A study has found that the severity of anemia in patients with antineutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis is associated with increased renal dysfunction and shorter survival rates.
The study, “Anaemia is an essential complication of ANCA-associated renal vasculitis: a single center cohort study,” was published in the journal BMC Nephrology.
Anemia is a common complication of autoimmune diseases such as rheumatoid arthritis and ANCA-associated renal vasculitis. Generally, it is referred to as anemia of chronic disease (ACD). However, based on previous studies, the underlying mechanisms of anemia in patients with ANCA-associated renal vasculitis are believed to be different from those in patients with other autoimmune diseases.
Researchers at the University of Tsukuba, in Japan, set out to investigate anemia’s prevalence and pathogenesis in patients with ANCA-associated renal vasculitis. The study included 45 patients with ANCA-associated renal vasculitis who had been diagnosed and treated between 2003 and 2014 at the University of Tsukuba Hospital. Patients were followed up for a median of 42 months.
All patients had anemia at the time of diagnosis. Of these, 92% had renal anemia, 56% had ACD, and 20% had anemia due to hemorrhage. Patients were classified into two groups, one with low minimum hemoglobin (min Hb; <7.5) and the other with high minimum Hb (>7.5).
No significant differences were seen between the two groups in terms of iron-related and inflammation-related parameters such as serum ferritin and serum C-reactive protein, respectively. However, serum albumin, maximum serum creatinine, minimum estimated glomerular filtration rate (eGFR), and serum cystatin C were significantly different between the two groups.
Overall, the results indicate that renal dysfunction with ANCA-associated renal vasculitis is associated with a high prevalence and severity of renal anemia, and that renal interstitial damage is associated with the severity of anemia. Furthermore, the results are consistent with previous studies, which suggest that the severity of anemia is associated with a patient’s prognosis for survival.
One of the study’s main limitations is that it is retrospective and included only a small number of patients. Additionally, patients had both renal anemia and ACD, making it difficult to distinguish between the two.
“We demonstrated a high prevalence of anemia in a cohort of patients with ANCA-associated renal vasculitis. A possible reason for the high prevalence of anemia in these patients was the interaction between renal anemia and ACD. The severity of anemia was associated with the degree of renal dysfunction and life prognosis,” the team concluded.