1998 Fiscal Year Final Research Report Summary
Elucidation of complement cold activation and cryoglobulin formation associated with HCV infection.
| Project/Area Number |
08672653
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Laboratory medicine
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| Research Institution | Osaka Medical College |
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Principal Investigator |
SHIMIZU Akira Osaka Medical College, Department of Clinical Pathology, Professor, 医学部, 教授 (00028581)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANISHI Toyofumi Osaka Medical College, Department of Clinical Pathology, Assistant Professor, 医学部, 講師 (10247843)
NAKAGAWA Toshimasa Osaka Medical College, Department of Clinical Pathology, Associate Professor, 医学部, 助教授 (30237226)
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| Project Period (FY) |
1996 – 1998
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| Keywords | complement CH50 / cold acfivation(CA) / HCV intection / rheumatoid factor / liver cirrhosis / non-Hodgkin's lymphoma / IL-2 receptor / cryoglobulin |
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| Research Abstract |
Since the mid 1970's the in vitro activation of the classical complement pathway at a low temperature has been accepted as cold activation (CA) of the complement (1). We have proved that this activation is strongly associated with HCV infection (2). The complement may be activated by an immune complex formed at a low temperature and this may be related to cryoglobulin. The incidence of positive cases for RF among patients with HCV antibody was higher than among cases without HCV antibody (3). In addition, the incidence of RF positivity among cases showing cold activation was higher than among those with no cold activation (3). Sera of HCV antibody positive and cold activation positive showed a high incidence of elevation of RF during storage at low temperature (4) but the elevation was suppressed by addition of guinea pig serum as a complement source or in a buffer with a higher ionic strength. In the presence of HCV infection, a subset (or subsets) of B-lymphocytes proliferates and a clone (or clones) of B-cells excreting a particular type of RF may expand.
It has been reported that the incidence of HCV infection is high in a group with non-Hodgkin's lymphoma (NHL) and serum levels of soluble interleukin-2 receptors (slL-2R) are increased in NHL patients and relate to the tumor burden. It has also been reported that HCV-related NHL complicating mixed cryoglobulinaemia represents a particular patient's subset in which particular genetic and / or environmental factors can also be involved. We measured slL-2R, and HCV in 44 NHL and 5 adult T cell leukemia patients. HCV antibody and/or HCV-RNA were positive in 330% cases. Surprisingly, the levels of slL-2R in HCV positive cases were significantly low when compared to those in HCV negative cases. HCV infection may cause expansion and neoplastic transformation of a particular clone of lymphocytes.
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