Clinicopathologic Findings in COVID-19-Associated Ischemic Enterocolitis

Aims

Coronavirus disease 2019 (COVID‐19) has been recognised as a predominantly respiratory tract infection, but some patients manifest severe systemic symptoms/coagulation abnormalities. The aim of this study was to evaluate the impact of severe COVID‐19 infection on the gastrointestinal tract.

Methods and results

We examined clinicopathological findings in 28 resected ischaemic bowels from 22 patients with severe COVID‐19. Most patients required intubation preoperatively and presented with acute decompensation shortly before surgery. D‐dimer levels were markedly elevated in all measured cases (mean, 5394 ng/ml). Histologically, 25 cases (19 patients) showed evidence of acute ischaemia with necrosis. In this group, the most characteristic finding was the presence of small vessel fibrin thrombi (24 of 25 cases, 96%), which were numerous in 64% of cases. Patients with COVID‐19 were significantly more likely than a control cohort of 35 non‐COVID‐19‐associated acute ischaemic bowels to show isolated small intestine involvement (32% versus 6%, P < 0.001), small vessel fibrin thrombi (100% versus 43%, P < 0.001), submucosal vessels with fibrinous degeneration and perivascular neutrophils (90% versus 54%, P < 0.001), fibrin strands within submucosal vessels (58% versus 20%, P = 0.007), and histological evidence of pneumatosis (74% versus 34%, P = 0.010). Three cases in this cohort had histopathological findings normally seen in the setting of chronic ischaemia, notably prominent fibroblastic proliferation affecting the outer layer of the muscularis propria.

Conclusions

Herein, we describe the histopathological findings in COVID‐19‐associated ischaemic bowels and postulate a relationship with the hypercoagulable state seen in patients with severe COVID‐19 infection. Additional experience with these cases may further elucidate specific features or mechanisms of COVID‐19‐associated ischaemic enterocolitis.

Placental Pathology in COVID-19: Case Series in a Community Hospital Setting

Objective

To report the histopathologic findings in the placentas of pregnant women with coronavirus disease-19 (COVID-19).

Methods

Pregnant women with COVID-19 delivering between April 2020 to June 2020 were identified. A retrospective study of placentas from COVID positive women received in the Department of Pathology, Monmouth Medical Center affiliate of Robert Wood Johnson Barnabas Health were examined and compared to control cohort of placentas from COVID negative women. The mothers were tested for coronavirus through nasopharyngeal swab upon admission to labor and delivery. The placentas from mothers who tested negative for the virus were sent to Pathology for examination based on the obstetrician’s clinical judgment.

Results

Fifty surgical specimens (49 placentas and one product of conception) from patients positive for COVID-19 were examined and compared with fifty placentas from women with negative COVID-19 test results, who delivered during the same period. Most of the neonates had Appearance, Pulse, Grimace, Activity and Respiration (APGAR) scores of 9 and 9 at 1 and 5 minutes, respectively. Increased incidence of the COVID-19 positivity was noted in individuals with Rh-positive blood group A and Jewish heritage. Compared to the control group, the COVID-19 positive placentas showed increased features of malperfusion (microcalcifications, fibrin thrombi, syncytial knotting, and villous agglutination). However, there was no significant dysregulation in other variables, such as inflammation or coagulation. There was no case of maternal or fetal death (greater than eight weeks) or evidence of worse fetal outcomes noted due to a mother's positive COVID-19 status. 

Conclusions

The COVID-19 positive placentas showed an increased prevalence of microcalcifications and fibrin thrombi, which may reflect an underlying hypercoagulable state induced by COVID-19 infection or could be due to excessive syncytiotrophoblast injury.

Fibrin thrombi in deceased donor kidneys: Prevalence and influence on graft function and graft survival in transplanted patients

Fibrin thrombi (FT) are occasionally found in the pre-implantation biopsy of kidneys from deceased donors. The aim of this study was to monitor the prevalence and answer the question whether FT has any impact on future graft function in a Danish patient cohort. We looked for FT in all donor kidney biopsies taken at the time of renal transplantation in a Danish transplantation unit during a 10-year period. Every recipient transplanted with a FT donor kidney (n = 15) were matched with up to five control recipients (n = 69), and graft function and graft survival were assessed. FT was present in 3% of the transplanted donor kidneys. Graft function was reduced in the FT group 6 months after transplantation (median estimated glomerular filtration rate (eGFR): 29 mL/min vs 46 mL/min; p = 0.017), but at 12 months, an apparent difference did not reach statistical significance. More patients were on dialysis in the FT group after 12 months compared with the control group (27% vs 6%; p = 0.049). In conclusion, FT in donor kidney biopsies at time of transplantation is a risk factor for the development of reduced renal function during the first year of transplantation.