title: Relationship of leukocyte CR1 transcript and protein with the pathophysiology and prognosis of systemic lupus erythematosus: a follow-up study.
abstract: Complement Receptor 1 (CR1) is a key complement regulatory protein (CRP) involved in the clearance of immune complexes. Earlier, we reported a marked decline of leukocyte CR1 (L-CR1) transcript and protein in patients with active systemic lupus erythematosus (SLE) and suggested L-CR1 transcript as a putative non-invasive disease marker for SLE. This follow-up study involving 18 patients with active SLE was conducted for further confirmation of the relationship between L-CR1 and SLE. Blood samples from the patients were collected on day 1 of the diagnosis (0 month) and at different time intervals (3 and 6 months) for analysis of L-CR1 transcript and L-CR1 protein by semi-quantitative reverse-transcriptase-polymerase chain reaction (RT-PCR) and western blotting respectively. Within 6 months, 15 patients entered remission. On day 1, the mean values of L-CR1 transcript (8.42 ± 3.53) and L-CR1 protein (4683 ± 1094) in the SLE patients were 6 times and 12 times lower than the normal controls (n = 103). At the end of month 6, these values increased by 4.5 and 6.5 times respectively for CR1 transcript (37.86 ± 8.52) and protein (30,265 ± 8614). Simultaneously, the SLE Disease Activity Index (SLEDAI) scores decreased by 4.8 times (4.47 ± 3.32) as compared with the scores obtained on day 1 (21.45 ± 5.67). Moreover, CR1 values correlated negatively with the SLEDAI scores. Levels of L-CR1 protein and transcript remained low in the three patients who did not enter remission. All of the above results suggested that an increase in the levels of L-CR1 related to good prognosis. Since the levels of L-CR1 protein is influenced by variables like proteolytic cleavage and secretion from leukocytes, the values of L-CR1 transcript on day 1 and subsequent follow-up points may bring a better insight into the state of the disease activity. An extended follow-up study is needed to confirm the significance of L-CR1 as a prognostic marker for SLE.
authors.affiliation: Department of Medicine, University of Pennsylvania, Philadelphia, USA.
authors.forename: V
authors.initials: V
authors.lastname: Arora
authors.forename: R
authors.initials: R
authors.lastname: Grover
authors.forename: A
authors.initials: A
authors.lastname: Kumar
authors.forename: D
authors.initials: D
authors.lastname: Anand
authors.forename: N
authors.initials: N
authors.lastname: Das
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D011379:Prognosis; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics; D017463:Receptors, Complement 3b / Q000097:blood* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D015415:Biomarkers; C509991:CR1 protein, human; D012333:RNA, Messenger; D017463:Receptors, Complement 3b