A Web-Based Prediction Model for Estimating the Probability of Post-hepatectomy Major Complications in Patients with Hepatocellular Carcinoma: A Multicenter Study from a Hepatitis B Virus-Endemic Area.

BACKGROUND: The identification of patients at high risk of developing postoperative complications is important to improve surgical safety. We sought to develop an individualized tool to predict post-hepatectomy major complications in hepatitis B virus (HBV)-infected patients with hepatocellular carcinoma (HCC). METHODS: A multicenter database of patients undergoing hepatectomy for HCC were analyzed; 2/3 and 1/3 of patients were assigned to the training and validation cohorts, respectively. Independent risks of postoperative 30-day major complications (Clavien-Dindo grades III-V) were identified and used to construct a web-based prediction model, which predictive accuracy was assessed using C-index and calibration curves, which was further validated by the validation cohort and compared with conventional scores. RESULTS: Among 2762 patients, 391 (14.2%) developed major complications after hepatectomy. Diabetes mellitus, concurrent hepatitis C virus infection, HCC beyond the Milan criteria, cirrhosis, preoperative HBV-DNA level, albumin-bilirubin (ALBI), and aspartate transaminase to platelet ratio index (APRI) were identified as independent predictors of developing major complications, which were used to construct the online calculator ( http://www.asapcalculate.top/Cal11_en.html ). This model demonstrated good calibration and discrimination, with the C-indexes of 0.752 and 0.743 in the training and validation cohorts, respectively, which were significantly higher than those conventional scores (the training and validation cohorts: 0.565 ~ 0.650 and 0.568 ~ 0.614, all P < 0.001). CONCLUSIONS: A web-based prediction model was developed to predict the probability of post-hepatectomy major complications in an individual HBV-infected patient with HCC. It can be used easily in the real-world clinical setting to help management-related decision-making and early warning, especially in areas with endemic HBV infection.

Association of Adjuvant Radiation Therapy With Long-Term Overall and Recurrence-Free Survival After Hepatectomy for Hepatocellular Carcinoma: A Multicenter Propensity-Matched Study.

PURPOSE: R0 resection with a wide surgical margin is the gold standard for hepatocellular carcinoma (HCC), yet R0 resection with narrow margins and even R1 resection is not uncommon in real-world clinical practice. We sought to use a propensity-matched analysis to characterize the efficacy of adjuvant radiation therapy on long-term oncological survival after hepatectomy for HCC with narrow or positive margins. METHODS AND MATERIALS: Using a multi-institutional database, patients with HCC who underwent hepatectomy with negative margins of 0.1 to 1.0 cm or pathologically positive margins were analyzed. Using propensity score matching (PSM) and multivariate Cox-regression analysis, the effect of adjuvant radiation therapy on long-term overall survival (OS) and recurrence-free survival (RFS) was evaluated. RESULTS: Among 683 patients who met inclusion criteria, 82 patients received adjuvant radiation therapy within 10 weeks after surgery. Radiation therapy-related major toxic effects were minimal among patients receiving adjuvant radiation therapy. PSM analysis created 78 matched pairs of patients. In the PSM cohort, median OS and RFS among patients treated with adjuvant radiation therapy were more favorable than individuals who were not treated (72.5 and 37.3 months versus 52.5 and 24.0 months, both P < .05). After adjustment for other confounding factors on multivariate analyses, adjuvant radiation therapy remained independently associated with favorable OS and RFS after hepatectomy with close/positive surgical margins for HCC (hazard ratios, 0.821 and 0.827, respectively). CONCLUSIONS: Despite the lack of consensus on the role of adjuvant radiation therapy after HCC resection, this PSM analysis suggested improved OS and RFS with adjuvant radiation therapy after hepatectomy with close/positive surgical margins for HCC. Future randomized controlled trials are needed to further define the survival benefit of adjuvant radiation therapy for patients with HCC.

Association of Preoperative Body Mass Index with Surgical Textbook Outcomes Following Hepatectomy for Hepatocellular Carcinoma: A Multicenter Study of 1206 Patients.

BACKGROUND: Assessment of quality in the perioperative period is critical to ensure good patient care. Textbook outcomes (TO) have been proposed to combine several parameters into a single defined quality metric. The association of preoperative body mass index (BMI) with incidences of achieving or not achieving TO (non-TO) among patients undergoing hepatectomy for hepatocellular carcinoma (HCC) was characterized. METHODS: Patients who underwent curative-intent hepatectomy for HCC between 2015 and 2018 were identified from a multicenter database. These patients were divided into three groups based on preoperative BMI: low-BMI (≤ 18.4 kg/m2), normal-BMI (18.5-24.9 kg/m2), and high-BMI (≥ 25.0 kg/m2). The incidences of non-TO among these three groups were compared. Multivariate analyses were performed to identify whether there was any independent association between preoperative BMI and non-TO. RESULTS: Among 1206 patients, 100 (8.3%), 660 (54.7%), and 446 (37.0%) were in the low-BMI, normal-BMI, and high-BMI groups, respectively. The incidence of non-TO was 65.6% in the whole cohort. The incidence of non-TO was significantly higher among patients in the low- and high-BMI cohorts versus the normal-BMI cohort (75.0% and 74.7% versus 58.0%, both P < 0.01). After adjustment of other confounding factors on multivariate analysis, low-BMI and high-BMI were independently associated with higher incidences of non-TO compared with normal-BMI (OR: 1.98 and 2.27, both P < 0.05). CONCLUSIONS: Two out of three patients did not achieve TO after hepatectomy for HCC. Both preoperative low-BMI and high-BMI were independently associated with lower odds to achieve optimal TO following HCC resection.

Clinical Features of Recurrence After Hepatic Resection for Early-Stage Hepatocellular Carcinoma and Long-Term Survival Outcomes of Patients with Recurrence: A Multi-institutional Analysis.

BACKGROUND: A potentially curative hepatic resection is the optimal treatment for hepatocellular carcinoma (HCC), but most HCCs, even at an early stage, eventually recur after resection. This study investigates clinical features of initial recurrence and long-term prognosis of patients with recurrence after curative resection for early-stage HCC. PATIENTS AND METHODS: From a multicenter database, patients who underwent curative hepatic resection for early-stage HCC [Barcelona Clinic Liver Cancer (BCLC) stage 0/A] were extracted. Time to initial recurrence, patterns of initial recurrence, and treatment modalities for recurrent tumors were investigated. Univariate and multivariate analysis were used to identify independent risks associated with postoperative recurrence, as well as post-recurrence survival (PRS) for patients with recurrence. RESULTS: Among 1424 patients, 679 (47.7%) developed recurrence at a median follow-up of 54.8 months, including 408 (60.1%) early recurrence (≤ 2 years after surgery) and 271 (39.9%) late recurrence (> 2 years). Independent risks of postoperative recurrence included cirrhosis, preoperative alpha-fetoprotein level > 400 ug/L, tumor size > 5 cm, multiple tumors, satellites, microvascular invasion, and intraoperative blood transfusion. Multivariate analysis revealed that receiving irregular recurrence surveillance, initial tumor beyond Milan criteria, early recurrence, BCLC stage B/C of the recurrent tumor, and noncurative treatments were independently associated with poorer PRS. CONCLUSIONS: Nearly half of patients with early-stage HCC experienced recurrence after resection. Understanding recurrence risks may help identify patients at high risk of recurrence who may benefit from future adjuvant therapies. Meaningful survival even after recurrence can still be achieved by postoperative regular surveillance and curative treatment.

Long-term oncological prognosis after curative-intent liver resection for hepatocellular carcinoma in the young versus the elderly: multicentre propensity score-matching study.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common malignancy in the elderly worldwide, but it is also common among younger individuals in areas with endemic hepatitis B virus infection. The differences in long-term oncological prognosis of young versus elderly patients after R0 liver resection for HCC were explored in this study. METHODS: Using a Chinese multicentre database, consecutive patients who underwent R0 liver resection for HCC between 2007 and 2019 were analysed retrospectively. After excluding middle-aged (36-69 years old) patients, overall survival (OS), cancer-specific survival (CSS), and recurrence were compared between young (35 years or younger) and elderly (70 years or older) patients using propensity score matching (PSM). RESULTS: Among 531 enrolled patients, there were 192 (36.2 per cent) and 339 (63.8 per cent) patients categorized as young and elderly respectively. PSM created 140 pairs of matched patients. In the PSM cohort, 5-year OS was comparable for young versus elderly patients (51.7 versus 52.3 per cent, P = 0.533). Young patients, however, had a higher 5-year cumulative recurrence rate (62.1 versus 51.6 per cent, P = 0.011) and a worse 5-year CSS rate (54.0 versus 64.3 per cent, P = 0.034) than elderly patients. On multivariable Cox regression analyses, young patient age remained independently associated with an increased recurrence rate (hazard ratio 1.62, P = 0.016) and a decreased CSS rate (hazard ratio 1.69, P = 0.021) compared with older age. CONCLUSION: Following R0 liver resection for HCC, younger patients were at a higher risk of recurrence, and elderly patients had a better CSS rate. Thus, enhanced surveillance for HCC recurrence should be implemented for young patients.

Impact of concurrent splenectomy and esophagogastric devascularization on surgical outcomes of partial hepatectomy for hepatocellular carcinoma in patients with clinically significant portal hypertension: A multicenter propensity score matching analysis.

PURPOSE: Portal hypertension due to cirrhosis is common among patients with hepatocellular carcinoma (HCC). This study aimed to compare the outcomes of partial hepatectomy in patients with HCC and clinically significant portal hypertension (CSPH) with or without concurrent splenectomy and esophagogastric devascularization (CSED). PATIENTS AND METHODS: From a multicenter database, patients with HCC and CSPH who underwent curative-intent hepatectomy were identified. Postoperative morbidity and mortality, and long-term overall survival (OS) were compared in patients with and without CSED before and after propensity score matching (PSM). RESULTS: Of the 358 enrolled patients, 86 patients underwent CSED. Before PSM, the postoperative 30-day morbidity and mortality rates were comparable between the CSED and non-CSED group (both P > 0.05). Using PSM, 81 pairs of patients were created. In the PSM cohort, the 5-year OS rate of the CSED group were significantly better than the non-CSED group (52.9% vs. 36.5%, P= 0.046). The former group had a significantly lower rate of variceal bleeding on follow-up (7.4% vs. 21.7%, P= 0.014). On multivariate analysis, CSED was associated with significantly better OS (HR: 0.39, P < 0.001). CONCLUSION: Hepatectomy and CSED can safely be performed in selected patients with HCC and CSPH, which could improve postoperative prognosis by preventing variceal bleeding, and prolonging long-term survival.

Risk factors for hepatic insufficiency after major hepatectomy in non-cirrhotic patients.

It is very necessary for patients with liver cancer to reasonably apply the prediction method of liver failure after hepatectomy before liver surgery. Liver surgeons can benefit greatly from clinical activities.

Major Hepatectomy in Elderly Patients with Large Hepatocellular Carcinoma: A Multicenter Retrospective Observational Study.

BACKGROUND: With an increase in life expectancy and improvement of surgical safety, more elderly patients with hepatocellular carcinoma (HCC), even with large tumors, are now considered for hepatectomy. This study aimed to clarify the impact of age on short- and long-term outcomes after major hepatectomy (≥3 segments) for large HCC (≥5 cm). PATIENTS AND METHODS: Using a multicenter database, patients who underwent curative-intent major hepatectomy for large HCC between 2006 and 2016 were identified. Postoperative morbidity and mortality, overall survival (OS) and recurrence-free survival (RFS) were compared between the elderly (≥65 years) and younger (<65 years) patients. Univariable and multivariable Cox-regression analyses were performed to identify the risk factors of OS and RFS in the entire and elderly cohorts, respectively. RESULTS: Of 830 patients, 92 (11.1%) and 738 (88.9%) were elderly and younger patients, respectively. There were no significant differences in postoperative 30-day mortality and morbidity between the two groups (5.4% vs 2.6% and 43.5% vs 38.3%, both P>0.05). The 5-year OS and RFS rates in elderly patients were also comparable to younger patients (35.0% vs 33.2% and 20.0% vs 20.8%, both P>0.05). In the entire cohort, multivariable Cox-regression analyses identified that old age was not independently associated with OS and RFS. However, in the elderly cohort, preoperative alpha-fetoprotein level >400 µg/L, multiple tumors, macrovascular invasion and microvascular invasion were independently associated with decreased OS and RFS. CONCLUSION: Carefully selected elderly patients benefited from major hepatectomy for large HCC as much as younger patients, and their long-term prognosis was determined by preoperative alpha-fetoprotein level, tumor number and presence of macro- or micro-vascular invasion.

[Plasma mannan?binding lectin and MBL?associated serine protease 2 in patients with hepatocellular carcinoma].

OBJECTIVE: To detect the plasma levels of mannan?binding lectin (MBL) and MBL?associated serine protease?2 (MASP-2) in patients with hepatocellular carcinoma (HCC) and explore their role in the tumorigenesis and progression of HCC. METHODS: The plasma levels of MBL and MASP?2 were detected by enzyme?linked immunosorbent assay in 64 HCC patients and 30 healthy control subjects. The correlation of MBL and MASP?2 with the clinical parameters of HCC patients were analyzed. RESULTS: The plasma levels of MBL (P=0.014) and MASP?2 (P=0.002) were significantly higher in HCC patients than in the healthy controls, but the MBL?to?MASP?2 ratio did not differ significantly between the two groups. In HCC patients, plasma MBL level was positively correlated with vascular invasion (r=0.253, P=0.047) and total bilirubin level (r=0.283, P=0.024). The plasma level of MASP?2 was positively correlated with TNM stage (r=0.276, P=0.027) and negatively correlated with plasma albumin level (r=0.?0.317, P=0.015). ROC curve analysis revealed an area under curve of 0.665 for MBL (P=0.010) and 0.694 for MASP?2 (P=0.003). The sensitivities of MBL and MASP?2 were 50% and 89.1% in the diagnosis of HCC, respectively. CONCLUSION: MBL and MASP?2 are associated with the inflammatory state and disease progression in patients with HCC.

Development and evaluation of a double antibody sandwich ELISA for the detection of human sDC-SIGN.

sDC-SIGN is the soluble form of dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN, CD209), which is a molecule involved with pathogen recognition and immune regulation. However, there is no commercially available ELISA kit for detecting human sDC-SIGN, and the normal range of this molecule is unknown. Here, we describe an ELISA for detecting human sDC-SIGN with high specificity. First, sDC-SIGN protein was expressed and purified. Monoclonal and polyclonal antibodies were then raised against the purified protein and subsequently characterized. A sandwich ELISA was developed using polyclonal antibodies specific for sDC-SIGN for capture and a biotin-labeled monoclonal antibody specific for sDC-SIGN for detection of protein. This method has sensitivity up to 0.2 ng/ml. Using this ELISA, we found that the concentration of sDC-SIGN in sera of healthy volunteers ranges from 0-319 ng/ml with a mean concentration of 27.14 ng/ml. Interestingly, the concentration of sDC-SIGN in sera from patients with cancer or chronic hepatitis B virus (CHB) infection was lower than that of health controls. The mean concentrations of sDC-SIGN in cancer patients and chronic hepatitis B virus infection patients were 3.2 ng/ml and 3.8 ng/ml, respectively. We developed a sandwich ELISA for detecting human sDC-SIGN and demonstrated its use by assessing sera concentrations of sDC-SIGN in patients with cancer and chronic CHB infection compared to that of healthy controls.

Mannan-binding lectin at supraphysiological concentrations inhibits differentiation of dendritic cells from human CD14+ monocytes.

Mannan-binding lectin (MBL), a circulating C-type lectin, is an important member of the defense collagen family. It exhibits a high potential for recognizing broad categories of pathogen-associated molecular patterns and initiating complement cascade responses. DCs are well-known specialist antigen-presenting cells that significantly trigger specific T cell-mediated immune responses. In our previous study, it was observed that high concentrations of MBL significantly attenuate LPS-induced maturation of monocyte-derived DCs (MoDCs). In the current study, it was postulated that MBL at similar supraphysiological concentrations would affect early differentiation of MoDCs in some way. CD14(+) monocytes from human peripheral blood mononuclear cells were cultured with granulocyte-macrophage colony-stimulating factor and IL-4 in the presence or absence of physiological (1 µg/mL) and supraphysiological concentrations (20 µg/mL) of MBL protein, respectively. Phenotypic analysis indicated that the differentiated DCs incubated with high concentrations of MBL expressed MHC class II and costimulatory molecules (e.g., CD80 and CD40) more weakly than did control groups. The secretion of IL-10 and IL-6 increased markedly, whereas their mixed lymphocyte reaction-stimulating capacity decreased. Members of the signal transducer and activator of transcription family were also found to be differentially regulated. Thus, beyond the role of MBL as an opsonin, our data reveal a possible inhibitory effect of MBL at high concentrations in monocyte-DC transition, which probably provides one way of regulating adaptive immune responses by strict regulation of DCs, making MBL a better prospect for controlling relevant pathological events such as autoimmune diseases.

Mutual blood donation is safer at small blood collection stations in China.

BACKGROUND: The assumption that the level of safety of voluntary non-remunerated donors is significantly higher than that of family replacement donors is supported by global data without stratifying for first-time or repeat volunteer, or according to age, but the viral marker prevalence between replacement donors and first-time voluntary non-remunerated donors is similar. MATERIALS AND METHODS: From 2006 to 2013, replacement and voluntary donors were respectively recruited by the hospitals and the Center Blood Station in Zhaoqing, Guangdong, according to the existing procedures, and all the donors were screened for hepatitis B virus (HBV) surface antigen (HBsAg), antibodies against hepatitis C virus (anti-HCV), human immunodeficiency virus (anti-HIV) (1 + 2) and Treponema pallidum (anti-TP) by the enzyme immunoassays (EIAs), and alanine aminotransferase (ALT) in the Center Blood Station by kinetic analysis method. The risk factors related to blood safety were analyzed by Binary logistic regression analysis. RESULTS: Between 252,202 volunteers and 2771 replacement donors, the prevalences of ALT > 40 U/L and anti-HIV (4.88% and 0.01% vs 4.44% and 0.07%, respectively) were not significantly different. The prevalences of HBsAg, anti-HCV and anti-syphilis in replacement group were higher than those in voluntary group, which were related to donor's sex, age and donation time. Overall prevalence of serological markers was higher in male replacement donors than in female, and in replacement donor over 30 years than in those below 30 years, but the positive prevalence in repeated replacement donors was lower than that in first-time replacement donors. CONCLUSIONS: With appropriate intervention measures, such as pre-donor screening and other donor selection policy, replacement donors and voluntary donors provide a similar level of viral safety. Our donor selection policy in future should focus on retaining both young replacement and young voluntary donors as repeat donors and promoting the donation proportion of females, which will improve blood safety.

A novel water-soluble benzothiazole derivative BD926 inhibits human activated T cell proliferation by down-regulating the STAT5 activation.

Immunosuppressants are widely used for treatment of T cell-mediated autoimmune diseases and allogeneic graft rejection. However, because of the toxicity and tolerance of these drugs, novel immunosuppressants are urgently needed. We synthesized a series of novel water-soluble benzothiazole derivatives and found that BD926 [sodium 2-(benzo[d]thiazol-2-yl)-4,5,6,7-tetrahydro-2H-indazol-3-olate] had potent immunosuppressive activity. Treatment with BD926 significantly inhibited anti-CD3/anti-CD28 and alloantigen-induced human T cell proliferation as well as IL2-stimulated activated T cell proliferation in a dose-dependent manner in vitro. BD926 had no obvious cytotoxicity against human resting T cells, IL-4 treated activated T cells and fibroblast-like synoviocytes in our experimental conditions. Furthermore, BD926 induced cell cycle arrest at G0/G1 phase and inhibited the cyclin D3 and CDK 6 expression in activated T cells. BD926 inhibited the STAT5, but not Akt and p70S6K, phosphorylation in a dose-dependent manner in the IL-2-treated activated T cells. Interestingly, BD926 inhibited IFN-γ, IL-6 and IL-17, but not IL-2, IL-4 and IL-10, production in activated T cells. Finally, treatment with BD926 reduced delayed-type hypersensitivity in mice in a dose-dependent manner. Collectively, these data suggest that BD926 may be a lead compound for the design and development of new immunosuppressants for the intervention of allograft rejection and autoimmune diseases.

[Human soluble dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin inhibits phagocytosis of Staphylococcus aureus by immature dendritic cells].

OBJECTIVE: To study the effect and mechanism of soluble dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (sDC-SIGN) on the phagocytosis of Staphylococcus aureus (S. aureus) by immature dendritic cells (imDCs). METHODS: Flow cytometry was employed to examine the effect of sDC-SIGN on the phagocytosis of S. aureus by imDCs. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the binging of sDC-SIGN to S. aureus, lipoteichoic acid (LTA) and lipopolysaccharides (LPS) and investigate the effect of the ligands mannan and LTA and anti-DC-SIGN antibodies 1C6 and 4H3 on the binging of sDC-SIGN to S. aureus. RESULTS: sDC-SIGN inhibited the phagocytosis of S. aureus by imDCs. sDC-SIGN bound to S. aureus in a Ca(2+)-dependent manner. sDC-SIGN concentration-dependently bound to LTA, but not to LTA, and the binging of sDC-SIGN to S. aureus was blocked by mannan, LTA, 1C6 and 4H3. CONCLUSION: sDC-SIGN preferentially binds to the carbohydrate constituents on S. aureus to affect the binding between membrane-bound DC-SIGN and S. aureus, thus suppressing the phagocytosis of S. aureus by imDCs.

Mannose-binding lectin inhibits monocyte proliferation through transforming growth factor-ß1 and p38 signaling pathways.

Mannose-binding lectin (MBL), a plasma C-type lectin, plays an important role in innate immunity. However, the interaction, and the consequences of it, between MBL and the immune system remain ill defined. We have investigated the contributing mechanisms and effects of MBL on the proliferation of human monocytes. At lower concentrations (≤4 µg/ml) MBL was shown to partially enhance monocyte proliferation. By contrast, at higher concentrations (8-20 µg/ml) of MBL, cell proliferation was markedly attenuated. MBL-induced growth inhibition was associated with G0/G1 arrest, down-regulation of cyclin D1/D3, cyclin-dependent kinase (Cdk) 2/Cdk4 and up-regulation of the Cdk inhibitory protein Cip1/p21. Additionally, MBL induced apoptosis, and did so through caspase-3 activation and poly ADP-ribose polymerase (PARP) cleavage. Moreover, transforming growth factor (TGF)-ß1 levels increased in the supernatants of MBL-stimulated monocyte cultures. We also found that MBL-dependent inhibition of monocyte proliferation could be reversed by the TGF-ß receptor antagonist SB-431542, or by anti-TGF-ß1 antibody, or by the mitogen-activated protein kinase (MAPK) inhibitors specific for p38 (SB203580), but not ERK (U0126) or JNK (SP600125). Thus, at high concentrations, MBL can affect the immune system by inhibiting monocyte proliferation, which suggests that MBL may exhibit anti-inflammatory effects.

Evaluation of the effects of homologous platelet gel on healing lower extremity wounds in patients with diabetes.

The treatment of chronic diabetic wounds remains complicated, despite new insight into the cellular and molecular basis of wound healing and cutaneous regeneration. A growing body of clinical trials has shown that platelet release has a notable effectiveness on refractory ulcer healing. However, patients with chronic diabetic ulcers usually have poor general health, and the large-volume blood absence required to produce autologous platelet-rich plasma often causes adverse effects. To overcome the limitation, the homologous platelet gel (PG) from healthy donor was used for the treatment of chronic diabetic lower extremity wound in the study. We show here that homologous derived platelets significantly enhanced EVC304 cell and HaCaT cell proliferation and homologous PG was capable of prompting cell migration. Twenty-one patients with refractory diabetic lower extremity ulcers, who had no response to conventional treatments, were treated in this study. Our data indicated that homologous PG was effective for the enhancement and acceleration of diabetic lower extremity wounds healing. We propose that homologous PG appeared to enhance vascularization and epithelialization, which might induce a quicker healing process and and encourage controlled studies in future.

Defective activities, but not secretions, resulting from gene point mutations of human mannan-binding lectin.

Human mannan-binding lectin (MBL) plays a pivotal role in innate immunity. Substantial literature supports the belief that three point mutations, CGT52TGT, GGC54GAC and GGA57GAA, in the collagen-like region (CLR) of the human MBL gene, are associated with increased susceptibility to infection, autoimmunity and carcinogenesis. To investigate the mechanisms of MBL deficiency, human wild-type and three variant MBL genes were expressed in COS-7 and Chinese hamster ovary (CHO) cells. Results showed that no apparent differences were found among the levels of gene transcription and protein secretion of four forms of MBL. However, the degree of oligomerization of variant forms of MBL was found to be much lower than that of recombinant human wild-type MBL. The ability of variant MBL proteins to bind mannan was much weaker than that of the wild-type MBL protein, and the MBL variants failed to effectively activate the complement lectin pathway. These data suggested that a lower order oligomer, but not decreased plasma levels of MBL, may be the main result of MBL gene mutations and may be associated with immunodeficiency.