Impact of technically qualified surgeons on laparoscopic colorectal resection outcomes: results of a propensity score-matching analysis.

BACKGROUND: The Endoscopic Surgical Skill Qualification System (ESSQS) was introduced in Japan to improve the quality of laparoscopic surgery. This cohort study investigated the short- and long-term postoperative outcomes of colorectal cancer laparoscopic procedures performed by or with qualified surgeons compared with outcomes for unqualified surgeons. METHODS: All laparoscopic colorectal resections performed from 2010 to 2013 in 11 Japanese hospitals were reviewed retrospectively. The procedures were categorized as performed by surgeons with or without the ESSQS qualification and patients' clinical, pathological and surgical features were used to match subgroups using propensity scoring. Outcome measures included postoperative and long-term results. RESULTS: Overall, 1428 procedures were analysed; 586 procedures were performed with ESSQS-qualified surgeons and 842 were done by ESSQS-unqualified surgeons. Upon matching, two cohorts of 426 patients were selected for comparison of short-term results. A prevalence of rectal resection (50·3 versus 40·5 per cent; P < 0·001) and shorter duration of surgery (230 versus 238 min; P = 0·045) was reported for the ESSQS group. Intraoperative and postoperative complication and reoperation rates were significantly lower in the ESSQS group than in the non-ESSQS group (1·2 versus 3·6 per cent, P = 0·014; 4·6 versus 7·5 per cent, P = 0·025; 1·9 versus 3·9 per cent, P = 0·023, respectively). These findings were confirmed after propensity score matching. Cox regression analysis found that non-attendance of ESSQS-qualified surgeons (hazard ratio 12·30, 95 per cent c.i. 1·28 to 119·10; P = 0·038) was independently associated with local recurrence in patients with stage II disease. CONCLUSION: Laparoscopic colorectal procedures performed with ESSQS-qualified surgeons showed improved postoperative results. Further studies are needed to investigate the impact of the qualification on long-term oncological outcomes.

ANTECEDENTES: El Sistema de Certificación de Habilidades Quirúrgicas Endoscópicas (Endoscopic Surgical Skill Qualification System, ESSQS) fue introducido en Japón para mejorar la calidad de la cirugía laparoscópica. En este estudio de cohortes se investigaron los resultados postoperatorios a corto y a largo plazo de las intervenciones laparoscópicas de cáncer colorrectal realizadas por o con la asistencia de cirujanos con certificación en comparación con cirujanos no certificados. MÉTODOS: Todas las resecciones colorrectales laparoscópicas realizadas entre 2010 y 2013 en 11 hospitales japoneses fueron revisadas retrospectivamente. Los procedimientos se clasificaron en función de si habían sido realizados por cirujanos con o sin certificación del ESSQS, y las características clínicas, patológicas y quirúrgicas de los pacientes se utilizaron para emparejar los subgrupos mediante puntuaciones de propensión. Las variables de resultado incluyeron los resultados postoperatorios y a largo plazo RESULTADOS: En total se analizaron 1.428 procedimientos, incluyendo 586 y 842 procedimientos realizados con y sin cirujanos certificados por ESSQS, respectivamente. Tras el emparejamiento, se seleccionaron dos cohortes de 426 pacientes para la comparación de resultados a corto plazo. Se observó una mayor prevalencia de resecciones rectales (50,3% versus 40,1%, P = 0,0001) y un tiempo quirúrgico más corto (230 versus 238 min, P = 0,04) en el grupo ESSQS. Las tasas de complicaciones intra- y postoperatorias y de reoperaciones fueron significativamente más bajas en el grupo ESSQS que en el grupo no ESSQS (1,2%, 4,6% y 1,9% versus 3,6%, 7,5% y 3,9%, P = 0,01; 0,03, y 0,02, respectivamente). Estos hallazgos se confirmaron tras el análisis de emparejamiento por puntaje de propensión. El análisis de regresión de Cox mostró que la no participación de cirujanos certificados con ESSQS (razón de oportunidades, odds ratio, OR 12,3; i.c. del 95%, 1,28-119,1; P = 0,03) se asoció independientemente con la recidiva local en los casos en estadio II. CONCLUSIÓN: Los procedimientos colorrectales laparoscópicos realizados por cirujanos certificados por ESSQS presentaron mejores resultados postoperatorios. Son necesarios más estudios para determinar el impacto de la certificación en los resultados oncológicos a largo plazo.

Broadly reactive antibodies to hypervariable region 1 in hepatitis C virus-infected patient sera: relation to viral loads and response to interferon.

To clarify the nature of serum anti-hypervariable region 1 (HVR1) antibodies in patients infected with hepatitis C virus (HCV), we assessed the reactivity of 21 patients' sera with 42 HVR1 proteins by Western blot. HVR1 was expressed as fusion proteins with glutathione S-transferase (GST). The patients' sera reacted with variable percentages of the HVR1 proteins, and always reacted with HVR1 proteins of the different genotype. In the genotype-1b-infected patients, the percentage of genotype-1b HVR1 proteins reactive with serum correlated significantly with viral loads; the sera reactive with the higher percentages of HVR1 proteins contained the larger viral loads. In addition, it was significantly lower in the responders of interferon (IFN) therapy than in nonresponders. The competition assays indicated that multiple fractions of anti-HVR1 antibodies with different specificity in a serum reacted with different HVR1 proteins, and that, additionally, a single fraction of antibodies often reacted with more than one HVR1 protein through a similar amino acid sequence. In conclusion, serum anti-HVR1 antibodies were broadly reactive by the mechanism of both the cross-reactivity of a single fraction of anti-HVR1 antibodies with more than one HVR1 protein and the presence of multiple fractions of anti-HVR1 antibodies with different specificity in a serum. In genotype-1b-infected patients, the broad reactivity of serum anti-HVR1 antibodies correlated with viral loads and response to IFN. Further studies are necessary to elucidate the correlation among the broad reactivity of sera with multiple HVR1 proteins and clinical features of chronic hepatitis C patients.

Different constitution of hepatitis C virus population in peripheral blood mononuclear cells and plasma in patients with type C chronic liver disease.

We searched for the presence of the plus or minus strand of hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells (PBMCs) from three patients with chronic HCV infection using the strand-specific reverse transcription and polymerase chain reaction (RT-PCR) method. To examine whether the HCV population of PBMCs differs from that of plasma, a sequence of the hypervariable region (HVR) in the E2/NS1 region was analyzed. All three patients had both plus and minus strands of HCV RNA in their PBMCs. Sequence study revealed that the HCV population in PBMCs was homogeneous in all patients, while that in plasma was composed of two main clones. One of these had the same sequence as the clones seen in PBMCs, except for one patient. Our results suggest that PBMCs represent one of the extrahepatic replication sites of HCV and that tissue tropism is expressed by some of the HCV population.

Serial quantitation of serum core protein and viral RNA of hepatitis C virus after interferon therapy: increase in viral loads in biochemical responders.

OBJECTIVES: Interferon (IFN) therapy is often ineffective in eradicating hepatitis C virus (HCV). Some patients show normal serum ALT levels for a long time after IFN therapy despite the presence of HCV. These patients are considered not virological responders but biochemical responders. We investigated the changes in the amount of HCV after IFN therapy in biochemical responders. METHODS: Nine biochemical responders and 11 nonresponders were studied. Serum HCV amount was measured by fluorescence enzyme immunoassay for HCV core (pg/ml) and Amplicor HCV Monitor test for HCV RNA (logarithms of copy numbers per milliliter). RESULTS: In biochemical responders, core protein and HCV RNA were increased significantly at 1 month after IFN therapy (291 +/- 191 pg/ml and 5.4 +/- 0.9, respectively; p < 0.05 for both) and at 1 yr (324 +/- 189 pg/ml and 5.6 +/- 0.7, respectively; p < 0.01 for both) compared with pretreatment values (122 +/- 114 pg/ml and 4.8 +/- 0.9, respectively). The change ratios of core protein at 1 month and 6 months after therapy to the pretreatment values were significantly higher in biochemical responders (3.2 +/- 2.4 and 2.9 +/- 2.3, respectively) than in nonresponders (0.9 +/- 0.7 and 1.1 +/- 0.8, respectively) (p < 0.05 for both). Similarly, the change ratios of HCV RNA at 1 month and 1 yr after IFN therapy were significantly higher in biochemical responders (9.9 +/- 14.6 and 12.8 +/- 15.1) than in nonresponders (0.6 +/- 0.5 and 1.2 +/- 1.2) (p < 0.05 for both). CONCLUSIONS: HCV amount increased significantly after IFN therapy in biochemical responders, whereas it did not change notably in nonresponders.

Earlier loss of hepatitis C virus RNA in interferon therapy can predict a long-term response in chronic hepatitis C.

To distinguish responders from non-responders early in interferon (IFN) treatment would be beneficial in patients with chronic hepatitis C. Those patients unlikely to respond would be spared the cost and hazard of prolonged treatment. Forty-three chronic hepatitis C patients who had received IFN-alpha therapy (6-9 MU; six times weekly for 2 weeks followed by thrice weekly for 22 additional weeks) were randomly enrolled into the present study. Serially obtained sera were retrospectively tested for HCV-RNA by reverse transcription-polymerase chain reaction (Amplicor HCV) with a low limit detection of approximately 10(2) copies/mL. Genotypes were determined by type-specific primers. Sixteen subjects were defined as sustained responders (SR), who showed sustained loss of viraemia with normalized alanine aminotransferase values for at least 6 months of follow-up after completion of therapy. The other 27 subjects were non-responders (NR), whose viraemia persisted during follow-up. Pretreatment serum HCV-RNA levels (P < 0.0001) and the genotype (P < 0.01) were significant predictors for sustained response to IFN therapy. Hepatitis C virus RNA was detectable in only one (6%) SR and in 23 (85%) NR at the second week of therapy (P < 0.0001) and was detected in none of the SR subjects and in 18 (67%) NR at the fourth week of therapy (P < 0.0001). Pretreatment viral load was correlated with the time until loss of viraemia. Multivariate analysis revealed that loss of viraemia at the second week of therapy was the strongest predictor for a long-term response, followed by the initial viral load and loss of viraemia at the fourth week of therapy. These findings suggest that it is possible to predict a long-term response to IFN as early as at the second and fourth weeks after the start of therapy by identifying the presence or absence of HCV-RNA with a sensitive assay.

Humoral immune response to the hypervariable region of hepatitis C virus differs between genotypes 1b and 2a.

Antibody to the hypervariable region (HVR) of HCV is thought to have neutralizing activity. The HCV genotype is known to affect the clinical course of infection. The antibody response to HVR and its relationship to the virologic and clinical characteristics were investigated in 21 patients with chronic hepatitis C. HVRs amplified by polymerase chain reaction from serum HCV were expressed as glutathione S-transferase fusion proteins. From 8 to 34 clones per serum sample were obtained (375 clones total), and the anti-HVR antibody in serum was assessed by Western blot. Both the incidence of fusion proteins positive for anti-HVR antibody and the activity of antibody were significantly higher in 6 patients with genotype 2a than in 15 patients with genotype 1b. This result suggests that the quantity of humoral response to HVR affects the clinical outcome of infection with these two HCV genotypes.

Cyclosporine therapy affects aminotransferase activity but not hepatitis C virus RNA levels in chronic hepatitis C.

Interferon (IFN) therapy is of proven efficacy in chronic hepatitis C, but it is not universally effective and is often limited by side effects. Cyclosporine A (CsA) is a potent immunosuppressant widely used in organ transplantation. We conducted a pilot study to determine whether CsA therapy could affect aminotransferase activity and hepatitis C virus RNA levels in patients with chronic hepatitis C. Cyclosporine A was administered to 10 patients (mean age of 59 years; male:female = 9:1) who did not respond to IFN therapy previously and who had elevated serum alanine aminotransferase (ALT) values for at least 6 months. All patients were positive for HCV-RNA by RT-PCR with genotype 1b. Their mean duration of hepatitis was 15 years. Oral CsA was given for 3 months in a dose that was increased at 1 month intervals from 1.5-2.0 to 2.0-3.0 and 3.0-4.0 mg/kg per day. All patients completed the treatment schedule, although two patients developed mild non-symptomatic hypertension. Serum ALT levels gradually decreased in all but one patient. The mean percentage decrease was 59.5% at the end of therapy (from 153 +/- 82 to 62 +/- 48 IU/L; P < 0.02). The ALT levels fell to the normal range in five patients, although once therapy was discontinued the enzyme levels tended to return to pretreatment levels. Serum aspartate aminotransferase and g-glutamyl transpeptidase levels similarly decreased. The serum HCV-RNA titre, determined by competitive RT-PCR, did not change in any patient throughout the study period. There were no appreciable alterations in other laboratory tests, such as serum creatinine levels and lymphocyte subsets, except for an increase in serum alkaline phosphatase levels. These findings suggest that CsA, even in a relatively low dose, reduces serum aminotransferase levels without serious side effects in patients with chronic hepatitis C, although an antiviral effect was not noted.

Hypervariable region sequence in cryoglobulin-associated hepatitis C virus in sera of patients with chronic hepatitis C: relationship to antibody response against hypervariable region genome.

Essential mixed cryoglobulinemia is frequently associated with hepatitis C virus (HCV) infection, with the formation of HCV antigen/antibody complexes. The hypervariable region (HVR) of the HCV E2/NS1 region is thought to include epitopes for neutralizing antibodies, but it remains uncertain whether cryoglobulins (CGs) contain such antibody-bound HCV. Thus, we studied HVR clones isolated from cryoprecipitate and supernatant in the sera of four chronic hepatitis C patients with cryoglobulinemia, and expressed as fusion proteins with glutathione S-transferase (GST). Patients' sera were tested for antibody binding to the proteins. The rate of anti-HVR antibody-positive clones was significantly higher in cryoprecipitate (89% +/- 13%, P < .05) than in supernatant (41% +/- 25%). Both HCV RNA and anti-HVR antibody were more concentrated in cryoprecipitates compared with those of serum and supernatant in two patients tested. Anti-HVR antibody-positive clones in cryoprecipitate showed common amino acid (aa) sequences in each of the four patients. Similarly, all the antibody-positive clones in supernatant showed the same aa sequences for three of the four patients. When aa sequences were compared with those of reported isolates with genotype 1b, the mean percentage of aa difference was greater in the clones from supernatant and in anti-HVR antibody-negative clones than in the clones from cryoprecipitate and in the antibody-positive clones, respectively. These findings indicate that serum CG contains anti-HVR antibody-bound HCV in patients with chronic hepatitis C. Anti-HVR antibody-free individual clones, which were more frequently noted in supernatant, showed closely related sequences, but which were of a heterogeneous quasispecies nature.

Sequence analysis of hypervariable region of hepatitis C virus (HCV) associated with immune complex in patients with chronic HCV infection.

Immune complex (IC) frequently exists in sera of patients with hepatitis C virus (HCV) infection. When circulating HCV particles are fractionated by differential flotation ultracentrifugation, HCV in the bottom fraction appears to be in the form of IC. Flotation ultracentrifugation of serum was done in 7 patients positive for serum anti-C3d-binding circulating IC and in 7 negative patients. In all IC-positive patients, HCV RNA was detected in the bottom fraction but not in the top fraction of 3 patients. Amino acid sequences of hypervariable region (HVR) of HCV in the bottom fraction of IC-positive patients were almost the same as those of whole serum, while those of the top fraction considerably differed from those of whole serum except for 1 case. These data suggest that the major population of HCV forms IC in IC-positive patients, and antibody response to the HVR of HCV is responsible for IC formation.

Deficiency of antibody response to hypervariable region of hepatitis C virus in patients with chronic hepatitis C.

BACKGROUND/AIMS: Frequent mutations in the hypervariable region of hepatitis C virus have been suggested to be a cause of persistent infection by providing a way for the virus to escape host immunity. However, the variation rate in the hypervariable region is often low in patients with chronic hepatitis. The aim of this study was to elucidate the mechanism of persistent infection in patients with chronic hepatitis by investigating the relationship between the antibody response to and the variation in hypervariable region. METHODS: The hypervariable regions of 26 clones of six patients with chronic hepatitis C were expressed as proteins fused with glutathione S-transferase, and sera of the patients were serially tested for antibody to these proteins. RESULTS: The extent of antibody response to the hypervariable region differed considerably among the patients. Three patients showed no or only scanty antibody response. These had a lower variation rate in the hypervariable region (0-1.3/year) than in the others with frequent or persistent antibody response (2.1-14.6/year). In two patients, serum samples were found to be reactive with the clones even before the appearance of the clones. In three patients, coexistence of the antibodies and corresponding clones were noted. An augmentation of antibody response always followed rises in serum alanine aminotransferase levels. CONCLUSION: Deficiency of antibody response to the hypervariable region may be one of the causes of persistency in hepatitis C virus infection.

Serial analysis of hepatitis B virus core nucleotide sequence of patients with acute exacerbation during chronic infection.

Recent studies suggest that hepatitis B virus (HBV) core region could be an immunological target and that amino acid (aa) substitutions are mostly restricted to a small segment located in the middle of the core region. We sequenced the middle portion of HBV core gene during the course of acute exacerbation of chronic hepatitis B, and compared aa variations between the region including ideal HLA-A2 binding motifs and the nonbinding region. Five HBeAg+ chronic hepatitis patients with subtype adr (three with HLA-A2 and two without HLA-A2) were selected and using polymerase chain reaction (PCR) and cloning system, the central part of core region (nt 2063 to 2365, 303 bp) was sequenced in sera from each patient at three time points; before, at the peak of, and after exacerbation of hepatitis. The second set of sera showed higher aa substitution rates in five and in three out of five patients compared with those of the first and third sera, respectively. No significant difference was found in the aa substitution rates for the region with ideal HLA-A2 binding motifs between patients with and without HLA-A2. In asymptomatic HBV carriers with persistently normal aminotransferase values, alterations of the aa sequence were not observed within the same time frame. The results suggest that aa substitutions often occur at some particular positions in the middle of HBV core region during acute exacerbation of the disease under possible host immune pressures. Furthermore, unidentified epitopes appear to exist in the central part of HBV core region and HLA-unrestricted lymphocytes may play a role in the immune response of chronic HBV carriers.

Serum HCV RNA titer at the end of interferon therapy predicts the long-term outcome of treatment.

BACKGROUND/AIMS: Serum HCV RNA was quantitated by the competitive polymerase chain reaction before, at the end of, and after interferon therapy. We assessed whether serum HCV RNA titer at the end of interferon therapy predicts the long-term outcome of treatment. METHODS/RESULTS: Of 71 patients treated with various doses of interferons, 21 became negative for HCV RNA persistently during follow up of 2 years, and they were considered as complete responders. The serial determinations of HCV RNA titer for each individual showed that in patients with HCV RNA negative at the end of therapy, the complete response rate was quite high (78.6%), while in patients with HCV RNA titer > or = 10(4) copies/ml at the end of therapy, none became complete responders in long-term follow up. The percentage decreasing to < or = 10(2) copies/ml of HCV RNA at termination of interferon tended to be higher in patients with genotype 2a (14/21, 66.7%) than in those with genotype 1b (18/42, 42.9%). The complete response rate of patients whose viral load was < or = 10(2) copies/ml at termination of interferon was significantly higher in genotype 2a (11/14, 78.6%) than in genotype 1b (5/18, 27.8%) (p < 0.01). Pretreatment HCV RNA titer appeared to correlate to the titer at the end of therapy (r = 0.596, p < 0.001); even when HCV RNA decreased to < or = 10(2) copies/ml, the higher pretreatment titer indicated a lower likelihood of complete response (p < 0.05). CONCLUSIONS: These results indicate that HCV genotype and pretreatment viral titer are important factors in the response to interferon therapy. In addition, our study suggests that it is possible to stop interferon therapy at an appropriate time by monitoring HCV RNA titer.

Serum cryoglobulin and chronic hepatitis C virus disease among Japanese patients.

OBJECTIVES: Hepatitis C virus (HCV)-associated mixed cryoglobulins appear to be detected often in hepatitis C-related chronic liver disease. The association of the two phenomenon among Japanese patients is the subject of the present study. METHODS: Serum levels of total hemolytic complement (CH50) and anti-C3d-binding immune complex, as well as the prevalence of cryoglobulins, were studied in 213 patients with chronic liver disease (hepatitis C, 155; hepatitis B, 58). Cryoprecipitates were tested for anti-HCV Ab and HCV RNA. RESULTS: CH50 activity was significantly lower in patients with hepatitis C than in those with hepatitis B except in responders to interferon who showed a sustained loss of HCV RNA. Cryoglobulins were detected in 24 (37%) of 65 patients with hepatitis C; they generally consisted of polyclonal immunoglobulins but one case. Cryoglobulins were more frequently observed in cirrhotic patients and in those with a longer duration of disease. Cryoglobulinemia-related clinical signs such as vasculitis occurred in only three cases. Patients with cryoglobulins had lower CH50 activity and higher immune complex values than those without cryoglobulins. Anti-HCV Ab and HCV RNA were detected in all cryoprecipitates tested. CONCLUSIONS: These findings suggest that HCV is a major cause of cryoglobulins and advanced liver damage. However, serum cryoglobulins with polyclonal immunoglobulins appear to be less frequent among Japanese patients than among those studied in Western countries.

Predictive factors in the response to interferon therapy in chronic hepatitis C.

Factors predicting the efficacy of interferon therapy were statistically analyzed on 111 patients with chronic hepatitis C. Of the treated patients (total doses of interferon; 96-468 MU), 35 (31.5%) had a long-term remission. On multivariate analysis, hepatitis C virus genotype (p < 0.0001), histological diagnosis (p < 0.05), fibrosis score of histological activity index (p < 0.01) and source of infection (p < 0.05) were found useful for predicting the response to interferon therapy. Our findings suggest that the outcome of interferon therapy can be predicted to some degree from pretreatment data, and that a new therapeutic strategy is necessary for the group of patients who are predicted to be nonresponders.

Changes in serum hepatitis C virus RNA titer and response to interferon therapy in patients with chronic hepatitis C.

Response to interferon (IFN) therapy for chronic hepatitis C has been determined by the alteration of serum alanine aminotransferase (ALT) values. However, eradication of hepatitis C virus (HCV) could be another aim of the therapy. Thus, we serially measured serum HCV RNA levels during therapy and for at least 12 months after cessation of therapy in 65 patients with chronic hepatitis C who received IFN-alpha (49 cases) or -beta (16 cases). The presence of HCV and its amount were measured by the combination of nested and competitive PCR. Twenty-seven patients, who were categorized as complete responders, showed sustained normalization of ALT values for more than six months posttreatment. The viral RNA titers at pretreatment were significantly lower in complete responders (logarithmic copy numbers/ml: 5.4 +/- 1.3, P < 0.001) than in partial and nonresponders. Complete response rate was significantly higher in patients with HCV genotype III (68.4%, P < 0.01) than those with type II (23.6%). Among 27 complete responders, HCV RNA became undetectable in only 13 patients six months after completion of therapy, and 11 still had low levels of viremia; however, none experienced relapse of the disease during follow-up of 12-24 months. Three complete responders showed lasting high-titered viremia, and their ALT values rose again during follow-up. Our data suggest that IFN treatment of chronic hepatitis C is often ineffective in eradicating HCV infection even in responders, and long-term follow-up study is necessary to determine the sustained beneficial effect of IFN.