The objective of this study was to pilot test a model to study local immunologic changes that occur during natural exacerbations of CRS.
Among 806 relapsing remitting onset patients (Lublin and Reingold, 1996) from the original population-based natural history cohort, exacerbations were defined as acute development of new symptoms or worsening of existing symptoms, lasting >24 h (Poser et al., 1983; Lublin and Reingold, 1996).
Bacterial infection goes through a natural course of acute exacerbation and recovery with antibiotics.
7 Previous research into the natural history of COPD exacerbations has mainly focused on prospective cohorts of patients who have usually been recruited from secondary and/or tertiary care.
This could be due to an exacerbation of the natural process of age-related lipofuscinosis leading to the much larger and denser deposits that we identify as autofluorescent aggregates.
Fortunately, the natural history of most COPD exacerbations is that the symptoms will resolve and the patient will return to their usual health status prior to the exacerbation [ 51].
Episodes of acute functional deterioration, known as exacerbations, punctuate the natural history of COPD and account for most of the morbidity, mortality, and health care costs associated with this condition (12).
Exacerbations are key events in the natural history of COPD and patients who exacerbate frequently form a discrete phenotype of patient [ 19].
The prospective population-based Rotterdam Study is ideally suited to investigate key research questions of Chronic Obstructive Pulmonary Disease COPDD) regarding its pathogenesis, epidemiology, environmental and genetic risk factors, natural history of the disease, phenotypes, exacerbations and co-morbidities [ 391].
Oumeish and Al-Fouzan recognized the potential role of sex hormones in the etiology of psoriasis, since pregnancy, a state of natural immunomodulation, is associated with alleviation or exacerbation in various inflammatory diseases, including psoriasis [ 45, 46].
