C1q Dominant Deposits in Renal Transplant Biopsies Are Not Associated with Allograft Dysfunction

A. Babu¹, S. Williamson², N. Khoury¹, M. Safwan¹, A. Patel¹

¹Transplant Institute, Henry Ford Hospitals, Detroit, MI, ²Pathology Surgical, Henry Ford Hospitals, Detroit, MI

Meeting: 2019 American Transplant Congress

Abstract number: C19

Keywords: Biopsy, Kidney, Protocol biopsy

Topic:

Session Information

Session Name: Poster Session C: Innate Immunity; Chemokines, Cytokines, Complement

Date: Monday, June 3, 2019

Session Time: 6:00pm-7:00pm

Presentation Time: 6:00pm-7:00pm

Location: Hall C & D

*Purpose: Complement deposition in renal allograft biopsies and native kidneys may represent an ongoing inflammatory process. We studied the significance of incidental finding of predominant C1q deposits in the renal allograft biopsies on renal function, proteinuria, and graft survival.

*Methods: Retrospectively, patients who have undergone renal biopsies either protocol or for cause were retrieved for the last five years. Eight patients were found to have dominant or codominant C1q deposits. Patients without C1q deposits (n=21) were selected from the same time period as a control group. Demographic data, creatinine, proteinuria, graft survival data were collected from the electronic medical records.

*Results: Our analysis included 8 cases with predominant C1q deposits and 21 controls without C1q deposits. Cause of end stage renal disease included type 2 diabetes in 4 cases, type 1 diabetes 1 case, 2 cases had chronic GN, 1 case APRT enzyme deficiency. There were no differences in age, duration on dialysis, HLA mismatch, or induction/maintenance immunosuppressive agents. At one year follow up there was no difference in creatinine or incidence of proteinuria. There were no graft loss in the cases. Potentially deceptive pathologic findings included kappa light chain predominance in deposits of 1 case (without glomerular morphologic alterations) and tubuloreticular structures by electron microscopy in another (without clinical evidence of lupus).

*Conclusions: In this well-characterized cohort of patients with dominant C1q deposits in the mesangium, there was no association with renal allograft dysfunction or proteinuria. In this short follow up there was no effect on allograft survival. We conclude that there is no clinical relevance of isolated predominant C1q deposit in short-term follow-up. This is in line with one other published study. Further studies are needed to look for long-term effects of C1q deposits and if these lesions persist or disappear in subsequent biopsies.

Characteristics
Variable	Cases n=8	Controls n=21	p value
Age, mean (SD)	46 (13.59)	52.38 (9.7)	0.17
Dialysis months, Mean (SD)	37.3 (45.56)	42.86 (44.11)	0.77
HLA MM, mean (SD)	3.75 (1.39)	4.33 (0.97)	0.21
Creatinine, mean (SD)	1.19 (0.36)	1.44 (0.44)	0.18
Proteinuria, mean (SD)	0.1 (NA)	0.43 (0.38)	0.25
Graft Loss, n (%)	0	1(5)	0.55

To cite this abstract in AMA style:

Babu A, Williamson S, Khoury N, Safwan M, Patel A. C1q Dominant Deposits in Renal Transplant Biopsies Are Not Associated with Allograft Dysfunction [abstract]. Am J Transplant. 2019; 19 (suppl 3). https://atcmeetingabstracts.com/abstract/c1q-dominant-deposits-in-renal-transplant-biopsies-are-not-associated-with-allograft-dysfunction/. Accessed September 25, 2021.

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