PMID- 15146423
OWN - NLM
STAT- MEDLINE
DCOM- 20040615
LR  - 20041117
IS  - 0004-3591 (Print)
IS  - 0004-3591 (Linking)
VI  - 50
IP  - 5
DP  - 2004 May
TI  - Antibodies to guanosine triphosphate misidentified as anti-double-stranded DNA 
      antibodies in a patient with antinuclear antibody-negative lupus, due to buckling 
      of insolubilized assay DNA.
PG  - 1533-8
AB  - OBJECTIVE: To investigate why the serum of a pediatric patient with systemic 
      lupus erythematosus was persistently (>30 months) and strongly positive for 
      antibodies to double-stranded DNA (dsDNA) as revealed by enzyme-linked 
      immunosorbent assay (ELISA), but yielded negative results on the antinuclear 
      antibody test (HEp-2 immunofluorescence [IF]). METHODS: The patient's antibodies 
      were isolated on dsDNA and single-stranded DNA (ssDNA) supports, which were then 
      examined by dsDNA ELISA and HEp-2 IF. Tests included the use of various 
      inhibitors to determine the fine specificity of the antibodies. Other tests 
      performed included immunoblotting, immunoprecipitation, Crithidia luciliae IF, 
      and neutrophil IF. RESULTS: The antibodies isolated from the dsDNA and ssDNA 
      supports were similar, in that they were of the IgG type, bound well in the dsDNA 
      ELISA, and recognized a normally hidden nucleolar RNA antigen in HEp-2 cells. 
      With both the dsDNA ELISA and nucleolar antigens, inhibition studies revealed 
      that the epitope recognized was guanosine 5'-triphosphate (GTP). Binding of the 
      antibodies was better to GTP than to guanosine 5'-monophosphate or cytidylyl 
      (3'-5') guanosine, and, in turn, was better than to guanosine, while 
      N7-methylated GTP was unreactive. The antibodies did not bind to dsDNA present in 
      solution or in HEp-2 or Crithidia cells, but bound transfer RNA well and 
      recognized a cytoplasmic RNA antigen in neutrophils. CONCLUSION: A new problem in 
      dsDNA ELISA is revealed in the occurrence of a hitherto-unknown and unusual 
      buckling of the insolubilized DNA molecule, which, absent in dsDNA found in 
      solution or in whole cells, presumably creates gaps of single-strandedness in the 
      molecule. A new antibody specific for GTP is described in this patient, which may 
      be clinically important.
FAU - Ma, Chun Hung
AU  - Ma CH
AD  - Clinical Immunology Unit, Prince of Wales Hospital, The Chinese University of 
      Hong Kong, Shatin, Hong Kong.
FAU - Hui, Joannie
AU  - Hui J
FAU - Tang, Janet Tsui Ying
AU  - Tang JT
FAU - Leung, Danny Tze Ming
AU  - Leung DT
FAU - Chui, Yiu Loon
AU  - Chui YL
FAU - Fok, Tai Fai
AU  - Fok TF
FAU - Lim, Pak-Leong
AU  - Lim PL
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Arthritis Rheum
JT  - Arthritis and rheumatism
JID - 0370605
RN  - 0 (Antibodies, Antinuclear)
RN  - 86-01-1 (Guanosine Triphosphate)
RN  - 9007-49-2 (DNA)
SB  - IM
MH  - Antibodies, Antinuclear/*blood
MH  - Antibody Specificity
MH  - Child
MH  - DNA/*immunology/metabolism
MH  - Enzyme-Linked Immunosorbent Assay/*standards
MH  - False Positive Reactions
MH  - Female
MH  - Guanosine Triphosphate/*immunology
MH  - Humans
MH  - Lupus Erythematosus, Systemic/diagnosis/*immunology
MH  - Solubility
EDAT- 2004/05/18 05:00
MHDA- 2004/06/16 05:00
CRDT- 2004/05/18 05:00
PHST- 2004/05/18 05:00 [pubmed]
PHST- 2004/06/16 05:00 [medline]
PHST- 2004/05/18 05:00 [entrez]
AID - 10.1002/art.20188 [doi]
PST - ppublish
SO  - Arthritis Rheum. 2004 May;50(5):1533-8. doi: 10.1002/art.20188.