Spontaneous Development of IgM Anti‐Cocaine Antibodies in Habitual Cocaine Users: Effect on IgG Antibody Responses to a Cocaine Cholera Toxin B Conjugate Vaccine. (1st February 2013)

• Record Type: Journal Article
• Authors: Orson, Frank M.; Rossen, Roger D.; Shen, Xiaoyun; Lopez, Angel Y.; Wu, Yan; Kosten, Thomas R.
• Is Part Of: American journal on addictions. Volume 22:Number 2(2013:Mar./Apr.)
• Page Start: 169
• Page End: 174
• Publication Date: 2013-02-01
• Subjects: Substance abuse -- Periodicals; Substance abuse -- Treatment -- Periodicals; 616.86005
• DOI: 10.1111/j.1521-0391.2013.00314.x
• Languages: English
• ISSNs: 1055-0496

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="ajad314-sec-0001" sec-type="section"> <title>Background and Objectives</title> <p>In cocaine vaccine studies, only a minority of subjects made strong antibody responses. To investigate this issue, IgG and IgM antibody responses to cocaine and to cholera toxin B (CTB—the carrier protein used to enhance immune responses to cocaine) were measured in sera from the 55 actively vaccinated subjects in a Phase IIb randomized double‐blind placebo‐controlled trial (TA‐CD 109).</p> </sec> <sec id="ajad314-sec-0002" sec-type="section"> <title>Methods</title> <p>Isotype specific ELISAs were used to measure IgG and IgM anti‐cocaine and anti‐CTB antibody in serial samples collected prior to and at intervals after immunization. We assessed IgG anti‐cocaine responses of patients with pre‐vaccination IgM anti‐cocaine antibodies. Competitive inhibition ELISA was used to evaluate antibody specificity.</p> </sec> <sec id="ajad314-sec-0003" sec-type="section"> <title>Results and Conclusions</title> <p>Before immunization, 36/55 subjects had detectable IgM antibodies to cocaine, and 9 had IgM levels above the 95% confidence limit of 11 μg/ml. These nine had significantly reduced peak IgG anti‐cocaine responses at 16 weeks, and all were below the concentration (40 μg/ml) considered necessary to discourage recreational cocaine use. The IgG anti‐CTB responses of these same subjects were also reduced.</p> </sec> <sec id="ajad314-sec-0004" sec-type="section"> <title>Scientific Significance</title> <p>Subjects who develop an IgM antibody response to cocaine in the course of repeated recreational exposure to this drug are significantly less likely to produce high levels of IgG antibodies from the cocaine conjugate vaccine. The failure may be due to recreational cocaine exposure induction of a type 2 T‐cell independent immune response. Such individuals will require improved vaccines and are poor candidates for the currently available vaccine. (Am J Addict 2013;22:169‐174)</p> </sec> </abstract>