An Unusual Presentation of Pyelonephritis: Is It COVID-19 Related?

In severe cases of COVID-19, late complications such as coagulopathy and organ injury are increasingly described. In milder cases of the disease, the exact time frame and causal path of late-onset complications have not yet been determined. Although direct and indirect renal injury by SARS-CoV-2 has been confirmed, hemorrhagic renal infection or coagulative problems in the urinary tract have not yet been described. This case report describes a 35-year-old female without relevant medical history who, five days after having recovered from infection with SARS-CoV-2, had an unusual course of acute pyelonephritis of the right kidney and persistent fever under targeted antibiotic treatment. A hemorrhagic ureteral obstruction and severe swollen renal parenchyma preceded the onset of fever and was related to the developing pyelonephritis. Sudden thrombotic venous occlusion in the right eye appeared during admission. Symmetrical paresthesia in the limbs in combination with severe lower back pain and gastro-intestinal complaints also occurred and remained unexplained despite thorough investigation. We present the unusual combination of culture-confirmed bacterial hemorrhagic pyelonephritis with a blood clot in the proximal right ureter, complicated by retinal vein thrombosis, in a patient who had recovered from SARS-CoV-2-infection five days before presentation. The case is suspect of a COVID-19-related etiology.

Decreased expression of ligands of placental immune checkpoint inhibitors in uncomplicated and preeclamptic oocyte donation pregnancies.

Oocyte donation (OD) pregnancies are characterized by a complete immunogenetic dissimilarity between mother and fetus, which requires enhanced immunoregulation compared to naturally conceived (NC) pregnancies. The trophoblast expresses co-inhibitory ligands crucial for regulation of the maternal T cell response. Therefore, we studied the role of placental immune checkpoint inhibitors for the establishment of fetal tolerance and their relation to the development of preeclampsia in OD compared to NC pregnancies. Placental tissue from uncomplicated OD (n = 21) and NC (n = 21) pregnancies, and OD (n = 9) and NC (n = 15) pregnancies complicated with preeclampsia were studied. Protein expression of co-inhibitory ligands PD-L1 and CD200 was double blind semi-quantitatively determined by immunohistochemistry. Messenger RNA expression of PD-L1, CD200 and indoleamine 2,3-dioxygenase (IDO) was determined using qPCR. Decreased PD-L1 and CD200 protein expression and increased IDO mRNA expression was observed in uncomplicated OD versus NC pregnancies (all p < 0.05). CD200 protein expression was positively correlated with PD-L1 expression in all groups, with the number of HLA total mismatches and with HLA class I mismatches in uncomplicated OD cases (all p < 0.05). Preeclamptic cases showed lower PD-L1 protein and CD200 protein and mRNA expression in OD compared to NC pregnancies (all p < 0.05). This study shows that signaling by co-inhibitory PD-L1 and CD200 and by immunosuppressive IDO is altered in the placenta of OD pregnancies, suggesting a contribution to the higher risk for preeclampsia. These insights provide future prospects in unraveling the immune paradox of oocyte pregnancy, which are applicable for better risk management and treatment of uncomplicated and preeclamptic pregnancies.