Table of Contents

Component Description

IgG autoantibody testing of a subsample of stored serum from phase 1 (1988-91) NHANES III participants was conducted to estimate the prevalence and specificities of selected autoantibodies in the US population.

Eligible Sample

Participants aged 12 years and older from NHANES III (phase 1, 1988-1991) who were examined, had available surplus sera, and with specific laboratory findings based on prior testing (tested positive for HEp-2 indirect immunofluorescence assay (IFA) with dense fine speckled pattern (AC-2)) were eligible for inclusion (see: https://wwwn.cdc.gov/nchs/data/nhanes3/45a/SSNH3ANA.htm).

Description of Laboratory Methodology

Anti-DFS70 autoantibody determination using enzyme-linked immunosorbent assay (ELISA)
testing of IgG autoantibodies to human DFS70 antigen was performed by a DFS70 ELISA kit from Medical & Biological Laboratories Co., LTD (7808, Japan) as per manufacturer’s instructions. 

Laboratory Quality Assurance and Monitoring

ELISA analysis
Serum samples previously tested positive in HEp-2 indirect immunofluorescence assay (IFA) with nuclear dense fine speckled pattern (AC-2) were selected for anti-DFS70 autoantibody ELISA analyses. Established protocols were completed as outlined by the manufacturer with a positive-negative cutoff as recommended at 15 unit/mL. (i.e. 15 or under = negative).

Samples were analyzed in duplicates and values represent averaged data. Samples that showed discrepant results were repeated. Repeats were performed whenever there was any doubt for accuracy or technical issues.

Data Processing and Editing

Data Access: All data are publicly available.

Analytic Notes

Weighting:

Special subsample weights, WTANA1, are required to analyze the ANA data and they are provided in the data sets. This file is intended to be used in conjunction with the SSNH3ANA file. Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 12 YEARS - 150 YEARS

WTANA1 - Phase 1 SSANA subsample weights

Variable Name:
WTANA1
SAS Label:
Phase 1 SSANA subsample weights
English Text:
Phase 1 SSANA subsample weights
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1218.849016 to 319282.73119 Range of Values 154 154
. Missing 0 154

SSDFSS - Dense fine speckled signal

Variable Name:
SSDFSS
SAS Label:
Dense fine speckled signal
English Text:
Dense fine speckled signal
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 to 4 Range of Values 154 154
. Missing 0 154

SSDFSE - Dense fine speckled EIS unit

Variable Name:
SSDFSE
SAS Label:
Dense fine speckled EIS unit
English Text:
Dense fine speckled EIS unit
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.13 to 145.71 Range of Values 154 154
. Missing 0 154

SSDFSR - Dense fine speckled result

Variable Name:
SSDFSR
SAS Label:
Dense fine speckled result
English Text:
Dense fine speckled result
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Negative 77 77
1 Postive 77 154
. Missing 0 154