Preformed vs de novo anti-human leukocyte antigens-DQ antibodies in kidney transplantation: A retrospective study

Table 1 Immunological and clinical overview of patients with de novo anti-human leukocyte antigen-DQ donor-specific antibodies

Clinical case	Sex	Age	Graft origin/relationship/transplantation date	HLA typing	Immunizing events	Crossmatch	Post-transplant antibodies to HLA I/II	Rejection diagnosis
1	Male	52	LD/spouse/transplanted in 2013	R: A*23/A*33; B*15/B*44; DRB1*01/DRB1*15; DQB1: NT	None: Not immunized pre-transplant	Negative	3 years post TR: Only DSA anti HLA-DQ de novo; DQB1*02:01 ==> MFI 9581; DQB1*03:01 ==> MFI 6962	Proven humoral rejection (biopsy)
				D: A*01/A*02; B*07/B*08; DRB1*03/NT; DQB1*02/DQB1*03
2	Male	49	LD/mother/transplanted in 2014	R: A*02/NT; B*38/B*52; DRB1*08/DRB1*15; DQB1*06/DQB1*06	None: Not immunized pre-transplant	Negative	3 years post TR: Only DSA anti HLA-DQ de novo; DQB1*02:01 ==> MFI 16317; DQB1*02:02 ==> MFI 14917	Proven humoral rejection (biopsy)
				D: A*02/A*29; B*38/B*45; DRB1*08/DRB1*09; DQB1*02/DQB1*06
3	Female	25	LD/mother/transplanted in 2013	R: A*03/A*68; B*14/NT; DRB1*11/DRB1*11; DQB1*03/NT	2 transfusions: Not immunized pre-transplant	Negative	6 years post TR: DSA anti HLA-DQ de novo; DQB1*03:02 ==> MFI 19473; DQB1*03:03 ==> MFI 8663 Associated with DSA A2 ==> MFI 7004	Proven humoral rejection (biopsy)
				D: A*02/A*68; B*14/B*21; DRB1*07/DRB1*11; DQB1*03/NT
4	Male	40	LD/spouse/transplanted in December 2025	R: A*24/A*29; B*44/B*50; DRB1*15/DRB1*15; DQB1*06/DQB1*06	None: DSA anti DR4 (MFI 123)	Negative	4 years post TR: Only DSA anti HLA-DQ de novo; MFI 10189 < DQB1*02 < MFI 12029	Proven humoral rejection (biopsy)
				D: A*01/A*02; B*08/B*18; DRB1*03/DRB1*04; DQB1*02/DQB1*04
5	Male	55	LD/sister/transplanted in 2016	R: A*68/NT; B*18/NT; DRB1*02/NT; DQB1*02/NT	None: Not immunized pre-transplant	Negative	17 months post TR: DSA anti HLA-DQ de novo; DQB1*06 ==> MFI 17963 Associated with: MFI 4870 < DSA A*66 < MFI 14271; DSA B*27 ==> MFI 19112	Proven humoral rejection (biopsy)
				D: A*68/A*66; B*18/B*27; DRB1*03/DRB1*15; DQB1*02/DQB1*06
6	Female	54	LD /sister/transplanted in November 2016	R: A*01/A*02; B*07/B*50; DRB1*03/NT; DQB1: NT	2 transfusions/2 pregnancies: A32 (MFI 1600), DR16 (MFI 1103)	Negative	6 months post TR: Only DSA anti HLA-DQ de novo; DQA1*05:01 ==> MFI 599	Suspicion of humoral rejection
				D: A*24/A*30; B*13/B*51; DRB1*07/DRB1*11; DQB1*02/DQB1*03; DQA1*02/DQA1*05

LD: Living donor; NT: Not typed; TR: Kidney transplantation; DSA: Donor-specific antibody; HLA: Human leukocyte antigen; MFI: Median fluorescence intensity.