A comparison of 1995 WHO classification with 2003 ISN/RPS classification of lupus nephritis: a single centre observation.

BACKGROUND: In the past, lupus nephritis was histologically classified according to the 1995 WHO Classification. With the introduction of the 2003 ISN/RPS Classification, many nephropathology services converted to this new classification. This study was undertaken to compare both classification systems in a single centre practice. METHODS: 103 consecutive adequate renal biopsies initially reported as lupus nephritis in the Department of Pathology, Faculty of Medicine, University of Malaya were reassessed using the criteria of both the 1995 WHO Classification and the 2003 ISN/ RPS Classification. RESULTS: The relative prevalence for each class using the WHO Classification were: Class I (1%), Class II (8.7%), Class III (6.8%), Class IV (60.2%), Class V (20.4%), Class VI (2.9%) while the prevalence using the 2003 ISN/RPS Classification were: Class I (1%), Class II (8.7%), Class III (6.8%), Class IV (61.2%), Class V (21.3%), Class VI (1%). Both classifications were essentially comparable with regards to Classes I, II and III. The differences in Classes IV, V and VI were significant in potential to alter patient management. The identification of segmental lesions (Class IV-S) over and above a global nephritis (Class IV-G) deserves more focused clinicopathological studies to gauge whether these groups have different clinical manifestations and outcomes. With regards Class V, the ISN/RPS system, by requiring that all mixed classes be stipulated in the diagnostic line, minimizes the chances of patients missing out on additional treatment. The ISN/ RPS system has stricter criteria for Class VI, which again minimizes patients missing out on therapy. On the whole, the ISN/RPS system is more user-friendly as criteria are more clearly defined which translates to more benefits to patient care.

E-cadherin downregulation at the infiltrating tumour front is associated with histological grade and stage in colorectal carcinoma of Malaysians.

Loss of E-cadherin, a 120 kDA transmembrane glycoprotein responsible for cell-cell adhesion, is one of the hallmarks of epithelial-mesenchymal-transition (EMT). E-cadherin expression was immunohistochemically studied in 94 histopathologically re-confirmed colorectal carcinomas (CRC) using a monoclonal antibody to E-cadherin (Dako: Clone NCH-38) on a Ventana Benchmark XT automated system. Each case was assessed for E-cadherin immunopositivity at two separate locations viz the tumour centre (TC) as well as the infiltrating front (IF). Expression was semiquantitated for proportion of immunopositive malignant cells as 0 (negative), 1 (1-25% staining), 2 (26-50% staining), 3 (51-75% staining) and 4 (>75% staining) and staining intensity: 0 (negative), 1 (weak), 2 (moderate) and 3 (strong). The final histoscore of E-cadherin immunopositivity was arbitrarily computed as proportion of immunopositivity multiplied by staining intensity of the malignant cells. E-cadherin histoscores were significantly lower at the IF (4.5±2.5) compared with TC (10.7±2.4). Furthermore, the histoscores were significantly reduced at the IF of 49 TNM III+IV tumours (3.6±2.5) compared with 45 II+III CRC (5.4±2.2). Reduction of E-cadherin expression was also noted in the 23 high grade (TC=8.6±3.2; IF=2.6±2.3) compared with 71 low grade tumours (TC=11.4±1.5; IF=5.1±2.3). E-cadherin is downregulated at the infiltrating front of CRC, possibly marking for EMT at this location. The downregulation is further enhanced amongst late stage and high grade tumours compared with earlier stage and low grade tumours; findings which are similar to that noted in CRC of other populations.

The immunohistochemistry signature of mismatch repair (MMR) proteins in a multiethnic Asian cohort with endometrial carcinoma.

Endometrial cancer is the most common gynecologic cancer in developed countries and is rising in incidence globally. Although the 5-year survival rates are >80%, factors beyond conventional pathologic features that predict clinical outcomes are still being elucidated. The aims of this study were to define the prevalence and associations of deficient mismatch repair (dMMR) protein expression (MLH1, MSH2, MSH6, PMS2) by immunohistochemistry in a multiethnic Southeast Asian cohort with endometrioid endometrial cancer. A total of 77 patients with adequate formalin-fixed paraffin-embedded specimens were identified. The sections were stained in 2 centers for 4 MMR proteins and examined by 2 independent specialist histopathologists. The mean age for the cohort was 58.6 yr, with 19.4% (15/77) of patients' cancers showing loss of 2 MMR proteins. All 13 cancers with absent MLH1 showed PMS2 loss (13/15), whereas absent MSH2 correlated with MHS6 loss (2/15). There were no significant differences for dMMR cases in age, body mass index, histopathologic characteristics, and clinical outcomes. In dMMR cases, an overrepresentation of patients of Indian ethnic origin was observed compared with Chinese and Malays. These findings suggest that dMMR protein expression in a Southeast Asian endometrial cancer cohort does not correlate with disease outcomes.

A multi-ethnic proteomic profiling analysis in Alzheimer's disease identifies the disparities in dysregulation of proteins and pathogenesis.

Background: Alzheimer's disease (AD) is the most common type of dementia that affects the elderly population. Lately, blood-based proteomics have been intensively sought in the discovery of AD biomarkers studies due to the capability to link external environmental factors with the development of AD. Demographic differences have been shown to affect the expression of the proteins in different populations which play a vital role in the degeneration of cognitive function. Method: In this study, a proteomic study focused on Malaysian Chinese and Malay prospects was conducted. Differentially expressed proteins (DEPs) in AD patients and normal controls for Chinese and Malays were identified. Functional enrichment analysis was conducted to further interpret the biological functions and pathways of the DEPs. In addition, a survey investigating behavioural practices among Chinese and Malay participants was conducted to support the results from the proteomic analysis. Result: The variation of dysregulated proteins identified in Chinese and Malay samples suggested the disparities of pathways involved in this pathological condition for each respective ethnicity. Functional enrichment analysis supported this assumption in understanding the protein-protein interactions of the identified protein signatures and indicate that differentially expressed proteins identified from the Chinese group were significantly enriched with the functional terms related to Aß/tau protein-related processes, oxidative stress and inflammation whereas neuroinflammation was associated with the Malay group. Besides that, a significant difference in sweet drinks/food intake habits between these two groups implies a relationship between sugar levels and the dysregulation of protein APOA4 in the Malay group. Additional meta-analysis further supported the dysregulation of proteins TF, AHSG, A1BG, APOA4 and C4A among AD groups. Conclusion: These findings serve as a preliminary understanding in the molecular and demographic studies of AD in a multi-ethnic population.

Impact of leptin receptor gene variants on risk of non-alcoholic fatty liver disease and its interaction with adiponutrin gene.

BACKGROUND AND AIM: Genetic polymorphism has been implicated as a factor for the occurrence of non-alcoholic fatty liver disease (NAFLD). This study attempted to assess whether polymorphisms in the leptin receptor (LEPR) gene and its combined effect with patatin-like phospholipase domain-containing protein 3 (PNPLA3/adiponutrin) are associated with risk of NAFLD. METHODS: A total of 144 biopsy-proven NAFLD and 198 controls were genotyped using the Sequenom MassARRAY platform. RESULTS: We observed a significant association between the LEPR rs1137100 and rs1137101 with susceptibility to NAFLD (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.18-2.28, P = 0.003; and OR 1.61, 95% CI 1.11-2.34, P = 0.013, respectively) and to non-alcoholic steatohepatitis (OR 1.49, 95% CI 1.05-2.12, P = 0.026; and OR 1.57, 95% CI 1.05-2.35, P = 0.029, respectively). The LEPR rs1137100 is also associated with simple steatosis (OR 2.27, 95% CI 1.27-4.08, P = 0.006). Analysis of gene-gene interaction revealed a strong interaction between the LEPR and PNPLA3 genes (empirical P = 0.001). The joint effect of LEPR and PNPLA3 greatly exacerbated the risk of NAFLD (OR 3.73, 95% CI 1.84-7.55, P < 0.0001). The G allele of rs1137100 is associated with lower fibrosis score (OR 0.47, 95% CI 0.28-0.78, P = 0.001). CONCLUSIONS: We report an association between variants of LEPR rs1137100 and rs1137101 with risk of NAFLD. This study suggests that rs1137100, specifically the G allele, is associated with a less severe form of liver disease in patients with NAFLD. The interaction between LEPR and PNPLA3 genes showed increased risk of NAFLD compared to either gene alone.

A multi-ethnic study of a PNPLA3 gene variant and its association with disease severity in non-alcoholic fatty liver disease.

The adiponutrin (PNPLA3) rs738409 polymorphism has been found to be associated with susceptibility to non-alcoholic fatty liver disease (NAFLD) in various cohorts. We further investigated the association of this polymorphism with non-alcoholic steatohepatitis (NASH) severity and with histological features of NAFLD. A total of 144 biopsy-proven NAFLD patients and 198 controls were genotyped for PNPLA3 gene polymorphism (rs738409 C>G). The biopsy specimens were histologically graded by a qualified pathologist. We observed an association of G allele with susceptibility to NAFLD in the pooled subjects (OR 2.34, 95% CI 1.69-3.24, p < 0.0001), and following stratification, in each of the three ethnic subgroups, namely Chinese, Indian and Malay (OR 1.94, 95% CI 1.12-3.37, p = 0.018; OR 3.51, 95% CI 1.69-7.26, p = 0.001 and OR 2.05, 95% CI 1.25-3.35, p = 0.005, respectively). The G allele is associated with susceptibility to NASH (OR 2.64, 95% CI 1.85-3.75, p < 0.0001), with NASH severity (OR 1.85, 95% CI 1.05-3.26, p = 0.035) and with presence of fibrosis (OR 1.95, 95% CI 1.17-3.26, p = 0.013) but not with simple steatosis nor with other histological parameters. Although the serum triglyceride level is significantly higher in NAFLD patients compared to controls, the G allele is associated with decreased level of triglycerides (p = 0.029) in the NAFLD patients. Overall, the rs738409 G allele is associated with severity of NASH and occurrence of fibrosis in patients with NAFLD.

Clinical predictors of non-diabetic renal disease and role of renal biopsy in diabetic patients with renal involvement: a single centre review.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is reportedly the leading cause of end-stage renal disease (ESRD) worldwide. However, non-diabetic renal diseases (NDRD) are not uncommon among T2DM patients with renal involvement. Our study aimed to examine the prevalence of NDRD in T2DM and clinical markers for diabetic nephropathy (DN) and NDRD and to determine the role of renal biopsy in T2DM patients and its impact on clinical practice. METHODS: We conducted a retrospective analysis of T2DM patients in whom renal biopsies were performed from January 2004 to March 2008 (n = 110). RESULTS: Biopsy results were divided into three groups: group I/pure DN (62.7%), group II/isolated NDRD (18.2%), and group III/mixed lesions (19.1%). The causes of NDRD in decreasing order of frequency were acute interstitial nephritis, glomerulonephritides, hypertensive renal disease, and acute tubular necrosis. Significant clinical markers for DN are presence of diabetic retinopathy and longer duration of diabetes. For NDRD, useful clinical markers include the presence of acute renal failure and microscopic hematuria. In the DN subgroup, Indians had significantly shorter duration of diabetes on biopsy compared with Malays and Chinese. CONCLUSIONS: NDRD is prevalent in T2DM patients, and given its potentially treatable nature, renal biopsy should be considered in T2DM patients with nephropathy, especially in those with atypical features.

CD133 marks for colorectal adenocarcinoma.

CD133, a marker which has been advocated to mark colorectal carcinoma "stem or tumour initiating cells" is amongst the frequently studied markers in colorectal cancer. A study was conducted at the Department of Pathology, University of Malaya Medical Centre to determine the expression of CD133 in 56 archived, formalin-fixed, paraffin-embedded colorectal adenocarcinoma in comparison with adjacent benign colorectal epithelium by immunohistochemical staining for CD133 expression. CD133 immunopositivity was determined as staining at the glandular luminal surface or in the intraluminal debris. Expression was semiquantitated for (1) proportion of CD133 immunopositivity in the malignant or adjacent benign colorectal epithelium and (2) intensity of staining. The final score of CD133 immunopositivity was arbitrarily taken as proportion of CD133 immunopositivity multiplied by intensity of staining in both the malignant and adjacent benign colorectal epithelium. CD133 expression was observed in significantly increased frequency in 49 (87.5%) colorectal adenocarcinoma compared with 15 (26.8%) of the adjacent benign colorectal epithelium (p<0.05). In terms of immunopositivity score (proportion of CD133 immunopositivity multiplied by intensity of staining), colorectal adenocarcinoma had a mean arbitrary score of 8.5 which was significantly higher than the mean immunopositivity score of 0.5 of the adjacent benign colorectal epithelium (p<0.05). In addition, the maximum immunopositivity score for the adjacent benign colorectal epithelium was 4, while 38 (67.9%) of colorectal adenocarcinoma had scores >4. This study shows that CD133 is able to mark colorectal adenocarcinoma but it is still unclear at this juncture whether CD133 is indeed a marker for colorectal adenocarcinoma "stem cells".

Human papillomavirus in cervical cancers of Malaysians.

AIM: With cervical carcinoma remaining the second leading cancer among Malaysian women, it is imperative to clarify the prevalence of human papillomavirus (HPV) in this respect, considering the dearth of local information. MATERIAL AND METHODS: Formalin-fixed, paraffin-embedded (FP) tissues of 29 invasive cervical carcinoma cases, diagnosed between 1 January 1991 and 31 December 1992, fresh, frozen (FF) and paired FP tissues of 43 cases diagnosed between 1 January 1995 and 31 December 2000, and 21 FF normal control cervices were subjected to polymerase chain amplification (PCR) for HPV following successful amplification of a 268 bp ß-globin fragment using primers specific for HPV types 6, 11, 16 and 18 and consensus L1 ORF (MY09/11). RESULTS: HPV was detected in 69.0% of the cases diagnosed in the earlier, 88.4% of those in the later period and 4.8% of the normal control cervices. HPV 16 formed 80.0% of the HPV types in the earlier and 55.3% in the later period, while HPV 18 formed 5% in the earlier and 13.2% in the later. HPV 16 was more common in squamous (56.4%) than adeno/adenosquamous carcinomas (35.3%), while HPV 18 was detected in 17.6% of adeno/adenosquamous and 5.5% squamous carcinomas. CONCLUSION: HPV prevalence in invasive cervical carcinoma of Malaysians is similar to that observed worldwide. Together, HPV 16 and 18 constituted 85% of the HPV types responsible for cervical carcinogenesis in Malaysians in the earlier and 68% in the later period. Thus, the use of current vaccines should lower cervical carcinoma rate significantly.

Implications of continued upregulation of p16(INK4a) through the evolution from high-grade squamous intraepithelial lesion to invasive squamous carcinoma of the cervix.

On integration into the host cervical keratinocyte genome, human papillomavirus (HPV) E7 protein binds pRB,releasing E2F from normally incompetent pRB-E2F complexes and allowing propagation of G1-S transition by the E2F. p16(INK4a), a tumour suppressor protein, increases in reflex response to counter this. 29 histologically re-confirmed low-grade squamous intraepithelial lesions (LSIL), 27 high-grade squamous intraepithelial lesions (HSIL) and 30 invasive cervical squamous carcinoma (SCC) were immunohistochemically stained for p16(INK4a) expression using the CINtec Histology Kit (REF 9511, mtm laboratories AG, Heidelberg, Germany) to re-affirm the notion that integration of HPV occurs predominantly in SCC and possibly HSIL and less in LSIL and normal squamous epithelium (NSqE). Implicit was also the attempt to understand the role of E2F, as indicated by p16(INK4a), in evolution of SCC from HSIL. No ethnic predilection was noted for LSIL, HSIL or SCC. Patients with SCC were significantly older by about 14-years compared with HSIL (p < 0.05) while there was no significant age difference between HSIL and LSIL. p16(INK4a) expression was significantly increased (p < 0.05) in both HSIL (88.9%) and SCC (83.3%) compared with LSIL (3.4%) and NSqE (0%); the NSqE being normal squamous epithelium noted in 17 of the LSIL, 19 HSIL and 5 SCC. From these findings there is suggestion that fundamental upstream events viz HPV integration, E7 upregulation followed by E2F activation occurs at point of transformation to HSIL and continues unrelentingly for another one to two decades before hitherto unclear factors convert a non-invasive lesion into an overtly invasive malignant counterpart. Interestingly, the occurrence of HSIL and LSIL in almost the same age group could mean that alteration from episomal to integrated form of HPV may not incur a prolonged incubation period, unlike from HSIL to SCC.

An analysis of predictive biomarkers in routine histopathological reporting of infiltrating ductal breast carcinoma in a tertiary hospital in Malaysia with a focus on limitations and directions for future development.

Predictive biomarkers such as oestrogen (ER) and progesterone (PR) receptors and c-erbB-2 oncoprotein have become a staple in breast cancer reports in the country as they increasingly play an important role in the treatment and prognosis of women with breast cancers. This study reviews the practice of histopathology reporting of these biomarkers in a Malaysian tertiary hospital setting. Retrospective data on demographic, pathological and biomarker profiles of patients with invasive ductal carcinoma who had undergone mastectomy or lumpectomy with axillary node clearance from 2005 to 2006 were retrieved from the Department of Pathology, Penang Hospital and analysed. The prevalence of ER positivity (55.8%), PR positivity (52.5%), c-erbB-2 oncoprotein overexpression (24%) and triple negativity (ER negative, PR negative, c-erbB-2 negative) (15%) by immunohistochemistry were comparable with other studies. Notably, c-erbB-2 overexpression was equivocal (2+) in 15% of cases. Since about a quarter of equivocal (2+) cases usually show amplification by FISH, a small but certain percentage of patients would miss the benefit of anti-c-erbB-2 antibody therapy if FISH is not performed. New ASCO/CAP guidelines on the quantitation of ER and PR will probably increase the prevalence of ER/PR positivity, invariably leading to significant ramifications on the management of patients as more patients would be deemed eligible for endocrine therapy, as well as categorisation of triple negative breast cancers.

A review on omics-based biomarkers discovery for Alzheimer's disease from the bioinformatics perspectives: Statistical approach vs machine learning approach.

Alzheimer's Disease (AD) is a neurodegenerative disease that affects cognition and is the most common cause of dementia in the elderly. As the number of elderly individuals increases globally, the incidence and prevalence of AD are expected to increase. At present, AD is diagnosed clinically, according to accepted criteria. The essential elements in the diagnosis of AD include a patients history, a physical examination and neuropsychological testing, in addition to appropriate investigations such as neuroimaging. The omics-based approach is an emerging field of study that may not only aid in the diagnosis of AD but also facilitate the exploration of factors that influence the development of the disease. Omics techniques, including genomics, transcriptomics, proteomics and metabolomics, may reveal the pathways that lead to neuronal death and identify biomolecular markers associated with AD. This will further facilitate an understanding of AD neuropathology. In this review, omics-based approaches that were implemented in studies on AD were assessed from a bioinformatics perspective. Current state-of-the-art statistical and machine learning approaches used in the single omics analysis of AD were compared based on correlations of variants, differential expression, functional analysis and network analysis. This was followed by a review of the approaches used in the integration and analysis of multi-omics of AD. The strengths and limitations of multi-omics analysis methods were explored and the issues and challenges associated with omics studies of AD were highlighted. Lastly, future studies in this area of research were justified.

Predictors of Acquired T790M Mutation in Patients Failing First- or Second-Generation Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors.

BACKGROUND: This study aims to determine the predictors of acquired exon 20 T790M mutation in advanced non-small cell lung cancer (NSCLC) patients harbouring sensitizing epidermal growth factor receptor (EGFR) mutation following the failure of first- or second-generation EGFR-tyrosine kinase inhibitor (TKI). METHODS: This is a retrospective observational study of NSCLC patients with sensitising EGFR mutation experiencing disease progression (PD) whilst on first- or second-generation EGFR-TKIs with subsequent investigations to detect acquired T790M mutation at the University of Malaya Medical Centre from 1st January 2015 to 31st December 2017. RESULTS: A total of 87 patients were included. Upon PD, acquired T790M mutation was found in 55 (63.2%) patients and was significantly more common in patients who achieved partial response (PR) whilst on the EGFR-TKIs (p = 0.008) or had new lung metastasis upon PD (p = 0.048). It was less frequent in patients who developed new symptomatic brain lesions (p = 0.021). Patients with exon 19 deletion were more likely to acquire T790M mutation compared to those with exon 21 L858R point mutation (p = 0.077). Multivariate analysis revealed PR whilst on EGFR-TKI treatment was an independent predictor of acquiring T790M mutation (p = 0.021), whereas development of new symptomatic brain lesions (p = 0.034) or new lymph node metastases (p = 0.038) upon PD was independently against acquiring T790M mutation. Patients with exon 19 deletion were more likely to acquire T790M mutation compared to those with exon 21 L858R point mutation (odds ratio: 2.3, 95% confidence interval: 0.84-6.25, p = 0.104). CONCLUSION: The best tumour response of PR to first- or second-generation EGFR-TKI treatment independently predicts acquired T790M mutation. Patients with exon 19 deletion are likely to acquire T790M mutation. This would prove useful for clinicians to prognosticate and plan subsequent treatments for patients with advanced NSCLC harbouring EGFR mutations.

Description, molecular characteristics and Wolbachia endosymbionts of Onchocerca borneensis Uni, Mat Udin & Takaoka n. sp. (Nematoda: Filarioidea) from the Bornean bearded pig Sus barbatus Müller (Cetartiodactyla: Suidae) of Sarawak, Malaysia.

BACKGROUND: The genus Onchocerca Diesing, 1841 includes species of medical importance, such as O. volvulus (Leuckart, 1893), which causes river blindness in the tropics. Recently, zoonotic onchocercosis has been reported in humans worldwide. In Japan, O. dewittei japonica Uni, Bain & Takaoka, 2001 from wild boars is a causative agent for this zoonosis. Many filarioid nematodes are infected with Wolbachia endosymbionts which exhibit various evolutionary relationships with their hosts. While investigating the filarial fauna of Borneo, we discovered an undescribed Onchocerca species in the bearded pig Sus barbatus Müller (Cetartiodactyla: Suidae). METHODS: We isolated Onchocerca specimens from bearded pigs and examined their morphology. For comparative material, we collected fresh specimens of O. d. dewittei Bain, Ramachandran, Petter & Mak, 1977 from banded pigs (S. scrofa vittatus Boie) in Peninsular Malaysia. Partial sequences of three different genes (two mitochondrial genes, cox1 and 12S rRNA, and one nuclear ITS region) of these filarioids were analysed. By multi-locus sequence analyses based on six genes (16S rDNA, ftsZ, dnaA, coxA, fbpA and gatB) of Wolbachia, we determined the supergroups in the specimens from bearded pigs and those of O. d. dewittei. RESULTS: Onchocerca borneensis Uni, Mat Udin & Takaoka n. sp. is described on the basis of morphological characteristics and its genetic divergence from congeners. Molecular characteristics of the new species revealed its close evolutionary relationship with O. d. dewittei. Calculated p-distance for the cox1 gene sequences between O. borneensis n. sp. and O. d. dewittei was 5.9%, while that between O. d. dewittei and O. d. japonica was 7.6%. No intraspecific genetic variation was found for the new species. Wolbachia strains identified in the new species and O. d. dewittei belonged to supergroup C and are closely related. CONCLUSIONS: Our molecular analyses of filarioids from Asian suids indicate that the new species is sister to O. d. dewittei. On the basis of its morphological and molecular characteristics, we propose to elevate O. d. japonica to species level as O. japonica Uni, Bain & Takaoka, 2001. Coevolutionary relationships exist between the Wolbachia strains and their filarial hosts in Borneo and Peninsular Malaysia.

Historical development of the renal histopathology services in Malaysia.

Western-style medicine was introduced to Malaya by the Portuguese, Dutch and British between the 1500s and 1800s. Although the earliest pathology laboratories were developed within hospitals towards the end of the 19th Century, histopathology emerged much later than the biochemistry and bacteriology services. The University Departments of Pathology were the pioneers of the renal histopathology diagnostic services. The Department of Pathology, University of Malaya (UM) received its first renal biopsy on 19 May 1968. Hospital Universiti Kebangsaan Malaysia (HUKM) and Hospital Universiti Sains Malaysia (HUSM) started their services in 1979 and 1987 respectively. It is notable that the early services in these University centres caterred for both the university hospitals and the Ministry of Health (MOH) until the mid-1990s when MOH began to develop its own services, pivoted on renal pathologists trained through Fellowship programmes. Currently, key centres in the MOH are Kuala Lumpur Hospital, Sultanah Aminah Hospital Johor Bahru and Malacca Hospital. With the inclusion of renal biopsy interpretation in the Master of Pathology programmes, basic renal histopathology services became widely available throughout the country from 2000. This subsequently filtered out to the private sector as more histopathologists embraced private practice. There is now active continuing professional development in renal histopathology through clinicopathological dicussions, seminars and workshops. Renal research on amyloid nephropathy, minimal change disease, IgA nephropathy, fibrillary glomerulonephritis, lupus nephritis and microwave technology have provided an insight into the patterns of renal pathology and changing criteria for biopsy. More recently, there has been increasing involvement of renal teams in clinical trials, particularly for lupus nephritis and renal transplant modulation.

Molecular testing for advanced non-small cell lung cancer in Malaysia: Consensus statement from the College of Pathologists, Academy of Medicine Malaysia, the Malaysian Thoracic Society, and the Malaysian Oncological Society.

In the recent years, increased understanding of the molecular profiles of non-small cell lung cancer (NSCLC) has allowed for targeted treatment of actionable genetic mutations. The management of NSCLC now requires multiple molecular tests to guide the treatment strategy. In the light of this, there is a need to establish a molecular testing consensus statement for advanced NSCLC patients in Malaysia. This Malaysian consensus statement was developed by a panel of experts, chaired by a pathologist and composed of three other pathologists, four respiratory physicians and three oncologists. It reflects currently available scientific data and adaptations of recommendations from international guidelines to the local landscape. Expert recommendations on different aspects of molecular testing agreed upon by the panel are provided as structured discussions. These recommendations address the appropriate patients and samples to be tested, as well as when and how these tests should be performed. The algorithms for molecular testing in metastatic NSCLC, in the first line setting and upon disease progression beyond first line therapy, were developed.

Detection of the human papillomavirus in cervical carcinoma: a comparison between non-isotopic in-situ hybridisation and polymerase chain reaction as methods for detection in formalin-fixed, paraffin-embedded tissues.

Cervical carcinoma, the second most common malignancy in Malaysian females, is aetiologically linked to the human papillomavirus (HPV). A study was conducted at the Department of Pathology, University of Malaya Medical Centre to compare the identification of HPV 6, 11, 16 and 18 in 40 archived formalin-fixed, paraffin-embedded cervical carcinoma by non-isotopic in-situ hybridisation (NISH) and polymerase chain reaction (PCR). HPV L1 ORF consensus PCR was also carried in cases which were negative on HPV type-specific PCR. NISH detected HPV 16 in 13 (32.5%) cases with one case demonstrating a concomitant HPV 18. beta-globin DNA PCR was carried out on the same paraffin block as for NISH in 27 cases and on a different paraffin block in 13, with amplification in 9 of the former and 3 of the latter. Thus only 12 cases were subjected to further HPV PCR. HPV was detected in 10 (83.3%) with HPV 16 in 9 cases and HPV L1 ORF in one. When using the same paraffin block for both methods of HPV detection, NISH detected HPV in 6 and PCR in 7. NISH failed to detect HPV in a case detected by PCR. 2 cases were negative for HPV using both methods. Hence, HPV detection results by NISH and PCR were concordant in 88.9%. Interestingly, NISH detected HPV in 2 cases with non-amplifiable beta-globin DNA. Using an alternative paraffin block for HPV PCR from NISH, HPV DNA was detected in 3 cases, two of which also showed type-specific positivity on NISH. The third case did not reveal type-specific positivity with NISH or PCR but demonstrated HPV DNA on L1 ORF consensus PCR. It thus appears that PCR and NISH can be successfully used to detect HPV in formalin-fixed, paraffin-embedded tissue and in the presence of intact DNA NISH may be as sensitive as PCR.

Association of Ki67 with raised transaminases in hepatocellular carcinoma.

Transaminase enzymes, alanine (ALT) and aspartate transaminase (AST), have been reported to be raised and implicated to have prognostic value in hepatocellular carcinoma (HCC). Ki67, a marker of cellular proliferative activity, has also been noted to be increased in HCC. A study was conducted at the Department of Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur to determine the possible association of proliferative activity, as determined by Ki67, with the transaminase enzymes. 31 cases of histologically diagnosed HCC who underwent tumour resection were retrieved from departmental archives. The patients' ages ranged between 40 to 79 years with a mean of 58.3 years. There was a male preponderance with M:F = 2.9:1. Ethnic Chinese formed 83.9% of the cases. 4 microm sections, cut from the formalin-fixed, paraffin-embedded tumour tissue block of each case, were immunohistochemically stained with Ki67 (DAKO monoclonal MIB-1) using the commercial DakoCytomation EnVision+System-HRP kit. The latest ALT and AST levels, assayed within 7 days prior to tumour resection, were retrieved from the patients' case records. 24 (77.4%) HCC demonstrated elevation of either ALT and/or AST. 27 (87.1%) HCC were immunopositive for Ki67. Ki67 immunoexpression was significantly correlated with raised transaminases (p<0.05). Hypothetically, the mechanism by which this phenomenon may occur may simply be release of transaminases due to destruction of hepatocytes by the cancer. Thus rising levels of the transaminases could signal a more rapid growth of the tumour and these routinely performed tests can be of prognostic value in management of HCC patients.

Integrative machine learning analysis of multiple gene expression profiles in cervical cancer.

Although most of the cervical cancer cases are reported to be closely related to the Human Papillomavirus (HPV) infection, there is a need to study genes that stand up differentially in the final actualization of cervical cancers following HPV infection. In this study, we proposed an integrative machine learning approach to analyse multiple gene expression profiles in cervical cancer in order to identify a set of genetic markers that are associated with and may eventually aid in the diagnosis or prognosis of cervical cancers. The proposed integrative analysis is composed of three steps: namely, (i) gene expression analysis of individual dataset; (ii) meta-analysis of multiple datasets; and (iii) feature selection and machine learning analysis. As a result, 21 gene expressions were identified through the integrative machine learning analysis which including seven supervised and one unsupervised methods. A functional analysis with GSEA (Gene Set Enrichment Analysis) was performed on the selected 21-gene expression set and showed significant enrichment in a nine-potential gene expression signature, namely PEG3, SPON1, BTD and RPLP2 (upregulated genes) and PRDX3, COPB2, LSM3, SLC5A3 and AS1B (downregulated genes).

DNA mismatch repair and CD133-marked cancer stem cells in colorectal carcinoma.

BACKGROUND: Except for a few studies with contradictory observations, information is lacking on the possibility of association between DNA mismatch repair (MMR) status and the presence of cancer stem cells in colorectal carcinoma (CRC), two important aspects in colorectal carcinogenesis. METHODS: Eighty (40 right-sided and 40 left-sided) formalin-fixed, paraffin-embedded primary CRC were immunohistochemically studied for CD133, a putative CRC stem cell marker, and MMR proteins MLH1, MSH2, MSH6 and PMS2. CD133 expression was semi-quantitated for proportion of tumor immunopositivity on a scale of 0-5 and staining intensity on a scale of 0-3 with a final score (units) being the product of proportion and intensity of tumor staining. The tumor was considered immunopositive only when the tumor demonstrated moderate to strong intensity of CD133 staining (a decision made after analysis of CD133 expression in normal colon). Deficient MMR (dMMR) was interpreted as unequivocal loss of tumor nuclear staining for any MMR protein despite immunoreactivity in the internal positive controls. RESULTS: CD133 was expressed in 36 (90.0%) left-sided and 28 (70.0%) right-sided tumors (p < 0.05) and CD133 score was significantly higher in left- (mean ± SD = 9.6 ± 5.3 units) compared with right-sided tumors (mean ± SD = 6.8 ± 5.6 units) p < 0.05). dMMR was noted in 14 (35%) right-sided and no (0%) left-sided CRC. When stratified according to MMR status, dMMR cases showed a lower frequency of CD133 expression (42.9%) and CD133 score (mean ± SD = 2.5 ± 3.6 units) compared with pMMR tumors on the right (frequency = 84.6%; mean score ± SD = 9.2 ± 5.0 units) as well as pMMR tumors on the left (frequency = 90.0%; mean score ± SD = 9.6 ± 5.3 units) (p < 0.05). Interestingly, frequencies of CD133 immunoreactivity and CD133 scores did not differ between pMMR CRC on the right versus the left (p > 0.05). CONCLUSION: Proficient MMR correlated with high levels of CD133-marked putative cancer stem cells in both right- and left-sided tumors, whereas significantly lower levels of CD133-marked putative cancer stem cells were associated with deficient MMR status in colorectal carcinomas found on the right.