TY - JOUR
T1 - Dried Blood Spots for Measuring Vibrio cholerae-specific Immune Responses
AU - Iyer, Anita S.
AU - Azman, Andrew S.
AU - Bouhenia, Malika
AU - Deng, Lul O.
AU - Anderson, Cole P.
AU - Graves, Michael
AU - Kováč, Pavol
AU - Xu, Peng
AU - Ryan, Edward T.
AU - Harris, Jason B.
AU - Sack, David A.
AU - Luquero, Francisco J.
AU - Leung, Daniel T.
N1 - Funding Information:
This work was supported by The National Institute of Health (K08 AI100923 to D.T.L., R01 AI130378 to D.T.L., AI106878 to E.T.R., AI099243 and AI103055 to J.B.H.), The Bill and Melinda Gates Foundation (OPP1089243 to J.L., A.S.A., Delivering Oral Vaccine Effectively (DOVE) Project, OPP153556 to D.A.S., F.J.L., A.S.A., and OPP 1089248 to WHO), the Intramural Research Program of the National Institutes of Health, NIDDK (P.K., P.X.), and Margaret A Cargill Foundation grants to the WHO. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors would like to thank the study staff, participants, community leaders in the UN House PoC, staff at the WHO Juba Country Office, IMC Staff (Dr Meroni Abraham, Alejandro Guzman, Kourtney Rusow, Emebet Dlasso), MSF-Switzerland for help with logistics, and Mark Pankow, Ned Bedrio at Advance Dx, Inc. for gift of AdvanceDx100 cards.
Publisher Copyright:
© 2018 Iyer et al.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Background: Vibrio cholerae causes over 2 million cases of cholera and 90,000 deaths each year. Serosurveillance can be a useful tool for estimating the intensity of cholera transmission and prioritizing populations for cholera control interventions. Current methods involving venous blood draws and downstream specimen storage and transport methods pose logistical challenges in most settings where cholera strikes. To overcome these challenges, we developed methods for determining cholera-specific immune responses from dried blood spots (DBS). Methodology/principal findings: As conventional vibriocidal assay methods were unsuitable for DBS eluates from filter paper, we adopted a drop-plate culture method. We show that DBS collected from volunteers in South Sudan, and stored for prolonged periods in field conditions, retained functional vibriocidal antibodies, the titers of which correlated with paired serum titers determined by conventional spectrophotometric methods (r = 0.94, p = 0.00012). We also showed that eluates from DBS Serum Separator cards could be used with conventional spectrophotometric vibriocidal methods, and that they correlated with paired serum at a wide range of titers (r = 0.96, p<0.0001). Similarly, we used ELISA methods to show that V. cholerae O-specific polysaccharide antibody responses from DBS eluates correlated with results from paired serum for IgG (r = 0.85, p = 0.00006), IgM (r = 0.79, p = 0.00049) and IgA (r = 0.73, p = 0.0019), highlighting its potential for use in determination of isotype-specific responses. Storage of DBS cards at a range of temperatures did not change antibody responses. Conclusion: In conclusion, we have developed and demonstrated a proof-of-concept for assays utilizing DBS for assessing cholera-specific immune responses.
AB - Background: Vibrio cholerae causes over 2 million cases of cholera and 90,000 deaths each year. Serosurveillance can be a useful tool for estimating the intensity of cholera transmission and prioritizing populations for cholera control interventions. Current methods involving venous blood draws and downstream specimen storage and transport methods pose logistical challenges in most settings where cholera strikes. To overcome these challenges, we developed methods for determining cholera-specific immune responses from dried blood spots (DBS). Methodology/principal findings: As conventional vibriocidal assay methods were unsuitable for DBS eluates from filter paper, we adopted a drop-plate culture method. We show that DBS collected from volunteers in South Sudan, and stored for prolonged periods in field conditions, retained functional vibriocidal antibodies, the titers of which correlated with paired serum titers determined by conventional spectrophotometric methods (r = 0.94, p = 0.00012). We also showed that eluates from DBS Serum Separator cards could be used with conventional spectrophotometric vibriocidal methods, and that they correlated with paired serum at a wide range of titers (r = 0.96, p<0.0001). Similarly, we used ELISA methods to show that V. cholerae O-specific polysaccharide antibody responses from DBS eluates correlated with results from paired serum for IgG (r = 0.85, p = 0.00006), IgM (r = 0.79, p = 0.00049) and IgA (r = 0.73, p = 0.0019), highlighting its potential for use in determination of isotype-specific responses. Storage of DBS cards at a range of temperatures did not change antibody responses. Conclusion: In conclusion, we have developed and demonstrated a proof-of-concept for assays utilizing DBS for assessing cholera-specific immune responses.
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U2 - 10.1371/journal.pntd.0006196
DO - 10.1371/journal.pntd.0006196
M3 - Article
C2 - 29377882
AN - SCOPUS:85041717491
SN - 1935-2727
VL - 12
JO - PLoS neglected tropical diseases
JF - PLoS neglected tropical diseases
IS - 1
M1 - e0006196
ER -