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Abstract: SA-PO698

Gender, Ethnicity, and Outcome in Thrombotic Microangiopathy (TMA) on Renal Biopsy: A Retrospective Study Evaluating the Demographic and Etiologic Spectrum

Session Information

Category: Pathology and Lab Medicine

  • 1602 Pathology and Lab Medicine: Clinical


  • Lui, Shu, Emory University School of Medicine, Atlanta, Georgia, United States
  • Cobb, Jason, Emory University School of Medicine, Atlanta, Georgia, United States
  • Farris, Alton Brad, Emory University School of Medicine, Atlanta, Georgia, United States
  • Ellis, Carla L., Emory University School of Medicine, Atlanta, Georgia, United States

TMA is a systemic disease with diverse etiologies, characterized histologically by endothelial injury. Studies have reported an increased incidence and mortality rate in African American (AA) females with TMA. Our study seeks to determine if this finding is reproducible in a population of patients with evidence of TMA on renal biopsy.


A retrospective search of our pathology data system was conducted to identify all renal biopsies with a diagnosis of TMA from January of 2015 to May of 2018. Groups were analyzed in terms of gender, ethnicity, native versus allograft, presence of associated rejection and cause of ESRD in the allograft population. The presence of ESRD or a doubling of the serum creatinine from the time of the biopsy until the latest follow up date was defined as an unfavorable outcome.


Sixty-six cases were reviewed with the demographic data. Number of total and (allograft) biopsies is shown in the table. There was no statistically significant difference between the groups in terms of gender, ethnicity, unfavorable or favorable outcome, numbers of native versus allograft biopsies or the presence or absence of cell or antibody mediated rejection in biopsies showing histopathologic findings of TMA. However, in allograft biopies, 9/14 males and 2/12 females had ESRD due to HTN and/or DM (p=0.014). Other cases of ESRD in women included scleroderma, SLE, complications of pregnancy, drug toxicity, multiple myeloma and polycystic kidney disease.


In summary, we found that kidney biopsies showing histologic findings of TMA are indeed, more common in AA females, but this was not associated with a significantly worse outcome as the data suggests. We also note that in the transplant population of biopsies with TMA, hypertension and/or diabetes was a more common cause of ESRD in males of either ethnicity, rather than mirroring the general population with a higher preponderance in AA overall. This finding suggests that in women, allograft associated TMA could be related to predisposing factors. Further investigation with a larger cohort is required to support these findings.

 Males (# allograft)Females (# allograft)
AA13 (8)28 (10)
C14 (6)11 (2)