Minimal Change Disease Secondary to Either COVID-19 Infection or Pfizer-BioNTech COVID-19 Vaccination

Introduction/Objective

Kidney injury has now become one of the known complications following COVID-19 infection and vaccination. Only few cases of minimal change disease following administration of COVID-19 vaccination and infection have been reported. This study was to highlight incidence of minimal change disease following COVID-19 infection or vaccination.

Methods/Case Report

Case 1:15 year-old female with past medical history of asthma and hypercholesterolemia presented for evaluation of periorbital edema, nephrotic-range proteinuria, hypoalbuminemia, elevated serum creatinine, elevated blood pressures, and hematuria after COVID-19 infection. Renal biopsy after 1 week of infection showed unremarkable glomeruli and negative immunofluorescent stains in glomeruli, and 20-30% fusion of foot processes. The biopsy was consistent with a minimal change disease with features of natural remission (her nephrotic-range proteinuria resolved soon after). Case 2: 18 year-old female with no significant past medical history presented with a chief complaint of generalized swelling, which started around the same time she received her 1st dose of Pfizer COVID vaccine (the 2nd dose 2 months later). She had a nephrotic range proteinuria and hypoalbuminemia, but normal level of serum creatinine. A renal biopsy after 4 months of vaccination showed unremarkable glomeruli by light microscopy, negative immunofluorescent study, but diffuse effacement of foot processes involving more than 80% of the examined loops by electron microscopy. This biopsy findings were consistent with a minimal change disease. Both patients did not receive any treatment before the renal biopsies.

Results (if a Case Study enter NA)

NA

Conclusion

Minimal change disease can be a rare complication following COVID-19 infection or Pfizer COVID-19 vaccination, raising a question if there are similar antigens induced by the infection or by the vaccination that trigger the minimal change disease. Further studies are needed to determine the incidence and pathophysiology of minimal change disease either post COVID-19 vaccines or following COVID-19 infections.

There Is High Sensitive and Specific Correlation Between Frozen and Permanent Sections in Renal Transplant Biopsies

INTRODUCTION

Frozen sections have been used for evaluating tumors and margins during daily practice in pathology with high specificity and sensitivity (>90% for both indices both at national level and in our department). The correlation between frozen section tissue for immunofluorescent (IF) studies and permanent sections for light microscopy, along with electron microscopy, is critical for constructing a final renal pathology diagnosis.

METHODS

We studied the correlation between the frozen sections for IF studies and separate fragments of tissue for permanent light microscopic sections in our renal transplant biopsies for purposes of quality control. Frozen sections for IF sections were compared with permanent sections for light microscopy in 122 renal transplant biopsies, using inflammation as the key criterion (63 with no inflammation and 59 with inflammation) to determine the correlation.

RESULTS

There was high sensitivity (94.9%) and specificity (92.1%) for the correlation between the frozen section and permanent sections.

CONCLUSIONS

Our data suggest that parts of renal transplant biopsy tissue dissected to freeze for IF studies and for light microscopy were highly correlated to ensure a high quality of renal tissue dissection for the final diagnosis in renal transplant biopsies.

Feasibility of BK Virus Real-Time PCR Testing in Renal Graft Biopsies With Negative SV40 Staining

BACKGROUND

BK virus (BKV)-associated nephropathy (BKVAN) is often associated with renal graft dysfunction. When renal transplant recipients present with high clinical suspicion for BKVAN (high serum and urine BKV titer with graft dysfunction) but their graft biopsies stain negatively for BKV, non-correlated situations between the two tests often lead to a dilemma about how to treat them.

METHODS

This retrospective investigation was conducted to determine how real-time quantitative PCR (qPCR) for BKV, routinely applied to serum and urine, could be helpful in identifying the existing BKV in biopsy tissue stained negatively for BKV.

RESULTS

DNA was extracted from each specimen through the use of five 10-μm curls from the tissue block with use of the QIAamp DNA FFPE Tissue Kit (Qiagen), followed by BKV qPCR to determine copies of BKV/μg of biopsy tissue DNA. Group 1 (11 negative renal controls for BKV) demonstrated 0 to 9 BKV copies/μg DNA. Except for 3 focally staining cases showing low BKV, the remaining 10 positive renal controls in group 2 (13 positive transplant biopsies staining positively) demonstrated elevated BKV up to 160 million copies/μg DNA. Group 3 transplants (13 uncertain transplants with negative BKV staining but positive liquid BKV) were negative for BKV (0-12 copies/μg) in 4 of 13, had low BKV copies (36-346 copies/μg) in 5 of 13, and had high BKV copies (17,240-526,945 copies/μg) in 4 of 13 cases, through the use of qPCR.

CONCLUSIONS

The data indicate that qPCR from paraffin-embedded tissue as a backup test is sensitive for ruling in/out BKV infection in renal transplant biopsies, particularly in uncertain cases.