese patients with familial amyloidosis and in a blood donors population (control group). Three hundred and fifty-six subjects, 144 amyloidotic patients and 212 healthy individuals, were evaluated for the need of plus lenses for normal near reading (Jaeger chart 1 at 33 cm). In familial amyloidosis patients, the value of the add-power was related to age, liver transplantation status, and presence of visible anterior capsule opacification of the lens. In both groups, the value of add-power was positively correlated with age (r=0.91; P<0.005). Familial amyloidosis patients require more add-power than control individuals of similar age, and need to use reading glasses at earlier ages. The age of onset of presbyopia in familial amyloidosis patients was significantly lower than in control individuals (32 years vs. 42 years). Adjusting for age, no significant difference was observed in add-power values between liver transplanted and not transplanted amyloidotic patients, suggesting that liver transplantation has no influence on presbyopia evolution in these patients. Familial amyloidosis patients had an earlier onset of presbyopia, probably related to amyloid deposition on the anterior capsule of the lens, which is not halted by liver transplantation.