Visualization of lower extremity lymphedema in the same cohort using 99mTc-human serum albumin and 99mTc-phytate lymphoscintigraphy with SPECT-CT.

Lymphoscintigraphy with single-photon emission computed tomography (SPECT-CT) is useful in diagnosing lymphedema. However, there are multiple timings, techniques, and tracers utilized worldwide without any comparison. We examined and compared the image clarity with two different radiotracers, 99mTc human serum albumin (HSA) and 99mTc phytate (phytate), in the same patients. The study retrospectivity examined 46 limbs of 36 patients who underwent lymphoscintigraphy using HSA and phytate from January 2013 to September 2018. Tracer accumulation in the lymph nodes, linear pattern (LP), and dermal backflow (DBF) were qualitatively analyzed; contrast-to-noise ratios (CNR) of DBF and standardized uptake value ratio (SUVR) of LP were also quantitatively analyzed. Neither lymph node accumulation nor DBF identification showed significant difference. However, a significant difference was observed between the LP identification of the unaffected (p<0.001) and affected sides (p<0.001). On quantitative evaluation, CNR and SUVR of LP was significantly higher with HSA than with phytate (p<0.001). SUVR of LP was also significantly higher with HSA than with phytate in both unaffected (p=0.002) and affected (p=0.005) sides. Overall, images acquired with HSA were clearer than that with phytate, and the identification of LP was particularly better with HSA than with phytate. Thus, lymphoscintigraphy using HSA is preferred over phytate for both diagnosis and evaluation of disease severity and surgical site selection.

Eicosapentaenoic acid enhances skeletal muscle hypertrophy without altering the protein anabolic signaling pathway.

This study aimed to examine the effect of eicosapentaenoic acid (EPA) on skeletal muscle hypertrophy induced by muscle overload and the associated intracellular signaling pathways. Male C57BL/6J mice were randomly assigned to oral treatment with either EPA or corn oil for 6 weeks. After 4 weeks of treatment, the gastrocnemius muscle of the right hindlimb was surgically removed to overload the plantaris and soleus muscles for 1 or 2 weeks. We examined the effect of EPA on the signaling pathway associated with protein synthesis using the soleus muscles. According to our analysis of the compensatory muscle growth, EPA administration enhanced hypertrophy of the soleus muscle but not hypertrophy of the plantaris muscle. Nevertheless, EPA administration did not enhance the expression or phosphorylation of Akt, mechanistic target of rapamycin (mTOR), or S6 kinase (S6K) in the soleus muscle. In conclusion, EPA enhances skeletal muscle hypertrophy, which can be independent of changes in the AKT-mTOR-S6K pathway.

Risk of metachronous recurrence after endoscopic submucosal dissection of esophageal squamous cell carcinoma.

Development of endoscopic submucosal dissection (ESD) improves the en bloc resection rate of superficial esophageal squamous cell carcinoma (SESCC). Although the background mucosa after ESD remains malignant potential, esophageal (sub)circumferential ESD, in cases where the mucosal defect is greater than three-fourths of the circumference, might induce refractory stricture, and it may disturb early detection of the recurrence. Therefore, we aimed to elucidate whether the patients treated by (sub)circumferential ESD for SESCC may remain at risk of metachronous recurrence. In a single-center retrospective study, we collected data from 154 consecutive patients who were treated with curative ESD for SESCC from 2002 to 2013 and followed by surveillance for longer than 12 months. Metachronous recurrence was defined as histologically proven SESCC at other site of the ESD scar or abnormal nodal swelling was detected later than 12 months after ESD. The primary endpoint was to identify the risk of metachronous recurrence using multivariate analyses. The secondary endpoint was to investigate difference in clinical pathological features between patients with and without the recurrence. The overall rate of metachronous recurrence was 14.9% during 40.5 median months after the initial ESD. 24.1% and 9.0% of overall metachronous recurrence were observed in patients treated with (sub)circumferential ESD and non-subcircumferential ESD, respectively, despite no significant difference in their observation duration. After the application of a stepwise regression model that included all variants, a Cox proportional hazards regression model identified (sub)circumferential ESD as the only risk for the recurrence (hazard ratio (HR): 1.48, 95% confidence intervals (CI): 1.04-2.08, P = 0.028). The cumulative recurrence rate revealed a significant difference between patients treated by (sub)circumferential ESD and those by nonsubcircumferential ESD (HR: 3.094, 95% CI: 1.33-7.52, P = 0.009), despite no significant difference in their cause-specific survival. Additionally, the session numbers of the follow-up endoscopy until the detection of metachronous recurrence after the non-subcircumferential ESD were significantly less than those after the (sub)circumferential ESD (7.8 ± 1.8 vs. 15.2 ± 1.5 P = 0. 005), despite no significant difference in their cancer-free duration. In conclusion, we demonstrated that patients treated by curative (sub)circumferential ESD for SESCC might be high risk for metachronous recurrence. Therefore, we should establish a risk-stratified surveillance program after (sub)circumferential ESD and preventive strategies for post-ESD stricture.

Reducing glucocorticoid dosage improves serum osteocalcin in patients with rheumatoid arthritis-results from the TOMORROW study.

UNLABELLED: Decreasing the daily dose of glucocorticoids improved bone metabolic marker levels in patients with rheumatoid arthritis. However, changes in disease activity did not influence bone metabolism. Bone metabolism might thus remain uncontrolled even if disease activity is under good control. Decreasing glucocorticoid dosage appears important for improving bone metabolism. INTRODUCTION: Patients with rheumatoid arthritis (RA) develop osteoporosis more frequently than healthy individuals. Bone resorption is increased and bone formation is inhibited in patients with RA, and glucocorticoid negatively affects bone metabolism. We aimed to investigate factors influencing bone metabolic markers in patients with RA. METHODS: We started the 10-year prospective cohort Total Management of Risk Factors in Rheumatoid Arthritis Patients to Lower Morbidity and Mortality (TOMORROW) study in 2010. We compared changes in urinary cross-linked N-telopeptide of type I collagen (uNTx) and serum osteocalcin (OC), as markers of bone resorption and formation, respectively, in 202 RA patients and age- and sex-matched volunteers between 2010 and 2011. We also investigated factors influencing ΔuNTx and ΔOC in the RA group using multivariate analysis. RESULTS: Values of ΔuNTx were significantly lower in patients with RA than in healthy controls (-0.51 vs. 7.41 nmol bone collagen equivalents (BCE)/mmol creatinine (Cr); p = 0.0013), whereas ΔOC values were significantly higher in RA patients (0.94 vs. 0.37 ng/ml; p = 0.0065). Changes in prednisolone dosage correlated negatively with ΔOC (ß = -0.229, p = 0.001), whereas changes in disease activity score, bisphosphonate therapy, and period of biologics therapy did not correlate significantly with ΔOC. No significant correlation was seen between ΔuNTx and change in prednisolone dosage. CONCLUSIONS: Decreased glucocorticoid dosage improved bone metabolic markers in RA, but disease activity, bisphosphonate therapy, and period of biologics therapy did not influence levels of bone metabolic markers. Decreasing glucocorticoid dosage appears important for improving bone metabolic marker profiles in patients with RA.

Basophil infiltration in eosinophilic oesophagitis and proton pump inhibitor-responsive oesophageal eosinophilia.

BACKGROUND: The features of proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) are similar to those of eosinophilic oesophagitis (EoE), but PPI-REE demonstrates symptomatic and histological responses to PPI therapy. Several studies have shown that basophils play a crucial role in the pathogenesis of allergic diseases. AIM: To identify and compare basophil infiltration in the oesophageal epithelium in patients with EoE, PPI-REE, gastroesophageal reflux disease (GERD) and normal oesophagus (controls). METHODS: Biopsy specimens from 43 patients, including 12 with EoE, 11 with PPI-REE, 10 with GERD and 10 normal oesophagus, were analysed. Immunohistochemistry was performed to quantify the number of basophils and mast cells in the oesophageal epithelium. Double immunofluorescence staining for thymic stromal lymphopoietin (TSLP) and basophils was performed. Patients with EoE were treated with swallowed fluticasone. RESULTS: There were no differences in clinical, endoscopic or histological features between patients with EoE and PPI-REE. There were more basophils and mast cells in patients with EoE and PPI-REE than in patients with GERD and control subjects. Basophil infiltration of the oesophageal epithelium in patients with EoE was higher than that in patients with PPI-REE (3.6 ± 2.8 per high power field vs. 1.2 ± 0.9 per high power field respectively; P = 0.02); however, there was no significant difference in mast cell infiltration between the two groups. TSLP was highly expressed in the oesophageal epithelium in areas infiltrated by basophils. Steroid therapy significantly decreased intraepithelial basophils in patients with EoE. CONCLUSION: Basophils may play an important role in the pathogenesis of eosinophilic oesophagitis.

Identification of a high-risk group for low-dose aspirin-induced gastropathy by measuring serum pepsinogen in H. pylori-infected subjects.

BACKGROUND: We recently demonstrated in humans that the extent of low-dose aspirin (LDA)-induced gastropathy was directly related to the individual gastric acid secretion level. We also established reliable cutoff serum pepsinogen (PG) values to predict gastric acid secretion status. In this study, we investigated the clinical usefulness of measuring the serum pepsinogen values for identifying a high-risk group for gastric mucosal injury among chronic LDA users. METHODS: One hundred long-term LDA users were enrolled in this analysis. Serum from each subject was subjected to determination of H. pylori status and measurement of pepsinogen values. According to our recent report, a PG I value ≥ 50 ng/mL was defined as estimated hyperchlorhydria in H. pylori-negative subjects, while a PG I/II ≥ 3.3 was defined as estimated hyperchlorhydria in H. pylori-positive subjects. The grade of gastric mucosal injury was assessed endoscopically, and multiple logistic regression analyses were used to estimate the risk. RESULTS: Estimated hyperchlorhydria was a strong independent risk for intensive gastric mucosal injury with an OR (95% CI): 34.0 (4.5-259) and for gastric ulcer with an OR (95% CI): 10.2 (1.8-58.3) in H. pylori-positive subjects, while it was not a significant risk in H. pylori-negative subjects. The association persisted even after excluding those with conventional risks for LDA-gastropathy such as ulcer histories. CONCLUSION: Using simple serum measurement of H. pylori antibody and pepsinogen concentrations, an extremely high-risk group for LDA-induced gastropathy could be extracted, and these patients should become a therapeutic target for prevention of LDA-induced gastropathy.

Comprehensive data on ionising radiation from Fukushima Daiichi nuclear power plant in the town of Miharu, Fukushima Prefecture: The Misho Project.

Data related to radioactivity released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 15 March 2011 gathered by residents of Miharu, Fukushima Prefecture, and by Tohoku University are presented. These data sets consist of (1) the earliest radiation monitoring by a Geiger counter in the town, (2) ratios of radioactivity between (132)Te and (137)Cs for a wide area between Fukushima and Tokyo, (3) radiation measurement of soil samples collected from 18 school grounds, and (4) external radiation exposure of 1400 students using OSL badges. By combining and analysing these various data sets, a curve for the cumulative total external exposure as a function of time, with 16 : 00 h on 15 March 2011 being time zero, is obtained. The average cumulative external dosage is estimated to be 10 mSv (σ = 4.2 mSv) over 10 years. In addition, the initiative that the residents of Miharu took in response to the FDNPP accident, which became known as The Misho Project (MP), is documented; in particular, the time at which the municipality instructed the immediate ingestion of iodine tablets by those under the age of 40, 13 : 00 h on 15 March 2011, is assessed.

Feasibility of marrow harvesting from pediatric sibling donors without hematopoietic growth factors and allotransfusion.

We retrospectively studied 108 marrow harvests from 105 pediatric sibling donors. The median age of donors was 8 years (range: 1-15) and the median body weight was 27 kg (range: 10-100). The volumes of aspirated marrow were 5.0-23.8 mL/kg donor body weight, and harvested bone marrow volume exceeded 15 mL/kg in 42% of the donors. A total of 100 autologous blood donations were performed, and eight donors had red cells salvaged from their harvests reinfused. The median Hb levels before and after harvests were 12.3 g/dL (range: 10.0-14.7) and 11.0 g/dL (range: 8.9-13.8), respectively. None of the donors received allogeneic blood transfusions or hematopoietic growth factors such as EPO and G-CSF before or after collection. Transplanted dose was 1.4-10.8 × 10(8) cells/kg recipient body weight without differences due to donor age. Higher concentrations of nucleated and CD34(+) cells were obtained from younger donors. All donors tolerated the procedures well, with no serious complications. Thus, children may safely donate marrow for allogeneic transplantation, and the yields of nucleated cells for engraftment are substantial.

Serious laryngeal edema during endoscopic resection for squamous cell carcinoma of the esophagus.

The detection of early esophageal squamous cell carcinoma (ESCC) in patients following radiotherapy for squamous cell carcinoma of the head and neck (HNSCC) has increased with the development of endoscopic technologies. The aim of the current case - control study was to elucidate the risk factors of serious laryngeal edema, a lethal complication that occurs during endoscopic resection for ESCC. Among 184 consecutive patients who were treated by endoscopic resection for ESCC between January 2009 and May 2012, five of 22 patients with a history of radiotherapy for HNSCC suffered from serious laryngeal edema, which was not observed in patients who had not undergone radiotherapy. The susceptibility to serious laryngeal edema in patients with a history of radiotherapy followed by neck dissection for HNSCC was significantly greater than those without such histories. Despite the limited number of cases, we suggest that previous radiotherapy followed by neck dissection for HNSCC might be a predictive factor for serious laryngeal edema during endoscopic resection.

Human C-reactive protein enhances thrombus formation after neointimal balloon injury in transgenic rabbits.

BACKGROUND: High plasma levels of C-reactive protein (CRP) constitute a powerful predictive marker of cardiovascular events. Several lines of evidence suggest that CRP has prothrombogenic effects. However, whether CRP directly participates in the pathogenesis of thrombosis in vivo has not been fully clarified. OBJECTIVE: To test whether human CRP (hCRP) affects arterial thrombus formation after balloon injury of smooth muscle cell (SMC)-rich or macrophage-rich neointima. METHODS: We compared the susceptibility of transgenic (Tg) rabbits expressing hCRP (46.21 ± 13.85 mg L(-1), n = 22) and non-Tg rabbits to arterial thrombus formation after balloon injury of SMC-rich or macrophage-rich neointima. RESULTS: Thrombus size on SMC-rich or macrophage-rich neointima was significantly increased, and was accompanied by an increase in fibrin content in hCRP-Tg rabbits, as compared with non-Tg rabbits. Thrombus size did not significantly differ between SMC-rich and macrophage-rich neointima in hCRP-Tg rabbits. Tissue factor (TF) mRNA expression and activity in these neointimal lesions were significantly increased in hCRP-Tg rabbits as compared with non-Tg rabbits. The degree of CRP deposition correlated with the elevated TF expression and thrombus size on injured neointima. In addition, hCRP isolated from hCRP-Tg rabbit plasma induced TF mRNA expression and activity in rabbit cultured vascular SMCs. CONCLUSIONS: These results suggest that elevated plasma hCRP levels promote thrombus formation on injured SMC-rich neointima by enhancing TF expression, but have no additive effects in macrophage-rich neointima.

High incidence of fatty liver and insulin resistance in long-term adult survivors of childhood SCT.

Overweight/obesity among adult survivors of childhood SCT has been considered to be predictive of eventual development of metabolic abnormalities. Fatty liver is increasingly recognized as a major cause of liver-related morbidity and mortality in the general population. However, the real incidence of fatty liver in adult survivors of SCT has not been fully elucidated. We determined whether adult survivors are at risk for overweight/obesity, metabolic abnormalities and fatty liver and whether these risks are associated with cranial radiotherapy (CRT) before SCT. Among the 51 patients (30 males), only two male patients were overweight/obese at the last evaluation. On the other hand, 9 male (30%) and 15 female (71%) patients were underweight. Fatty liver was diagnosed in 11 male (37%) and 10 female (48%) patients during the follow-up period, although patients who had fatty liver did not tend to be overweight/obese. Significantly more patients who received CRT before SCT developed fatty liver with insulin resistance than those who did not (P<0.05). Even patients who are not overweight/obese may develop fatty liver and metabolic abnormalities. We recommend that healthcare professionals recognize these risks and give life-long attention to detecting, preventing and treating late complications after SCT.

Increased risk of bacterial infection after engraftment in patients treated with allogeneic bone marrow transplantation following reduced-intensity conditioning regimen.

Although bacterial infection is a major cause of death even after reduced-intensity conditioning (RIC) for allogeneic stem cell transplantation (SCT), little is known about the epidemiology and risk factors. The incidence of bacterial infection in 43 patients who received allogeneic bone marrow transplantation (BMT) using a RIC regimen was compared with that in 68 patients who received BMT using a myeloablative conditioning regimen, and risk factors for bacterial infection were identified. Before engraftment, incidences of febrile neutropenia (FN) and documented infections (DI) were significantly decreased in RIC patients (FN: 59.5% vs. 89.6%, P<0.01, DI: 4.8% vs. 17.9%, P<0.01). However, incidence of bacterial infection was significantly increased in RIC patients in the post-engraftment phase (53.8% vs. 11.1%, log-rank, P<0.01). Blood stream was the most frequent focus of infection in both groups. In multivariate analysis, RIC and acute graft-versus-host disease were revealed to be significant risk factors for bacterial infection in this phase. In summary, risk of bacterial infection after engraftment was significantly higher in RIC patients, although infection was decreased before engraftment, and we need to develop a RIC-specific strategy against bacterial infection after RIC SCT.

Discontinuation of infliximab after attaining low disease activity in patients with rheumatoid arthritis: RRR (remission induction by Remicade in RA) study.

BACKGROUND: Tumour necrosis factor (TNF) inhibitors enable tight control of disease activity in patients with rheumatoid arthritis (RA). Discontinuation of TNF inhibitors after acquisition of low disease activity (LDA) is important for safety and economic reasons. OBJECTIVE: To determine whether infliximab might be discontinued after achievement of LDA in patients with RA and to evaluate progression of articular destruction during the discontinuation. METHODS: 114 patients with RA who had received infliximab treatment, and whose Disease Activity Score, including a 28-joint count (DAS28) was <3.2 (LDA) for 24 weeks, were studied. RESULTS: The mean disease duration of the 114 patients was 5.9 years, mean DAS28 5.5 and mean modified total Sharp score (mTSS) 63.3. After maintaining LDA for >24 weeks by infliximab treatment, the drug was discontinued and DAS28 in 102 patients was evaluated at year 1. Fifty-six patients (55%) continued to have DAS28<3.2 and 43% reached DAS<2.6 at 1 year after discontinuing infliximab. For 46 patients remission induction by Remicade in RA (RRR) failed: disease in 29 patients flared within 1 year and DAS28 was >3.2 at year 1 in 17 patients. Yearly progression of mTSS (DeltaTSS) remained <0.5 in 67% and 44% of the RRR-achieved and RRR-failed groups, respectively. The estimated DeltamTSS was 0.3 and 1.6 and Health Assessment Questionnaire-Disability Index was 0.174 and 0.614 in the RRR-achieved and RRR-failed groups, respectively, 1 year after the discontinuation. CONCLUSION: After attaining LDA by infliximab, 56 (55%) of the 102 patients with RA were able to discontinue infliximab for >1 year without progression of radiological articular destruction.

Gastric hyposecretion in esophageal squamous-cell carcinomas.

Recently, gastric fundic atrophy is reported to be an independent risk factor for esophageal squamous-cell carcinoma (ESCC). The aim of this study is to investigate the acid secretory level in ESCC in a case-control study. From April 2004 to March 2008, 100 consecutive subjects with early ESCC and 100 age- and sex-matched asymptomatic controls were prospectively enrolled. Gastrin-stimulated acid output was assessed by endoscopic gastrin test. Conditional regression analyses were used to adjust for other potential confounders. Multivariate analyses revealed a strong association between profound hypochlorhydria and ESCC with odds ratio (95% confidence interval): 6.0 (1.9-18.4). The association remained significant after adjusting for the effect of gastric atrophy as a covariate. The association became stronger as the ESCC developed more distal site of the esophagus. This study indicates that profound hypochlorhydria is a strong independent risk factor for ESCC even after adjusting for the influence of gastric atrophy.

Protective mechanism of ultrafiltration against cardiopulmonary bypass-induced lung injury.

BACKGROUND: We previously demonstrated a negative effect of cardiopulmonary bypass (CPB) in a canine model of single-lung graft function and an improved effect with ultrafiltration during CPB. OBJECTIVE: To investigate the mechanism of these effects, focusing on cytokines and pulmonary surfactants using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). MATERIALS AND METHODS: Fifteen left-sided single-lung transplant procedures were performed in pairs of dogs. The animals were divided into 3 groups. In one group, transplantation was performed without CPB (non-CPB group); in a second group, transplantation was performed with CPB and CPB flow was decreased slowly and pulmonary artery pressure was controlled (CPB group; and in the third group, transplantation was performed with CPB and ultrafiltration (CPB+UF group). Grafted lung specimens were harvested for RT-PCR of cytokines (IL-6, IL-8, and IL-10) and surfactant proteins (SP-A, SP-B, and SP-C). RESULTS: Real-time quantitative RT-PCR demonstrated increased IL-6 expression in the CPB group compared with the non-CPB group. IL-6 gene expression was suppressed and pulmonary surfactant restored using ultrafiltration. Gene expression of surfactant protein (SP)-A, SP-B, and SP-C was decreased in the CPB group compared with normal lung and ultrafiltration groups, which demonstrated sustained gene expression of SP-A and SP-B. CONCLUSION: Cardiopulmonary bypass has negative effects on grafts; however, ultrafiltration attenuates acute lung dysfunction by decreasing the inflammatory response and increasing pulmonary surfactant.

[Single-stage operation for synchronous bilateral multiple lung cancer through median sternotomy].

An asymptomatic 65-year-old woman was incidentally found to have abnormal shadows on a chest X-ray during a medical examination. A chest computed tomography (CT) scan showed a pulmonary nodule in both right and left lung. Those were diagnosed as synchronous cStage IA bilateral lung cancer, and right upper lobectomy and segmentectomy of the left lung with lymphoadenectomy were sequentially performed through median sternotomy. The patient showed a favorable course after surgery, and was discharged on postoperative day 12. The pathological diagnosis was synchronous lung cancer and both were adenocarcinoma. The pathological stage was IA on the right side and IB on the left. A single-stage operation through median sternotomy was a useful surgical procedure for treating this case of synchronous bilateral lung cancer.

The adaptive responses in several mediators linked with hypertrophy and atrophy of skeletal muscle after lower limb unloading in humans.

AIM: To determine the adaptive changes in several molecules regulating muscle hypertrophy and atrophy after unloading, we examined whether unilateral lower limb suspension changes the mRNA and protein levels of SRF-linked (RhoA, RhoGDI, STARS and SRF), myostatin-linked (myostatin, Smad2, Smad3 and FLRG) and Foxo-linked (P-Akt, Foxo1, Foxo3a and Atrogin-1) mediators. METHODS: A single lower limb of each of eight healthy men was suspended for 20 days. Biopsy specimens were obtained from the vastus lateralis muscle pre- and post-suspension. RESULTS: The volume of the vastus lateralis muscle was significantly decreased after unloading. The amount of RhoA, RhoGDI or SRF protein in the muscle was not significantly changed post-suspension. An RT-PCR semiquantitative analysis showed increased levels of myostatin mRNA but not Smad2, Smad3 or FLRG mRNA. Unloading did not elicit significant changes in the amount of p-Smad3 or myostatin protein in the muscle. The amount of p-Akt protein was markedly reduced in the unloaded muscle. Lower limb SUSPENSION DID NOT INFLUENCE THE EXPRESSION PATTERN OF FOXO1, FOXO3A OR ATROGIN-1. CONCLUSION: Unloading inducing a mild degree of muscle atrophy may decrease p-Akt and increase myostatin but not SRF-linked mediators.

Complement activation in patients with primary antiphospholipid syndrome.

OBJECTIVE: To investigate the significance of complement activation in patients with primary antiphospholipid syndrome (APS). METHODS: Thirty-six patients with primary APS, 42 control patients with non-systemic lupus erythematosus (SLE) connective tissue diseases, and 36 healthy volunteers were analysed retrospectively. Serum complement levels (C3, C4, CH(50)) and anaphylatoxins (C3a, C4a, C5a) were examined in all subjects, and serum complement regulatory factors (factor H and factor I) were measured in patients with primary APS. Plasma anticoagulant activity was determined in a mixing test using the activated partial thromboplastin time. RESULTS: Serum complement levels were significantly lower in patients with primary APS than in patients with non-SLE connective tissue diseases (mean (SD) C3: 81.07 (17.86) vs 109.80 (22.76) mg/dl, p<0.001; C4: 13.04 (8.49) vs 21.70 (6.96) mg/dl, p<0.001; CH(50): 31.32 (8.76) vs 41.40 (7.70) U/ml, p<0.001) or healthy volunteers. Only two healthy subjects with low serum C4 levels showed hypocomplementaemia, whereas most patients with primary APS showed raised serum C3a and C4a. No subjects showed raised C5a. Patients with primary APS with low serum C3 or C4 had significantly higher levels of C3a or C4a than healthy controls. No patients had low serum complement regulatory factors. Among patients with primary APS, hypocomplementaemia was significantly more common in those with high anticoagulant activity than in those with low or normal activity. CONCLUSION: Hypocomplementaemia is common in patients with primary APS, reflecting complement activation and consumption, and was correlated with anticoagulant activity, suggesting that antiphospholipid antibodies may activate monocytes and macrophages via anaphylatoxins produced in complement activation.