Urinary T Lymphocytes Predict Renal Flares in Patients With Inactive ANCA-associated Glomerulonephritis
Urinary T Lymphocytes Predict Renal Flares in Patients With Inactive ANCA-associated Glomerulonephritis
Urinary CD4+ and CD8+ T lymphocytes may predict renal flares in patients with inactive
 ANCA-associated vasculitis and thus serve as early non-invasive biomarkers. Urine samples of
 patients with inactive renal ANCA-vasculitis will be analysed by flow cytometry and compared
 to clinical outcome after 6 months.
Data of previous studies have shown that counts of urinary T lymphocyte subsets correlate
 with disease activity in several immunological renal diseases, e.g. ANCA-associated
 glomerulonephritis. Thus, study authors hypothesise that CD4+, respectively CD8+, T effector
 memory lymphocytes found in urine samples of patients with inactive ANCA-vasculitis predict
 subsequent renal flares. Therefore, quantification of these cellular subsets might reliably
 predict relapse of ANCA associated glomerulonephritis at an early stage. In a prospective
 experimental study urine of patients with ANCA-vasculitis and no renal involvement or
 patients in renal remission will be analysed by flow cytometry. After 6 months of
 observation, clinical outcome and potential renal relapse will be determined and correlated
 to initial T lymphocyte count.
Inclusion Criteria:

 -  diagnosed ANCA-associated vasculitis (clinical diagnosis of granulomatosis with
 polyangiitis, eosinophilic granulomatosis with polyangiitis or microscopic
 polyangiitis consistent with the Chapel-Hill consensus definitions AND positive test
 for proteinase 3-ANCA or myeloperoxidase-ANCA)

 -  no currently active renal involvement (defined as BVAS = 0 with exception of hematuria
 or proteinuria as signs of renal scars)

 -  written and informed consent

 Exclusion Criteria:

 -  urinary tract infection

 -  active menstrual bleeding

 -  current therapy with rituximab

 -  active renal involvement

 -  other active renal disease (e.g. diabetic nephropathy)