Rheumatoid arthritis: review of searches for an infectious cause. Part II

Cost of illness and quality of life of patients with rheumatoid arthritis in South Korea

OBJECTIVE

To estimate the cost of illness (COI) and health-related quality of life (HRQOL) of rheumatoid arthritis (RA) according to four different levels of functional severity.

METHODS

A face-to-face interview survey was administered to patients with RA recruited at the Rheumatology Clinic of Seoul National University Hospital. Direct costs (medical costs [treatment, drug, private physiotherapy, traditional Chinese medicine, other alternative medicine], nonmedical costs [travel, dietary supplements, auxiliary device, home assistance]), indirect costs (productivity loss due to job loss and sick leave), and deterioration in the HRQOL of patients with RA were measured. Factors associated with the COI and the HRQOL were analyzed by using multiple regression and multivariate logistic regression.

RESULTS

A total of 196 patients were enrolled for this study. As RA functional severity worsened, the total costs increased accordingly (class I: 4,230,204 Korean won, class II: 7,250,674 Korean won, class III: 8,046,434 Korean won, class IV: 8,206,215 Korean won). Direct costs also increased with the severity of the functional status, with a sharp decrease in class IV. The average HRQOL score was 0.49, showing an evident impact of RA severity (class I: 0.67, class II: 0.50, class III: 0.29, class IV: 0.23). Functional class and comorbidity were significant determinants of the COI and the HRQOL.

CONCLUSION

Functional severity was a major factor associated with higher COI and lower HRQOL scores. Therefore, preventing the aggravation of functional severity is crucial for decreasing the COI and improving the HRQOL of patients with RA.

An uncooked vegan diet shifts the profile of human fecal microflora: computerized analysis of direct stool sample gas-liquid chromatography profiles of bacterial cellular fatty acids

The effect of an uncooked extreme vegan diet on fecal microflora was studied by direct stool sample gas-liquid chromatography (GLC) of bacterial cellular fatty acids and by quantitative bacterial culture by using classical microbiological techniques of isolation, identification, and enumeration of different bacterial species. Eighteen volunteers were divided randomly into two groups. The test group received an uncooked vegan diet for 1 month and a conventional diet of mixed Western type for the other month of the study. The control group consumed a conventional diet throughout the study period. Stool samples were collected. Bacterial cellular fatty acids were extracted directly from the stool samples and measured by GLC. Computerized analysis of the resulting fatty acid profiles was performed. Such a profile represents all bacterial cellular fatty acids in a sample and thus reflects its microflora and can be used to detect changes, differences, or similarities of bacterial flora between individual samples or sample groups. GLC profiles changed significantly in the test group after the induction and discontinuation of the vegan diet but not in the control group at any time, whereas quantitative bacterial culture did not detect any significant change in fecal bacteriology in either of the groups. The results suggest that an uncooked extreme vegan diet alters the fecal bacterial flora significantly when it is measured by direct stool sample GLC of bacterial fatty acids.

Borderline-tissues as sites of antigen deposition and persistence--a unifying concept of rheumatoid inflammation?

In organs of rheumatoid inflammation avascular tissue is nourished by perfusion either directly from the blood stream or by neighbouring blood vessels (borderline-tissue). An open question remains whether this borderline-tissue promotes only the known antigen persistence, or also the first deposition of the pathogenetically important microbial antigen, and subsequently a deposition of immune complexes. The three markers (carbon, latex, and living bacteria) used in this study led to nearly the same pattern of deposition in two groups of organ systems: Organs with clearance function belonging to the mononuclear phagocyte system (MPS); organs with borderline-tissues: joint, kidney, artery, heart valve, and eye. This deposition at the borderline can be observed best in areas of the joint where highly vascularized tissues are adjacent to avascular tissues nourished via perfusion: perichondrium, peritendineum, periosteum, and endo- and perimysium. These localisations of particle deposition correspond exactly with the intraarticular predilection sites of chronic rheumatoid inflammation in man and animals. Our results indicate an easier settlement of corpuscular material in these localisations, which at the same time are unable to eliminate such substances, unlike the organs of the MPS. Our studies seem to support the theory of pathogenetic importance of the borderline-tissues as a localizing factor in the perpetuating rheumatoid inflammation.

Association of parvoviruses with rheumatoid arthritis of humans

A small virus resembling parvoviruses in its morphological and physicochemical properties was derived from synovial tissue of a patient with severe rheumatoid arthritis. This virus, designated RA-1, elicits a syndrome in neonatal mice that includes neurological disturbances, permanent crippling of limbs, dwarfism, alopecia, blepharitis, "masking," and a rigid curvature of the thoracic spine. Polyclonal antibodies against RA-1 display high virus neutralizing activity and in immunoassays detect reactive antigen in synovial cells from different rheumatoid arthritis patients but not persons with osteoarthritis. Putative parvoviruses isolated from several other rheumatoid arthritis patients are only weakly pathogenic for newborn mice but can generate RA-1 virus-specific antigens in tissues of these animals. It has not been established that RA-1 and existing parvoviruses of mammalian species are related.