Factors That Influence the Quality of RNA From the Pancreas of Organ Donors

Abstract

Objectives: Attaining high-quality RNA from the tissues or organs of deceased donors used for research can be challenging due to physiological and logistical considerations. In this investigation, METHODS: RNA Integrity Number (RIN) was determined in pancreatic samples from 236 organ donors and used to define high (≥6.5) and low (≤4.5) quality RNAs. Logistic regression was used to evaluate the potential effects of novel or established organ and donor factors on RIN.

Results: Univariate analysis revealed donor cause of death (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.15-0.77; P = 0.01), prolonged tissue storage before RNA extraction (OR, 0.65; 95% CI, 0.52-0.79; P < 0.01), pancreas region sampled (multiple comparisons, P < 0.01), and sample type (OR, 0.32; 95% CI, 0.15-0.67; P < 0.01) negatively influenced outcome. Conversely, duration of final hospitalization (OR, 3.95; 95% CI, 1.59-10.37; P < 0.01) and sample collection protocol (OR, 8.48; 95% CI, 3.96-19.30; P < 0.01) positively impacted outcome. Islet RNA obtained via laser capture microdissection improved RIN when compared with total pancreatic RNA from the same donor (ΔRIN = 1.3; 95% CI, 0.6-2.0; P < 0.01).

Conclusions: A multivariable model demonstrates that autopsy-free and biopsy-free human pancreata received, processed, and preserved at a single center, using optimized procedures, from organ donors dying of anoxia with normal lipase levels increase the odds of obtaining high-quality RNA.

Figure 1. Comparison of RIN Values from Islet and Total RNA using the Same Donor Pancreas

RIN values from total RNA (both low and high quality) were compared to those from LCM islets obtained from the same pancreas (n=37 donors). In 9 cases (blue), RIN from total RNA was found to be a median of 16.7 absolute percentage points higher (4.3 min, 55.6 max) than that of islet RNA. In 28 cases (red), RIN from islet RNA was found to be 55.3 percentage points higher (6.9, 122.4) than that of total RNA.