Hydrogel-Based Matrix-Associated Autologous Chondrocyte Implantation Shows Greater Substantial Clinical Benefit at 24 Months Follow-Up than Microfracture: A Propensity Score Matched-Pair Analysis

OBJECTIVE

To compare substantial clinical benefit (SCB) of a hydrogel-based, matrix-associated autologous chondrocyte implantation (M-ACI) method versus microfracture (MFx) in the treatment of knee cartilage defects.

DESIGN

Propensity score matched-pair analysis, using the MFx control group of a phase III study as comparator for M-ACI treatment in a single-arm phase III study, resulting in 144 patients in the matched-pair set.

RESULTS

Groups were comparable regarding baseline Knee Injury and Osteoarthritis Outcome Score (KOOS), sex, age, body mass index, symptom duration, smoking status, and previous knee surgeries. Defect sizes in the M-ACI group were significantly larger than in the MFx group (6.4 cm2 vs. 3.7 cm2). Other differences concerned location, number, and etiology of defects that were not considered to influence the interpretation of results. At 24 months, significantly more patients in the M-ACI group achieved SCB in KOOS pain (72.2% vs. 48.6%; P = 0.0108), symptoms (84.7% vs. 61.1%, P = 0.0039), sports/recreation (84.7% vs. 56.9%, P = 0.0008), and quality of life (QoL; 72.2% vs. 44.4%, P = 0.0014). The SCBs for KOOS activities in daily living and International Knee Documentation Committee score were higher for M-ACI but not significantly different from MFx. The SCB rates consistently favored M-ACI from 3 months onward. The highest improvements from baseline at 24 months in patients with SCB were observed for KOOS sports/rec. (M-ACI: 60.8 points, MFx: 55.9 points) and QoL (M-ACI: 58.1, MFx: 57.4).

CONCLUSION

Hydrogel-based M-ACI demonstrated superior SCB in KOOS pain, symptoms, sports/rec., and QoL compared with MFx in patients with knee cartilage defects through 2 years follow-up.

Comparison of Hydrogel-Based Autologous Chondrocyte Implantation Versus Microfracture: A Propensity Score Matched-Pair Analysis

Background

Few studies exist for large defects comparing matrix-associated autologous chondrocyte implantation (M-ACI) with other cartilage repair methods due to the limited availability of suitable comparator treatments.

Purpose

To compare the clinical efficacy of a novel hydrogel-based M-ACI method (NOVOCART Inject plus) versus microfracture (MFx) in patients with knee cartilage defects.

Study Design

Cohort study; Level of evidence, 3.

Methods

Propensity score matched-pair analysis was used to compare the 24-month outcomes between the M-ACI treatment group from a previous single-arm phase 3 study and the MFx control group from another phase 3 study. Patients were matched based on preoperative Knee injury and Osteoarthritis Outcomes Score (KOOS), symptom duration, previous knee surgeries, age, and sex, resulting in 144 patients in the matched-pair set (72 patients per group). The primary endpoint was the change in least-squares means (ΔLSmeans) for the KOOS from baseline to the 24-month assessment.

Results

Defect sizes in the M-ACI group were significantly larger than in the MFx group (6.4 versus 3.7 cm2). Other differences included defect location (no patellar or tibial defects in the MFx group), number of defects (33.3% with 2 defects in the M-ACI group versus 9.7% in the MFx group), and defect cause (more patients with degenerative lesions in the M-ACI group). The M-ACI group had higher posttreatment KOOS (M-ACI versus MFX: 81.8 ± 16.8 versus 73.0 ± 20.6 points) and KOOS ΔLSmeans from baseline to 24 months posttreatment (M-ACI versus MFX: 36.9 versus 26.9 points). Treatment contrasts in KOOS ΔLSmeans from baseline indicated statistical significance in favor of M-ACI from 3 to 24 months posttreatment (P = .0026). Significant and clinically meaningful differences in favor of M-ACI at 24 months were also found regarding International Knee Documentation Committee (IKDC) score ΔLSmeans from baseline (37.8 versus 30.4 points; P = .0334), KOOS responder rates at 24 months (≥10-point improvement from baseline; 94.4% versus 65.3%; P < .0001), IKDC responder rates at 24 months (>20.5-point improvement from baseline; 83.3% versus 61.1%, P = .0126) and MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score in a subgroup of patients (LS means, 86.9 versus 69.1; P = .0096).

Conclusion

In this exploratory analysis, M-ACI using an in situ crosslinked hydrogel demonstrated superior clinical and structural (MOCART) 24-month outcomes compared with MFx in patients with knee cartilage defects.

Adjacent cartilage tissue structure after successful transplantation: a quantitative MRI study using T2 mapping and texture analysis

OBJECTIVES

The aim of this study was to assess the texture of repair tissue and tissue adjacent to the repair site after matrix-associated chondrocyte transplantation (MACT) of the knee using gray-level co-occurrence matrix (GLCM) texture analysis of T₂ quantitative maps.

METHODS

Twenty patients derived from the MRI sub-study of multicenter, single-arm phase III study underwent examination on a 3 T MR scanner, including a T₂ mapping sequence 12 and 24 months after MACT. Changes between the time points in mean T₂ values and 20 GLCM features were assessed for repair tissue, adjacent tissue, and reference cartilage. Differences in T₂ values and selected GLCM features between the three cartilage sites at two time points were analyzed using linear mixed-effect models.

RESULTS

A significant decrease in T₂ values after MACT, between time points, was observed only in repair cartilage (p < 0.001). Models showed significant differences in GLCM features between repair tissue and reference cartilage, namely, autocorrelation (p < 0.001), correlation (p = 0.015), homogeneity (p = 0.002), contrast (p < 0.001), and difference entropy (p = 0.047). The effect of time was significant in a majority of models with regard to GLCM features (except autocorrelation) (p ≤ 0.001). Values in repair and adjacent tissue became similar to reference tissue over time.

CONCLUSIONS

GLCM is a useful add-on to T₂ mapping in the evaluation of knee cartilage after MACT by increasing the sensitivity to changes in cartilage structure. The results suggest that cartilage tissue adjacent to the repair site heals along with the cartilage implant.

KEY POINTS

• GLCM is a useful add-on to T₂ mapping in the evaluation of knee cartilage after MACT by increasing the sensitivity to changes in cartilage structure. • Repair and adjacent tissue became similar to reference tissue over time. • The results suggest that cartilage tissue adjacent to the repair site heals along with the cartilage implant.

Treatment of Large Cartilage Defects in the Knee by Hydrogel-Based Autologous Chondrocyte Implantation: Two-Year Results of a Prospective, Multicenter, Single-Arm Phase III Trial

OBJECTIVE

To evaluate the clinical outcome of a hydrogel-based autologous chondrocyte implantation (ACI) for large articular cartilage defects in the knee joint.

DESIGN

Prospective, multicenter, single-arm, phase III clinical trial. ACI was performed in 100 patients with focal full-thickness cartilage defects ranging from 4 to 12 cm² in size. The primary outcome measure was the responder rate at 2 years using the Knee Injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Two years after ACI treatment, 93% of patients were KOOS responders having improved by ≥10 points compared with their pre-operative level. The primary endpoint of the study was met and demonstrated that the KOOS response rate is markedly greater than 40% with a lower 95% CI (confidence interval) of 86.1, more than twice the pre-specified no-effect level. KOOS improvement (least squares mean) was 42.0 ± 1.8 points (95% CI between 38.4 and 45.7). Mean changes from baseline were significant in the overall KOOS and in all 5 KOOS subscores from Month 3 (first measurement) to Month 24 (inclusive) (P < 0.0001). The mean MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score after 24 months reached 80.0 points (95% CI: 70.0-90.0 points) and 92.1 points in lesions ≤ 5 cm².

CONCLUSIONS

Overall, hydrogel-based ACI proved to be a valuable treatment option for patients with large cartilage defects in the knee as demonstrated by early, statistically significant, and clinically meaningful improvement up to 2 years follow-up. Parallel to the clinical improvements, MRI analyses suggested increasing maturation, re-organization, and integration of the repair tissue.

TRIAL REGISTRATION

NCT03319797; EudraCT No.: 2016-002817-22.

Differentiation of Cartilage Repair Techniques Using Texture Analysis from T2 Maps

OBJECTIVE

The aim of this study was to investigate texture features from T2 maps as a marker for distinguishing the maturation of repair tissue after 2 different cartilage repair procedures.

DESIGN

Seventy-nine patients, after either microfracture (MFX) or matrix-associated chondrocyte transplantation (MACT), were examined on a 3-T magnetic resonance (MR) scanner with morphological and quantitative (T2 mapping) MR sequences 2 years after surgery. Twenty-one texture features from a gray-level co-occurrence matrix (GLCM) were extracted. The texture feature difference between 2 repair types was assessed individually for the femoral condyle and trochlea/anterior condyle using linear regression models. The stability and reproducibility of texture features for focal cartilage were calculated using intra-observer variability and area under curve from receiver operating characteristics.

RESULTS

There was no statistical significance found between MFX and MACT for T2 values (P = 0.96). There was, however, found a statistical significance between MFX and MACT in femoral condyle in GLCM features autocorrelation (P < 0.001), sum of squares (P = 0.023), sum average (P = 0.005), sum variance (P = 0.0048), and sum entropy (P = 0.05); and in anterior condyle/trochlea homogeneity (P = 0.02) and dissimilarity (P < 0.001).

CONCLUSION

Texture analysis using GLCM provides a useful extension to T2 mapping for the characterization of cartilage repair tissue by increasing its sensitivity to tissue structure. Some texture features were able to distinguish between repair tissue after different cartilage repair procedures, as repair tissue texture (and hence, probably collagen organization) 24 months after MACT more closely resembled healthy cartilage than did MFX repair tissue.

IMA901: a multi-peptide cancer vaccine for treatment of renal cell cancer

Despite a major improvement in the treatment of advanced kidney cancer by the recent introduction of targeted agents such as multi-kinase inhibitors, long-term benefits are still limited and a significant unmet medical need remains for this disease. Cancer immunotherapy has shown its potential by the induction of long-lasting responses in a small subset of patients, however, the unspecific immune interventions with (high dose) cytokines used so far are associated with significant side effects. Specific cancer immunotherapy may circumvent these problems by attacking tumor cells while sparing normal tissue with the use of multi-peptide vaccination being one of the most promising strategies. We here summarize the clinical and translational data from phase I and II trials investigating IMA901. Significant associations of clinical benefit with detectable T cell responses against the IMA901 peptides and encouraging survival data in treated patients has prompted the start of a randomized, controlled phase III trial in 1st line advanced RCC with survival results expected toward the end of 2015. Potential combination strategies with the recently discovered so-called checkpoint inhibitors are also discussed.

Abstract SY27-03: Biomarker-guided development of novel multi-peptide cancer vaccines - from discovery to phase lll trials

Translational research and the clinical development of therapeutic cancer vaccines require strong scientific rationale in order to better understand the mode-of-action and to incorporate the lessons learned in the optimization of cancer vaccines by (i) selecting appropriate immunomodulators to generate more effective vaccine regimens, (ii) combining vaccine regimens and standard-of-care therapeutics with synergistic potential and (iii) identifying patient populations that may have a better chance of responding to the vaccine.

Here we demonstrate how preclinical and clinical immune response markers combined with cellular and serum biomarkers that define the immune regulatory environment were utilized as guiding tools in the development of three novel multi-peptide vaccines in renal cell cancer (IMA901), colorectal cancer (IMA910) and glioblastoma (IMA950).

All three vaccine products comprise multiple tumor-associated peptides (TUMAPs) confirmed, by mass spectrometry, to be naturally presented in human cancer tissue. Each vaccine was selected using differential transcriptomics approaches and validated by in vitro analysis of immunogenicity with artificial antigen-presenting cells followed by in vivo analysis of immune responses in clinical trials. The vaccines contain HLA class I and II-restricted peptides designed to elicit CD8+ cytotoxic and CD4+ helper T-cell responses, respectively.

IMA901 is a novel renal cell cancer (RCC) vaccine consisting of 9 HLA class I and 1 HLA class II TUMAPs with the majority of peptides confirmed to be naturally presented on and shared between RCC tissues. Consecutive independent Phase I and II clinical studies were conducted in HLA-A*02+ advanced/metastatic RCC patients (total 96) receiving repeated intradermal vaccinations with IMA901 plus human granulocyte-macrophage colony-stimulating factor (GM-CSF). The two studies demonstrated an association between overall survival and multiple vaccine-induced T-cell responses and an impact of single-dose cyclophosphamide (300 mg/m2) on regulatory T cells (Tregs) and overall survival. Furthermore, two myeloid-derived suppressor cell (MDSC) populations (CD14+ HLA-DR−/low and CD14− CD11b+ CD15+) were significantly negatively associated with survival in vaccinated RCC patients.

The knowledge acquired in these trials was used to design a randomized, controlled Phase III study. Recruitment of 339 advanced/metastatic first-line RCC patients was recently completed. IMA901 is combined with the tyrosine kinase inhibitor sunitinib based on the findings that sunitinib down-modulates the two MDSC populations described above. Furthermore, in this Phase III study, the relevance of two serum biomarkers (Apoliprotein A1 and CCL17) found in the Phase II study to be associated with immune response and OS will be prospectively explored (Walter, Weinschenk et al., Nat Med 2012).

IMA910 is a novel colorectal cancer (CRC) vaccine consisting of 10 HLA class I and 3 HLA class II TUMAPs with the majority of peptides confirmed to be naturally presented on and shared between CRC tissues. A Phase I/II trial was conducted in 92 HLA-A*02+ advanced colorectal cancer patients with stable (SD) or responding (PR/CR) disease after 12 weeks of first-line oxaliplatin-based therapy. Thereafter, first-line oxaliplatin-based chemotherapy was stopped and patients received a single dose of cyclophosphamide to reduce Tregs followed by repeated intradermal vaccinations with IMA910 plus GM-CSF (first cohort; n=66) with or without topically applied imiquimod (second cohort; n=26). IMA910 elicited immune responses towards multiple class I (in 43% of the subjects) and class II TUMAPs (65%). Similarly to the IMA901 vaccine trial in RCC, such vaccine-induced CD8+ as well as CD4+ T-cell responses to multiple TUMAPs were associated with increased overall survival. Patients who additionally received imiquimod were more often multi-peptide class I responders (p=0.016) as determined by intracellular cytokine staining (ICS) assay and showed a modestly (two-fold) increase of T-cell freqencies (p=0.12) as determined by HLA multimer assay. Interestingly, the same two populations of MDSC as described above in renal cell cancer patients were negatively associated with vaccine-induced immune response and overall survival implying a potential generalized role of these two MDSC populations. Further development of this vaccine is planned in a setting where an MDSC-modulating standard-of-care (e.g. chemotherapy) is applied.

IMA950 is a novel glioblastoma vaccine consisting of 9 HLA class I and 2 HLA class II TUMAPs with the majority of peptides confirmed to be naturally presented on and shared between glioblastoma tissues. A Phase I study sponsored by Cancer Research UK is currently ongoing in the United Kingdom. A total of 45 newly diagnosed glioblastoma patients will be treated. The study is expected to complete recruitment in the first quarter of 2013. The primary objectives of this first-in-man study are to assess the safety, tolerability and immunogenicity of IMA950 plus GM-CSF when given alongside standard chemoradiotherapy followed by adjuvant chemotherapy with temozolomide. Patients enter the trial into one of two cohorts (start of vaccination either prior to or after initial chemoradiotherapy) in order to determine potential differences in the immune response in these two cohorts. First immunomonitoring data indicate a high immune as well as multi-TUMAP response rate in the study population. Updated and unpublished immune data will be presented at the meeting.

Analysis of the in vitro immunogenicity data obtained from healthy donors during the discovery phases of these programs and comparison of these data with the in vivo immunogenicity data obtained in the clinical trials demonstrated that in all four clinical trials in a total of approx. 200 patients the in vitro data correlated with the in vivo data. This implies that such a standardized in vitro assay system may be utilized in future to further optimize vaccine regimens by selecting the most immunogenic novel peptides before entering clinical trials.

In conclusion, we suggest that use of preclinically well characterized naturally presented tumor antigens combined with systematic clinical immunomonitoring and cellular/serum biomarker screening will be helpful to guide rational development of novel cancer vaccines.

Citation Format: Harpreet Singh-Jasuja, Steffen Walter, Toni Weinschenk, Alexandra Kirner, Andrea Mayer-Mokler, Norbert Hilf, Oliver Schoor, Pierre-Yves Dietrich, James Richtie, Roy Rampling, Frank Mayer, Arnulf Stenzl, Brian Rini, Carsten Reinhardt, Hans-Georg Rammensee. Biomarker-guided development of novel multi-peptide cancer vaccines - from discovery to phase lll trials. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr SY27-03. doi:10.1158/1538-7445.AM2013-SY27-03

Abstract 5365: Prolonged survival of patients with advanced renal cancer responding to multi-peptide vaccine IMA901 after single-dose cyclophosphamide

Translational research and the clinical development of therapeutic cancer vaccines requires stronger scientific rationalization. Here we demonstrate how immune response markers as well as biomarkers defining the immune regulatory environment were utilized as guiding tools from discovery to advanced clinical trials of IMA901, a novel therapeutic vaccine for the treatment of renal cell carcinoma (RCC). IMA901 consists of multiple tumor-associated peptides (TUMAPs) confirmed to be naturally presented in human RCC tissue by mass spectrometry, selected using differential transcriptomics and preclinically validated by systematic analysis of immunogenicity with artificial antigen-presenting cells. Two consecutive independent clinical studies in a total of 96 HLA-A*02+ advanced/metastatic RCC patients were conducted. The phase I study revealed that T-cell responses to multiple IMA901 antigens were significantly associated with disease control and negatively associated with the presence of FoxP3+ regulatory T cells (Tregs). The subsequent randomized phase II study demonstrated that pre-treatment with a single low dose of cyclophosphamide (Cy) reduced Treg frequencies and prolonged overall survival (OS) in patients who mounted an immune response to the IMA901 vaccine. Additionally, T-cell responses to multiple IMA901 antigens were again associated with clinical benefit. Furthermore, a comprehensive prognostic and predictive biomarker program was conducted. Among cellular biomarkers, highly significantly elevated levels of myeloid-derived suppressor cells (MDSC), IL-17-/IL-10-secreting T cells and dysfunctional T cells in RCC patients vs. healthy individuals were found. Two MDSC populations (CD14+ HLA-DR- and CD14- CD11b+ CD15+) were significantly negatively associated with survival in vaccinated RCC patients. Interestingly, both MDSC populations were also found to be negatively associated with OS in an independent trial in colorectal cancer patients (N=79) implying a broader role for these MDSC species. Additionally, among over 300 serum biomarkers tested, apolipoprotein A-I (ApoA1) and the chemokine CCL17 were found to be predictive for both immune responses to IMA901 and survival of the RCC patients. The knowledge acquired in these trials was used to design a randomized phase III study. In this ongoing study, IMA901 is combined with the tyrosine kinase inhibitor sunitinib based on the findings that sunitinib downmodulates the two MDSC populations described above. Furthermore, in this phase III study, the relevance of ApoA1/CCL17 will be explored by prospectively defined subgroup analyses.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5365. doi:1538-7445.AM2012-5365

Abstract 302: Multiple distinct populations of myeloid derived suppressor cells in IMA901 treated renal cell cancer patients correlate with survival and with T-cell dysfunctions

IMA901 is a therapeutic cancer vaccine for the treatment of renal cell cancer patients based on the selection of naturally presented tumor-associated peptides. A previous phase I study (N=28 patients) showed significant correlations of clinical benefit with T-cell responses to multiple IMA901 peptides. Based on this experience, a randomized phase II study was designed to explore the biological and clinical efficacy of IMA901. Different regulatory cell populations were assessed in patients prior to vaccination, including 6 phenotypically defined populations of myeloid derived suppressor cells (MDSCs).

A total of 68 HLA-A*02-positive RCC patients with documented progression during or after first-line therapy with cytokines or TKI were randomized to receive or not a single infusion of low-dose cyclophosphamide (CY; 300 mg/m2) three days prior to start repeated i.d. vaccinations with IMA901 in association with 75 µg GM-CSF i.d. Among them, 64 pts were eligible according to the pre-specified, per-protocol analysis. Patients receiving a single infusion of CY had a significant decrease of FoxP3-positive regulatory T cells (Tregs) after 3 days (p=0.014), particularly in Ki67+ (proliferating) Tregs (p=0.006). Patients receiving low-dose CY also showed a trend for improved overall survival (OS) as compared to the non-CY group (OS not reached after 25 months of follow-up vs. 16 months, respectively; p=0.086). Marginally significantly better OS rates were seen in immune responders compared to non-responders in the overall population (p=0.048), but highly significantly so in the subgroup of patients randomized to CY (p=0.006).

6 previously reported MDSC populations were analyzed from cryopreserved PBMCs by a single multi-color flow cytometry staining panel. A high overlap (&gt;25%) was found for only 2 MDSC populations, so 6 populations represented five distinct MDSC subtypes. MDSC levels were significantly increased in patient samples as compared to matched healthy donors (p&lt;0.0001 to p=0.0043). Interestingly, two populations designated MDSC4 (CD14+ HLA-DR-) and MDSC5 (CD14- CD11b+ CD15+) were negatively correlated with survival (p=0.033 and p=0.005) in the patients of this trial prior to immunotherapy intervention. Analysis of dysfunctionality of T cells characterized by decreased levels of TCR zeta chain expression revealed that patients had lower levels of TCR zeta chain expression than matched healthy donors (p&lt;0.0001) and that low levels of TCR zeta chain were correlated with high levels of 4 MDSC phenotypes (p&lt;0.0001 to p=0.04), suggesting that MDSC levels are linked to the suppression of T cells in RCC patients.

To our knowledge, this is the first study assessing the impact of MDSC levels on the survival of cancer patients by employing a novel method that can differentiate five distinct MDSC populations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 302. doi:10.1158/1538-7445.AM2011-302

Concanavalin A application to the olfactory epithelium reveals different sensory neuron populations for the odour pair D- and L-carvone

Carvone enantiomers (D and L optical isomers) have been shown to be discriminable by humans even though the odor qualities are quite similar. Our experiment is based on a finding (J. Steroid Biochem. Molec. Biol. 1991;39(4B):621) that Concanavalin A (ConA) applied to a frog olfactory epithelium preparation blocks cAMP transduction induced by D- but not by L-carvone. We used standard operant conditioning methods to train animals to discriminate low odor concentrations of D-carvone from clean air, to discriminate L-carvone from clean air; or to discriminate between clean air and the odors of D-carvone, L-carvone, ethyl acetate and methacrylic acid. After perfusion of the nasal cavity with ConA, rats did not respond to D-carvone above or near chance level, while the L-carvone response was not affected at the same or higher ConA doses. However, for rats trained on both enantiomers and the two other unrelated odorants, the D-carvone response remained unaffected by ConA. These results suggest to us that: (1) ConA blocks at least one chiral receptor selective for D-carvone; (2) D-carvone odor quality is modified by ConA so that it is no longer recognized by rats trained on D-carvone only, while rats trained to generalize odors still respond to D-carvone.

Methionine homozygosity at codon 129 in the prion protein is associated with white matter reduction and enlargement of CSF compartments in healthy volunteers and schizophrenic patients

Twin studies point toward a substantial heritability in individual variations in the size of the human brain. However, the etiology is largely unknown. The prion protein (gene name: PRNP) aids cellular resistance to oxidative stress and neurodegeneration and is involved in neurodevelopment. This study examines the influence of a polymorphism in the PRNP gene on brain morphology in 47 healthy males and 43 male schizophrenic patients. All subjects underwent identical MRI scanning sessions followed by segmentation in cerebrospinal fluid (CSF), gray and white matter tissue, and genotyping for a biallelic polymorphism in PRNP (Met129Val). Genotype and allele frequencies did not differ between schizophrenic patients and controls but the polymorphism was associated with white matter tissue reduction (P = 0.024) and enlargement of CSF compartments (P = 0.039). These findings suggest that homozygosity for methionine at codon 129 is associated with decreased white matter tissue and larger CSF volume in right-handed male healthy volunteers and schizophrenic patients. This, however, being a novel finding, should warrant further investigation.

Association of an interleukin-1beta genetic polymorphism with altered brain structure in patients with schizophrenia

OBJECTIVE

This study investigated the effect on brain morphology of an interleukin-1beta genetic polymorphism (C-->T transition at position -511) in patients with schizophrenia.

METHOD

In vivo magnetic resonance imaging and genotype analysis were used in the examination of 44 male schizophrenic patients and 48 healthy male comparison subjects.

RESULTS

No association between the interleukin-1beta polymorphism and schizophrenia was detected. Within the patient group, bifrontal-temporal gray matter volume deficits and generalized white matter tissue deficits in allele 2 carriers (genotype T/T or C/T) were found. In contrast, the interleukin-1beta polymorphism had no influence on brain morphology within the healthy subjects.

CONCLUSIONS

The data suggest that allele 2 within the promoter region of the interleukin-1beta gene at position -511 contributes to structural brain alterations in patients with schizophrenia.

Microsatellite analysis in rheumatoid arthritis synovial fibroblasts

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic disease characterised by irreversible destruction of the affected joints. As aggressive transformed-appearing synovial fibroblasts are commonly found at the site of invasion of the rheumatoid synovium into the adjacent cartilage and bone, the presence of microsatellite instability (MSI) and expression of mismatch repair enzymes as a possible mechanism in the alteration of these cells was examined.

METHODS

DNA was extracted from the synovial fibroblasts and blood of 20 patients with long term RA undergoing joint replacement, and the presence of MSI was studied at 10 microsatellite loci. In addition, immunohistochemistry was performed to evaluate the expression of the two major mismatch repair enzymes (hMLH1 and hMSH2) in rheumatoid synovium.

RESULTS

MSI could not be detected in any of the fibroblast cell populations derived from the 20 different rheumatoid synovial samples. In addition, strong expression of mismatch repair enzymes could be seen in numerous cells, including fibroblasts, throughout the synovium.

CONCLUSIONS

Applying the currently used and established markers for MSI, the data show for the first time that MSI does not appear to have an important role in alteration of rheumatoid synovial fibroblasts into an aggressive phenotype. On the other hand, strong mismatch repair enzyme synthesis in rheumatoid synovium supports the hypothesis of continuing DNA repair, presumably due to long term, inflammation induced DNA damage.