Risk of Guillain-Barré syndrome after meningococcal conjugate vaccination.

PURPOSE: A new meningococcal conjugate vaccine (MCV4) was introduced in 2005. Shortly after, case reports of Guillain-Barré syndrome (GBS), a serious demyelinating disease, began to be reported to the Vaccine Adverse Event Reporting System. In 2006, the Centers for Disease Control and Prevention and the Food and Drug Administration requested the evaluation of GBS risk after MCV4 vaccination. We conducted a study to assess the risk of GBS after MCV4 vaccination using health plan administrative and claims data together with the review of primary medical records of potential cases. METHODS: Retrospective cohort study among 12.6 million 11- to 21-year-old members of five US health plans with a total membership of 50 million. Automated enrollment and medical claims data from March 2005 through August 2008 were used to identify the population, the vaccinations administered, and the medical services associated with possible GBS. Medical records were reviewed and adjudicated by a neurologist panel to confirm cases of GBS. The study used distributed data analysis methods that minimized sharing of protected health information. RESULTS: We confirmed 99 GBS cases during 18,322,800 person-years (5.4/1,000,000 person-years). More than 1.4 million MCV4 vaccinations were observed. No confirmed cases of GBS occurred within 6 weeks after vaccination. The upper 95% CI for the attributable risk of GBS associated with MCV4 is estimated as 1.5 cases per 1,000,000 doses. CONCLUSIONS: Among members of five US health plans, MCV4 vaccination was not associated with increased GBS risk.

Posttransplant lymphoproliferative disorder among renal transplant patients in relation to the use of mycophenolate mofetil.

BACKGROUND: The introduction of increasingly effective immunosuppressants has raised the question of whether posttransplant lymphoproliferative disorder (PTLD), a complication of immunosuppression, would become more frequent. This study assessed the risk of PTLD in relation to immunosuppression during a period that saw the introduction and eventual market dominance of mycophenolate mofetil (MMF). METHODS: A case-control study was conducted at 23 U.S. transplant centers. All participants received a renal-only transplant on or after July 1, 1995. PTLD cases were reported by centers and confirmed by central review. The United Network for Organ Sharing (UNOS) supplemented case ascertainment and identified controls matched on center, transplant date, and age. Center personnel abstracted risk factor and therapy data for cases and up to four controls per case. Cases and controls were compared, using a matched multivariate analysis, to assess the impact of MMF as one component of triple-therapy adjusted for other drug therapies and known risk factors. RESULTS: Data were collected for 108 PTLD cases and 404 controls. PTLD risk for individuals on triple therapy with MMF was similar to the risk experienced by individuals on triple therapy with no MMF (adjusted odds ratio=1.19; 95% CI 0.55-2.55). There was no dose response relationship between MMF and PTLD risk. CONCLUSIONS: Use of MMF was not associated with an increase in PTLD among patients who received triple immunosuppressive therapy, but an excess in risk as large as 155% or a reduction in risk by as much as 45% cannot be ruled out.

Methods and objectives of a large US multicenter case-control study of post-transplant lymphoproliferative disorder in renal transplant patients.

A large multicenter case-control study is in progress in the United States, the primary goal of which is to provide information about the effects of specific immunosuppressants and other risk factors on posttransplant lymphoproliferative disorder (PTLD) in renal transplant patients. It will also provide incidence data and case characterization on PTLDs arising in a large contemporary population. Medical record data are being collected on up to 120 PTLD cases and up to four controls per case transplanted at 20 large US centers. Participants all received transplants on or after July 1, 1995 and PTLD cases will be identified through December 31, 2001. All cases undergo central clinical and pathologic review. Abstracted information includes detailed data (dosages, duration) on all immunosuppressants (induction, maintenance, anti-rejection) as well as antiviral treatment. Other data include demographics, transplant history, HLA matching and viral status (e.g., Epstein-Barr virus, cytomegalovirus). Information associated with the PTLD diagnosis and initial therapy for PTLD is also collected. To date, 86 potential cases have been reported. Twenty (24%) are pediatric patients (< or =18 years). Median time between transplant and PTLD is 268 days; 53 (62%) were diagnosed within the first year. Cumulative incidence through 1998 is 0.7% for adults and 4.5% for children. The most common single site for PTLD is the allograft. Common treatments included either a reduction or discontinuation of immunosuppression (90%) and antiviral treatment (66%). Overall, the allograft appears to be an important site of PTLD recurrence. Also, the incidence of renal PTLD since the introduction of new immunosuppressive therapies is similar to that reported earlier.

Randomized field trial of vaginal douching, pelvic inflammatory disease and pregnancy.

BACKGROUND: Several case-control studies have reported that women who use vaginal douche products are at increased risk for pelvic inflammatory disease. Women who douche regularly may do so for reasons related to their risk of acquiring a sexually transmitted infection, introducing confounding that is difficult to control in non-experimental studies. METHODS: We conducted a multicenter randomized field trial with a 1-year follow-up period. The study comprised 1827 women age 18-34, with no current indication of pelvic inflammatory disease, who were regular users of a douche product and who had been treated recently for a sexually transmitted bacterial infection or bacterial vaginosis. Women were randomly assigned to use either a newly designed and marketed douche product or a soft cloth towelette, and were resupplied with product at each bimonthly follow-up visit. We measured the occurrence of pelvic inflammatory disease using a combination of clinical and laboratory indicators. We also recorded pregnancy occurrence among participants. RESULTS: The risk of PID among women assigned to use the douche product, relative to that among women assigned to use the wipe product, was 1.05 (95% confidence interval = 0.57-1.9). Using an alternative, less sensitive definition of PID gave a risk ratio of 1.26 (0.62-2.6). The probability of becoming pregnant was 15% lower among women assigned to use a douche product, and 33% lower among women who douched more frequently (ratio = 0.67; 0.42-1.08). CONCLUSIONS: There was little or no indication of a greater risk of PID among women assigned to use the douche product. Douching may be related to a lower probability that a woman becomes pregnant.