Autoimmunity and glomerulonephritis in mice with targeted deletion of the serum amyloid P component gene: SAP deficiency or strain combination?

Human serum amyloid P component (SAP) binds avidly to DNA, chromatin and apoptotic cells in vitro and in vivo. 129/Sv x C57BL/6 mice with targeted deletion of the SAP gene spontaneously develop antinuclear autoantibodies and immune complex glomerulonephritis. SAP-deficient animals, created by backcrossing the 129/Sv SAP gene deletion into pure line C57BL/6 mice and studied here for the first time, also spontaneously developed broad spectrum antinuclear autoimmunity and proliferative immune complex glomerulonephritis but without proteinuria, renal failure, or increased morbidity or mortality. Mice hemizygous for the SAP gene deletion had an intermediate autoimmune phenotype. Injected apoptotic cells and isolated chromatin were more immunogenic in SAP(-/-) mice than in wild-type mice. In contrast, SAP-deficient pure line 129/Sv mice did not produce significant autoantibodies either spontaneously or when immunized with extrinsic chromatin or apoptotic cells, indicating that loss of tolerance is markedly strain dependent. However, SAP deficiency in C57BL/6 mice only marginally affected plasma clearance of exogenous chromatin and had no effect on distribution of exogenous nucleosomes between the liver and kidneys, which were the only tissue sites of catabolism. Furthermore, transgenic expression of human SAP in the C57BL/6 SAP knockout mice did not abrogate the autoimmune phenotype. This may reflect the different binding affinities of mouse and human SAP for nuclear autoantigens and/or the heterologous nature of transgenic human SAP in the mouse. Alternatively, the autoimmunity may be independent of SAP deficiency and caused by expression of 129/Sv chromosome 1 genes in the C57BL/6 background.     

Exploiting T cell receptor genes for cancer immunotherapy

Adoptive antigen-specific immunotherapy is an attractive concept for the treatment of cancer because it does not require immunocompetence of patients, and the specificity of transferred lymphocytes can be targeted against tumour-associated antigens that are poorly immunogenic and thus fail to effectively trigger autologous T cell responses. As the isolation and in vitro expansion of antigen-specific lymphocytes is difficult, 'conventional' adoptive T cell therapy can only be carried out in specialized centres in small numbers of patients. However, T cell receptor (TCR) genes isolated from antigen-specific T cells can be exploited as generic therapeutic molecules for 'unconventional' antigen-specific immunotherapy. Retroviral TCR gene transfer into patient T cells can readily produce populations of antigen-specific lymphocytes after a single round of polyclonal T cell stimulation. TCR gene modified lymphocytes are functionally competent in vitro, and can have therapeutic efficacy in murine models in vivo. TCR gene expression is stable and modified lymphocytes can develop into memory T cells. Introduction of TCR genes into CD8(+) and CD4(+) lymphocytes provides an opportunity to use the same TCR specificity to produce antigen-specific killer and helper T lymphocytes. Thus, TCR gene therapy provides an attractive strategy to develop antigen-specific immunotherapy with autologous lymphocytes as a generic treatment option.     

Racial differences in acceptability and availability of drugs and early initiation of substance use

This paper examines differences among three racial groups in exposure to three risk factors for drug use (availability of drugs, acceptability of drug use, and peer alcohol use), and the relationship of these factors to drug use initiation in a sample of preadolescent urban youths. Tobacco and alcohol initiation rates were highest among Whites, lower among Blacks, and lowest among Asian-Americans. Paralleling these differences, White youths reported the greatest access to marijuana, greatest parental tolerance of substance use, and greatest intentions to use drugs as adults. Blacks somewhat less, and Asian-Americans the least. No racial differences appear in the proportion who reported that their peers used alcohol. Marijuana availability and peer use predicted substance initiation for all three racial groups. However, intentions to use substances as an adult and perceived parental tolerance of substance use predicted drug use only for White and Asian-American youths, while the expectation of punishment for drug use predicted lower drug use only among Black youths. Implications for prevention are discussed.     

Redefining the R1 resection for pancreatic ductal adenocarcinoma: tumour lymph nodal burden and lymph node ratio are the only prognostic factors associated with survival

Introduction: The presence of positive nodal disease (LND) and the number of lymph nodes involved (LNB) are known to be significant prognostic markers for resected adenocarcinoma of the pancreas. In addition, the ratio of the number of involved nodes to the number of nodes resected known as the lymph node ratio (LNR) is emerging as an important prognostic marker. The role of the resection margin (RM) as presently defined (R1 ≤ 1 mm) is unclear as results differ based on the dataset. The aim of this study was to assess the impact of nodal disease and a redefined RM on outcome.Material and methods: Retrospective analysis of pancreatic head resections for adenocarcinomas from 2003–2009. The RM was re-analysed based on tumour clearance and categorized into: histopathological evidence of a tumour; ≤0.5 mm, ≤1 mm, ≤1.5 mm, or ≤2.0 mm of the actual surgical resection margin. The impact of histopathological variables on cancer-specific survival (CSS) and disease-free survival (DFS) was analysed.Results: LND, LNB and LNR were independent prognostic markers for CSS (P = 0.048, 0.003, 0.016) but, did not influence DFS. A LNR < 0.143 was associated with a higher CSS [38.16 ± 4.69 versus 20.59 ± 2.20 months, P = 0.0042, hazard ratio (HR) 3.74 (95% confidence interval (CI) 1.52–9.23)]. An R1 RM was not associated with CSS or DFS on multivariate analysis, irrespective of the distance. LNB and LNR maintained independent significance irrespective of the size of the RM.Conclusion: LNB and LNR are the only prognostic factors for CSS in patients with pancreatic head adenocarcinoma, but do not predict recurrence. Microscopic RMs does not seem to influence the outcome even when redefined. Further prospective studies are indicated to substantiate these findings.     

Bleeding symptoms and coagulation abnormalities in 337 patients with AL-amyloidosis

Haemorrhage is a frequent manifestation of amyloidosis. We performed a retrospective clinical analysis of 337 patients with systemic immunoglobulin light-chain (AL)-amyloidosis, in whom whole-body serum amyloid P component (SAP) scintigraphy and a clotting screen had been performed. Abnormal bleeding was noted in 94 cases (28%), and the coagulation screen was abnormal in 172 cases (51%). The most common abnormalities were prolongation of the thrombin time (TT; 108 cases, 32%) and the prothrombin time (PT; 82 cases, 24%). In multivariate analysis, a prolonged PT was the only coagulation abnormality associated with abnormal bleeding (P = 0.0012), but this was independent of the whole-body amyloid load. Prolongation of the TT was associated with hepatic amyloid infiltration (P < 0.00001), with proteinuria (P < 0.001) and low serum albumin (P < 0.00001). In 154 patients who were studied further, subnormal factor X activity (FX:C) was found in 22 cases (14%). In cases with subnormal FX:C, the corresponding factor X antigen (FX:Ag) measurements were consistently higher (median FX:Ag/FX:C 2.5, range 0.81-9.25, n = 16) than cases with normal FX:C (median FX:Ag/FX:C 0.96, range 0.65-1.29, n = 28, P < 0.0001). No evidence was found of an FX inhibitor. Of the 48/154 (31%) cases with a prolonged TT, the reptilase time was also prolonged in 38/48 cases (79%). These data show that haemorrhage and abnormal coagulation are common in AL-amyloidosis and are multifactorial in origin. We provide evidence suggesting that hepatic amyloid infiltration and nephrotic syndrome are determinants of the TT. In most patients, prolongation of the PT was explained by reduction in FX:C, but this was not wholly explained by a reduction in FX:Ag.     

Renal transplantation for amyloid end-stage renal failure-insights from serial serum amyloid P component scintigraphy

Although end-stage renal failure (ESRF) is common in systemic amyloidosis, few such patients receive renal transplants. Serum amyloid P component (SAP) scintigraphy is a specific method for the imaging and quantification of amyloid deposits in vivo, which has not previously been used to evaluate the outcome of renal transplantation in patients with amyloidosis. Evidence of renal graft amyloid was sought by SAP scintigraphy in 15 patients with systemic amyloidosis who had undergone renal transplantation 42-216 months (median, 73 months) previously. Prospective serial scans were obtained annually in eight cases. Renal grafts studied shortly after transplantation gave blood-pool images. The grafts remained normal in all patients whose underlying amyloidogenic disorder had remitted, whereas there was abnormal uptake of labelled SAP, indicating graft amyloidosis, in four out of 10 patients whose amyloid fibril precursor protein supply had not diminished. Graft amyloidosis was corroborated by renal dysfunction in each case, and by histology in one patient. SAP scintigraphy enables renal transplant grafts to be monitored noninvasively for involvement by amyloid. The lack of graft amyloidosis in all patients in whom the amyloidogenic underlying disorder had remitted, and in more than half of those in whom it had not, supports the use of renal transplantation for ESRF in systemic amyloidosis.     

Experimental mandibular osteomyelitis: Therapeutic trials with hyperbaric oxygen

Hyperbaric oxygen (HBO) has been reported to be beneficial in the treatment of mandibular osteomyelitis; however, controlled laboratory studies have been limited to the long bones. In this study, osteomyelitis was created in surgically fractured rabbit mandibles by inoculation of Bacteroides melaninogenicus. Two months after inoculation, osteomyelitis was verified by bacterial cultures and inspection of the fracture sites. The animals were then randomly divided into treatment and control groups. The treatment group received HBO (2 atmospheres) for two hours daily for 40 treatment days, whereas the control group was maintained on ambient air. Although HBO therapy did not eliminate the chronic osteomyelitis, it did result in a significant improvement in sinus tract healing, osseous repair, and diminished mobility at the fracture site.     

Routine terminations of pregnancy--should we screen for gestational trophoblastic neoplasia?

After termination of pregnancy for non-medical reasons, the products of conception are often not routinely examined for gestational trophoblastic neoplasia. Between 1995 and 2001 we identified 15 women without and 36 women with a pathological diagnosis of gestational trophoblastic neoplasia at the time of their pregnancy termination. Women without a diagnosis were significantly more likely to have subsequent life-threatening complications of gestational trophoblastic neoplasia (four of 15 vs none of 36; p=0.003), and to require surgical intervention (15 of 15 vs one of 36; p<0.0001) and chemotherapy (nine of 15 vs two of 36; p<0.0001). All women should be screened for gestational trophoblastic neoplasia after termination of pregnancy.