Investigation of MHC gamma block C4A and C4B polymorphisms in unrelated hematopoietic stem cell transplantation

ABSTRACT Background: Immunological life-threatening complications frequently occur in post-hematopoietic stem cell transplantation (HSCT), despite matching recipient and donor (R/D) pairs for classical human leukocyte antigens (HLA). Studies have shown that R/D non-HLA disparities within the major histocompatibility complex (MHC) are associated with adverse effects post-HSCT. Methods: We investigated the impact of mismatches of single-nucleotide polymorphisms (SNPs) in C4A/C4B genes, for showing the highest diversity in the MHC gamma block, on 238 patients who underwent HLA 10/10 unrelated donor (URD) HSCT. The endpoints were acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD) and mortality. One hundred and twenty-nine R/D pairs had 23 C4-SNPs typed by PCR-SSP (Gamma-Type™v.1.0), and 109 R/D pairs had these 23 SNPs identified by next-generation sequencing (NGS) using the Illumina platform. Results: The percentage of patients who received HSC from HLA 10/10 donors with 1-7 mismatches was 42.9%. The R/D pairs were considered C4 mismatched when bearing at least one disparity. These mismatches were not found to be risk factors for aGVHD, cGVHD or mortality after unrelated HSCT when SNPs were analyzed together (matched or mm ≥ 1), independently or according to the percentage of incompatibilities (full match for 23 SNPs; 1-3 mm and >3 mm). An exception was the association between 1-3 mismatches at the composite of SNPs C13193/T14952/T19588 with the development of aGVHD (P = 0.012) and with grades III-IV of this disease (P = 0.004). Conclusion: Our data are not consistent with the hypothesis that disparities in C4A/C4B SNPs increase the risks of post-HSCT adverse effects for the endpoints investigated in this study.

Impact of C4, C4A and C4B gene copy number variation in the susceptibility, phenotype and progression of systemic lupus erythematosus

Abstract Background Complement component 4 (C4) gene copy number (GCN) affects the susceptibility to systemic lupus erythematosus (SLE) in different populations, however the possible phenotype significance remains to be determined. This study aimed to associate C4A , C4B and total C4 GCN and SLE, focusing on the clinical phenotype and disease progression. Methods C4 , C4A and C4B GCN were determined by real-time PCR in 427 SLE patients and 301 healthy controls, which underwent a detailed clinical evaluation according to a pre-established protocol. Results The risk of developing SLE was 2.62 times higher in subjects with low total C4 GCN (< 4 copies, OR = 2.62, CI = 1.77 to 3.87, p < 0.001) and 3.59 times higher in subjects with low C4A GCN (< 2 copies; OR = 3.59, CI = 2.15 to 5.99, p < 0.001) compared to those subjects with normal or high GCN of total C4 (≥4) and C4A (≥2), respectively. An increased risk was also observed regarding low C4B GCN, albeit to a lesser degree (OR = 1.46, CI = 1.03 to 2.08, p = 0.03). Furthermore, subjects with low C4A GCN had higher permanent disease damage as assessed by the Systemic Lupus International Collaborating Clinics - Damage Index (SLICC-DI; median = 1.5, 95% CI = 1.2-1.9) than patients with normal or high copy number of C4A (median = 1.0, 95% CI = 0.8-1.1; p = 0.004). There was a negative association between low C4A GCN and serositis ( p = 0.02) as well as between low C4B GCN and arthritis ( p = 0.02). Conclusions This study confirms the association between low C4 GCN and SLE susceptibility, and originally demonstrates an association between low C4A GCN and disease severity.

The expressions and clinical significance of complements 3, 4B1 and apolipoprotein E in pancreatic cancer / 中华消化杂志

Objective To investigate the expressions of complements 3 (C3), 4B1 (C4B1) and apolipoprotein E (ApoE) in pancreatic cancer and relations with TNM staging and lymph node metastasis of pancreatic cancer. Methods Thirty-eight pancreatic cancer biopsy specimens, 20 fresh pancreatic cancer specimens and 20 adjacent normal tissues of pancreatic cancer were collected. The expressions of C3, C4B1, ApoE in pancreatic cancers and normal pancreatic tissues were detected by immunohistochemistry and Western-Blot, the positive expression rates of C3, C4B1, ApoE and the differences in gray scale were also observed. Their association with pancreatic cancer TNM staging and lymph node metastasis were analyzed by SPSS 13.0. Results The expression rates of C3, C4B1, ApoE in pancreatic cancer were 73.68% (28/38), 86.84%(29/38) and 76.31% (33/38) respectively, higher than those in normal pancreatic tissues which were 42.11% (16/38), 26.32% (10/38) and 42.11% (16/38) accordingly, the differences were statistically significant (χ2 was 7.77, 19.01, 16.6, and P value were 0.01, 0.00, 0.00 respectively). The gray scale of C3, C4B1 and ApoE in pancreatic cancer were 1.63±0.28,1.25±0.18 and 2.57±0.22 respectively, higher than those in normal pancreatic tissue (0.88±0.19,0.65±0.13,1.28±0.24 respectively), the differences were statistically significant (t value were 9.93,11.81,17.71 and all P value were 0.00, respectively). There was no association between C3 and TNM staging or lymphatic metastasis of pancreatic cancer. C4B1 and ApoE were closely related with TNM stage and lymph node metastases. The expressions of C4B1 and ApoE in stage Ⅱ to Ⅳ pancreatic cancer or with lymphatic metastasis were significantly higher than those in stage Ⅰpancreatic cancer and those without lymph node metastasis. Conclusion C3, C4B1 and ApoE were all highly expressed in pancreatic cancer. C3 was only involved in early event in pancreatic cancer, not related with development of pancreatic cancer. C4B1 and ApoE were involved in tumor growth and metastasis.

Apolipoprotein E and complement C4b1 expressions and its significance in human pancreatic carcinoma / 中华胰腺病杂志

Objective To investigate the expression of apolipoprotein E (ApoE) and complement C4b1 in pancreatic carcinoma and study its significance. Methods Immunohistochemistry was used to detect the expression of ApoE and C4b1 protein in 38 cases of pancreatic carcinoma tissues and adjacent normal pancreatic tissues, and RT-PCR was used to detect the expression of ApoE and C4b1 mRNA in 20 cases of pancreatic carcinoma tissues and adjancent normal pancreatic tissues. The relevance of ApoE and C4b1 expressions to the biological features of pancreatic carcinoma were analyzed. Results The positive rates of ApoE and C4b1 expressions are 86.8% (33/38) and 76.3% (29/38) in pancreatic carcinoma, respectively,which were significantly higher than those in normal pancreatic tissues [42.1% (16/38) and 26.3% ( 10/38 ),P ＜ 0.01]. The positive rates of ApoE and C4b1 expressions [78.3% ( 18/23 ) and 73.9% ( 17/23 )] in patients with metastasis were significantly higher than in those without metastasis [(33.3% (5/15) and 40.0%(6/15), P ＜ 0.05). Significantly higher expressions of ApoE and C4b1 mRNA were noted in pancreatic carcinoma(4.83 ± 0.65 and 7.94 ± 0. 95 ) than those in the normal pancreatic tissue ( 1.78 ± 0.74and 1.22 ±0.57, P ＜ 0.01 ), and patients with metastasis showed significantly higher expression of ApoE and C4b1 mRNA (5.05 ±0.71 and 8.24 ± 1.07) than those without metastasis (4.42 ±0.25 and 7.39 ±0.15,P ＜ 0.05). Conclusions ApoE and C4b1 were highly expressed in pancreatic cancer, and may be closely related with lymph node metastasis.