Sindrome de hipersensibilidade a dapsona: revisao sistematica dos criterios diagnosticos / Dapsone hypersensitivity syndrome: a systematic review of diagnostic criteria

A importancia mundial da farmacovigilancia vem aumentando, mesmo nos paises subdesenvolvidos. Neste contexto, a sindrome de hipersensibilidade a dapsona (SHD), um efeito colateral raro e potencialmente grave, deve ser considerada, sem, entretanto, comprometer a seguranca da droga e sua ampla utilizacao. Objetivando padronizar os criterios diagnosticos da sindrome, realizou-se uma revisao sistematica da literatura analisando trabalhos, publicados de quinze paises endemicos entre 1956 e 2001. Cento e oito casos foram reportados neste periodo, destes 96,2% apos 1980, com 13,3% de obitos. Neste grupo, 59% apresentaram a sindrome completa - febre, rash, linfadenopatia e hepatite, enquanto 41% expressaram forma incompleta. A taxa de mortalidade do grupo que preenche os criterios de SHD completa foi 9,6% e nao houve associacao estatistica com injuria hepatica. Todavia ressalta-se pouca qualidade dos dados coletados, o que reforca a necessidade de relatos mais precisos em futuras publicacoes.

Human venous and arterial glycosaminoglycans have similar affinity for plasma low-density lipoproteins.

We compared the glycosaminoglycan content of human venous and arterial walls. The most abundant glycosaminoglycan in human veins is dermatan sulfate whereas chondroitin 4/6-sulfate is preponderant in arteries. The concentrations of chondroitin 4/6-sulfate and heparan sulfate are approximately 4.8- and approximately 2.5-fold higher in arteries than in veins whereas dermatan sulfate contents are similar in the two types of blood vessels. Normal and varicose saphenous veins do not differ in their glycosaminoglycan contents. It is known that certain glycosaminoglycan species from the arterial wall, mainly high-molecular-weight fractions of dermatan sulfate+chondroitin 4/6-sulfate have greater affinity for plasma LDL. These types of glycosaminoglycans can be identified on a LDL-affinity column. We now demonstrated that a similar population of glycosaminoglycan also occurs in veins, although with a lower concentration than in the arteries due to less chondroitin 4/6-sulfate with affinity for LDL. The concentrations of dermatan sulfate species, which interact with LDL, are similar in arteries and veins. The presence of these glycosaminoglycans with affinity to plasma LDL in veins raises interesting questions concerning the role of these molecules in the pathogenesis of atherosclerosis. Possibly, the presence of these glycosaminoglycans in the vessel wall are not sufficient to cause retention of LDL and consequently endothelial dysfunction, but may require additional intrinsic factors and/or the hydrodynamic of the blood under the arterial pressure.