Kidney Week

Abstract: SA-PO417

The Association Between Lymphocyte Counts and Risk of Relapse and Risk of Serious Infection in Patients with ANCA-Associated Vasculitis

Session Information

• Glomerular Diseases: Clinical, Outcomes, Trials - III
  October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

• Pyne, Lonnie, McMaster University, Hamilton, Ontario, Canada

Lonnie Pyne,

• Walsh, Michael, McMaster University, Hamilton, Ontario, Canada

Michael Walsh,

• Quinn, Kathleen, Western University, London, Ontario, Canada

Kathleen Quinn,

• Khalidi, Nader A., McMaster University, Hamilton, Ontario, Canada

Nader A. Khalidi,

• Alharbi, Laila, macmaster university, Hamilton, Ontario, Canada

Laila Alharbi,

Background

Patients with anti-neutrophil cytoplasm antibody (ANCA) associated vasculitis (AAV) commonly have relapses of their disease and/or infections. Lymphocyte counts may represent both a biomarker of adequate immunosuppressive treatment and an increased risk of infection. We assessed the association between lymphocytes counts and both infection and relapse in patients with AAV.

Methods

We conducted a single centre, retrospective review of patients with known AAV and abstracted patient characteristics at the time of relapse requiring immunosuppressive treatment up to 24 months after relapse. We assessed the relationship between lymphocyte counts and the outcomes of relapse and infection using multi-level logistic regression in which laboratory data including lymphocyte counts were treated as time-varying. All models were adjusted for age, neutropenia, need for dialysis and type of ANCA.

Results

We identified 158 patients of which 149 had useable data. During the follow-up period there were 87 relapses in 59 patients and 39 infections requiring antibiotics in 26 patients. Lymphocyte counts <0.05 x 10⁹ were not significantly associated with relapse (odds ratio 1.02, 95% confidence interval 0.26 to 3.98). Lymphocyte counts <0.5 x 10⁹ were independently associated with infection (odds ratio 7.00, 95% confidence interval 2.77 to 17.7).

Conclusion

Lymphopenia appeared more strongly associated with infection than it was protective of relapse. These data suggest inducing lymphopenia may cause more harm than benefit in patients with AAV.