Purpose: Immunological, neuroendocrine; To investigate changes in cell-mediated immune function after the administration of 2 closely-spaced doses of MDMA in a attempt to imitate conditions experienced by some ecstasy users.

Design: Study 1: Randomized placebo-controlled within-subjects design (incompletely crossed), with drug 1 (placebo or 100 mg MDMA) serving as one within-subjects factor and drug 2 (100 mg MDMA or placebo) given 4 h later as second within-subjects factor. All participants received all 3 treatments, placebo-placebo, MDMA-placebo and MDMA-MDMA. Immunological function, plasma cortisol and plasma MDMA was measured in all participants.

Subjects: 8 MDMA-experienced males. Age and recruitment method not reported. May have been recruited through "word of mouth" as were participants in Mas et al, 1999.

Criteria for Inclusion - No information provided concerning inclusion or exclusion criteria. However, past papers published by this team have included individuals who were healthy, as determined via physical and psychiatric examination, with no current drug or alcohol dependence save for nicotine. All participants had to be male and had to have used ecstasy on at least 5 occasions without adverse reactions to the drug. In previous reports, these researchers have also verified that participants in their MDMA studies have extensive cytochrome P450 isozyme 2D6 activity. Although it was not stated in this publication, the same criterion was probably used here.

Measures: Immunological Function - Complete blood profile and cell count conducted on blood drawn from each subject, with samples drawn at baseline and at 1.5, 4, 5.5, and 24 h post drug 1. Subjects' lymphocytes cultured in vitro, and lymphocyte proliferation in response to phytohaemoaglutinin A (PHA, a mitogen) measured via radioimmunoassay. Number of lymphocytes counted by cytometer. Dual-color immunophenotyping used to detect immune cell types; helper-inducer, cytotoxic-suppressor, natural killer, mature B and T lymphocytes).

Plasma MDMA - MDMA concentration measured with gas chromatography from samples drawn at baseline and 1, 2, 4, 5, 6, 10 and 24 h post-drug. Plasma Cortisol - Using same set of samples described above (Plasma MDMA), performed a fluorescence polarization immunoassay (FPIA), with assay sensitivity set at .45 Ug / dL.

Analyses: Values for lymphocyte subsets, plasma cortisol concentrations were transformed into differences from baseline, and maximum change from baseline was calculated for these variables. Stimulation index was calculated for lymphocyte response to mitogens. AUC was calculated for concentrations of CD4 cells, NK cells and MDMA via trapezoidal rule. A one-way (within-subjects) analysis of variance was performed on all data, with comparisons made across condition (placebo-placebo, MDMA-placebo or MDMA-MDMA). Significant differences were compared via Tukey's test, and p = 0.05.

Results: Immunological Function - First dose of MDMA produced decrease in CD4 cells and CD4/CD8 ratio in plasma, and lymphocytes were less responsive to PHA stimulation. NK cells increased after first dose of MDMA. All changes peaked at 1.5 h after administration. A second dose of MDMA given 4 h after Dose 1 produced the same decreases and increases (enhancing or in addition to the effects of dose 1). When compared with placebo, participants receiving a second dose of MDMA showed significantly greater immunological changes 24 h after treatment.

Plasma Cortisol - A single dose of MDMA produced an increase in plasma cortisol concentrations, with plasma cortisol peaking 2 h post-drug. A second dose of MDMA given 4 h after Dose 1 also increased plasma cortisol (which had begun decreasing after peak from Dose 1).

Plasma MDMA - Immunological changes followed course of plasma MDMA for dose 1. Second dose of MDMA produced higher plasma MDMA concentrations than did Dose 1.

Overall Effects: The immunological effects of MDMA in humans produced by a single dose of 100 mg MDMA were also produced by a second dose of MDMA given 4 h after the first dose. Changes peaked 1 to 2 h post-drug, and immunological changes produced by Dose 1 were enhanced by a second dose of MDMA 4 h after the first dose. Most changes were no longer present 24 h post -drug. As with the first dose, the second dose also produced decreased CD4 count, increased NK count and decreased lymphocyte proliferation in response to PHA. It appears that the second dose enhanced the immunological changes produced by the first dose.

Adverse Effects: None reported besides changes in cell mediated immune responses.

Comments: The paper reports the first findings in a controlled clinical trial involving the administration of more than one dose of MDMA per trial, with the second dose administered 4 hours after the first administration. While no adverse effects are reported in response to the second dose of MDMA, administering the second dose did exacerbate immunological dysfunction produced by the initial dose. It may not be appropriate to generalize from these study findings due to small sample size and because all participants were male. The study findings may have implications both for patterns of non-medical (illicit) use of ecstasy and for the use of "boosters" in MDMA-assisted psychotherapy.