A case of adult-onset Still’s disease complicated by thrombotic thrombocytopenic purpura with retinal microangiopathy and rapidly fatal cerebral edema

We present a patient who had adult-onset Still’s disease (AOSD) complicated by thrombotic thrombocytopenic purpura (TTP) that resulted in retinal microangiopathy and rapidly fatal cerebral edema. The patient was a 37-year-old male who developed fever, eruption, arthritis and hepatic dysfunction, that, based on close examination, was diagnosed as AOSD. Despite treatment with corticosteroids, the patient developed acute visual field defect, neurological deterioration including convulsions and impaired consciousness, as well as acute renal failure that ultimately resulted in death. Pathological examination of autopsy specimens revealed multiple fibrin thrombi disseminated in small vessels of the brain and kidney, which was consistent with TTP, along with marked cerebral edema. Although TTP has rarely been reported in association with AOSD, awareness of the possible coexistence of these two diseases is important for diagnosis and treatment.     

Classification of radiation effects for dose limitation purposes: history,current situation and future prospects

Radiation exposure causes cancer and non-cancer health effects, each of which differs greatly in the shape of the dose–response curve, latency, persistency, recurrence, curability, fatality and impact on quality of life. In recent decades, for dose limitation purposes, the International Commission on Radiological Protection has divided such diverse effects into tissue reactions (formerly termed non-stochastic and deterministic effects) and stochastic effects. On the one hand, effective dose limits aim to reduce the risks of stochastic effects (cancer/heritable effects) and are based on the detriment-adjusted nominal risk coefficients, assuming a linear-non-threshold dose response and a dose and dose rate effectiveness factor of 2. On the other hand, equivalent dose limits aim to avoid tissue reactions (vision-impairing cataracts and cosmetically unacceptable non-cancer skin changes) and are based on a threshold dose. However, the boundary between these two categories is becoming vague. Thus, we review the changes in radiation effect classification, dose limitation concepts, and the definition of detriment and threshold. Then, the current situation is overviewed focusing on (i) stochastic effects with a threshold, (ii) tissue reactions without a threshold, (iii) target organs/tissues for circulatory disease, (iv) dose levels for limitation of cancer risks vs prevention of non-life-threatening tissue reactions vs prevention of life-threatening tissue reactions, (v) mortality or incidence of thyroid cancer, and (vi) the detriment for tissue reactions. For future discussion, one approach is suggested that classifies radiation effects according to whether effects are life threatening, and radiobiological research needs are also briefly discussed.