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The importance of distinguishing and reporting different perinuclear ANCA (P-ANCA) immunofluorescence patterns: a prospective study
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PATHOLOGY 2011 ABSTRACT SUPPLEMENT
pharyngeal pouch is considered to be the underlying factor for the development of infection. Our patient responded well to a course of intravenous and oral antibiotic therapy and her clinical symptoms significantly improved. Our case presents some rare features of oesophageal actinomycosis and also demonstrates the importance of considering this diagnosis in symptomatic patients even in the absence of any obvious underlying condition. OXYHAEMOGLOBIN AND PROTEIN INTERFERENCE ON SPECTROPHOTOMETRIC DETECTION OF CEREBROSPINAL FLUID BILIRUBIN Lan Nguyen Department of Chemical Pathology, St Vincent’s Hospital, Sydney, NSW, Australia Aim: Diagnosis of subarachnoid haemorrhage (SAH) may involve the spectrophotometric analysis of cerebrospinal fluid for net bilirubin absorbance (NBA) and net oxyhaemoglobin absorbance (NOA). NBA>0.007 AU is supportive of a diagnosis of SAH. A limitation is that oxyhaemoglobin and total protein (TP) can interfere with NBA measurement such that according to published guidelines, results may be deemed inconclusive if NOA>0.1 AU or TP>1000 mg/L. The aim of this study was to assess the interference of oxyhaemoglobin and TP on NBA measurement. Method: Increasing amounts of haemolysate was added to samples with a NBA of 0.007, 0.14 or 0.028 AU. Increasing amounts of human albumin was added to samples with a NBA of 0.01 AU and NOA 0.09 AU. Precision was also evaluated. Results: At an initial NBA ¼ 0.007 AU, increasing NOA to 0.025 and 0.094 AU decreased NBA by –29% and –77%, respectively. At an initial NBA ¼ 0.014 and 0.028 AU, a significant decrease occurred at NOA ¼ 0.269 AU (–36%) and NOA ¼ 0.253 (–26%), respectively. Increasing TP to 1400 mg/L decreased NBA by – 0.003AU (–30%). Precision was satisfactory. Conclusion: Oxyhaemoglobin significantly interferes with a NBA close to the decision point at a level lower than suggested by the guidelines. Samples with a higher NBA are more resistant to oxyhaemoglobin interference. TP up to 1400 mg/L would only significantly interfere if NBA was close to the decision point. These interferences are not seen with direct bilirubin measurement. Re-evaluation of the guidelines may be indicated. PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA WITH UNDERLYING AETIOLOGY RELATED TO EPSTEIN-BARR VIRUS AND HUMAN HERPESVIRUS 8 M. N. Norizal1, A. C. Patricia2, K. T. Wong2 1 Faculty of Medicine, MARA Technology University, Selangor and 2Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia Background: Primary central nervous system lymphoma (PCNSL) is uncommon but least favourable due to its low patient survival. It is frequently found in the supratentorial region and presents with focal neurological deficits with the main histological classification of diffuse large B-cell lymphoma (DLBL). Chemoand radiotherapy is usually the preferred treatment. Method: This was a retrospective cohort study involving 31 PCNSL cases between 2002 and 2009 in the University Malaya Medical Centre. The case notes, H&E and immunohistochemistry slides were reviewed and staining with mouse anti-LMP1 monoclonal antibody and anti-HHV8 monoclonal antibody was done.
Pathology (2011), 43(S1)
Results: The incidence of PCNSL increased 4-fold in the past 8 years with a median age of 56.3 years. The locations of the tumour were commonly seen in the basal ganglia/paraventricular and parietal regions (22.6%). The majority were histologically diagnosed as DLBL (80.6%), with features of CD20 positive (96.8%), angioencentricity (71%), parenchymal infiltration (28%) and necrosis (58.1%). 51.6% showed prominent LPM1 expression but lacked HHV8 expression (6.5%). Median survival was 5 1.39 months with the sole significant predictive survival indicator being treatment response. Conclusion: There was a notable increase in incidence of PCNSL but no significant histological predictor on prognosis was seen in our study. THE IMPORTANCE OF DISTINGUISHING AND REPORTING DIFFERENT PERINUCLEAR ANCA (P-ANCA) IMMUNOFLUORESCENCE PATTERNS: A PROSPECTIVE STUDY S. B. Perel, K. M. Prain, R. J. Wilson, P. G. Hogan, D. Gillis, R. C. W. Wong Division of Immunology, Pathology Queensland Central Laboratory, Brisbane, Qld, Australia The 1999 International ANCA consensus statement does not require laboratories to distinguish between different perinuclear ANCA (P-ANCA) IIF patterns, including those produced by positive anti-nuclear antibodies (ANA). However, they recommend correlation with results of MPO/PR3-ANCA ELISA testing. Aims: To investigate the clinical associations of the ‘classical/ textbook’ P-ANCA, atypical P-ANCA (AP) and ANA/uninterpretable patterns, with or without MPO/PR3-ANCA ELISA results, to determine whether different P-ANCA patterns should be distinguished and reported. Methods: All routine ANCA requests (n ¼ 3544) from January to April 2010 were studied prospectively regarding P-ANCA IIF patterns, MPO/PR3-ANCA ELISA results, and clinical/other laboratory evidence of vasculitis. Results: Four hundred and thirty-six (436) samples demonstrated positive perinuclear ANCA immunofluorescence, including the classical P-ANCA pattern (n ¼ 45), atypical P-ANCA pattern (n ¼ 163) and ANA/uninterpretable patterns (n ¼ 228). The ‘classical/textbook’ P-ANCA pattern had a significantly stronger association with vasculitis (31/45) compared to the atypical P-ANCA pattern (2/163), positive ANA/uninterpretable patterns (11/228), or all P-ANCA patterns combined (44/436) (all p values <0.0001). The combination of a positive ELISA result with a classical PANCA pattern was more likely to be associated with vasculitis than a positive ELISA result irrespective of corresponding IIF pattern (25/29 versus 33/62; p < 0.001). Conclusion: This study demonstrates the importance of distinguishing the ‘classical/textbook’ P-ANCA pattern from both atypical P-ANCA and ANA/uninterpretable patterns, especially as the latter two patterns occur more frequently. Combining MPO/ PR3-ELISA and IIF results improves the association with vasculitis compared with either ELISA or IIF results alone. WHAT MAKES A GOOD LEARNING PORTFOLIO FOR PATHOLOGY? Wendy Pryor1, Leah Bloomfield2 1 University of Sydney and 2Royal College of Pathologists of Australasia, Sydney, NSW, Australia
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
PATHOLOGY 2011 ABSTRACT SUPPLEMENT
pharyngeal pouch is considered to be the underlying factor for the development of infection. Our patient responded well to a course of intravenous and oral antibiotic therapy and her clinical symptoms significantly improved. Our case presents some rare features of oesophageal actinomycosis and also demonstrates the importance of considering this diagnosis in symptomatic patients even in the absence of any obvious underlying condition. OXYHAEMOGLOBIN AND PROTEIN INTERFERENCE ON SPECTROPHOTOMETRIC DETECTION OF CEREBROSPINAL FLUID BILIRUBIN Lan Nguyen Department of Chemical Pathology, St Vincent’s Hospital, Sydney, NSW, Australia Aim: Diagnosis of subarachnoid haemorrhage (SAH) may involve the spectrophotometric analysis of cerebrospinal fluid for net bilirubin absorbance (NBA) and net oxyhaemoglobin absorbance (NOA). NBA>0.007 AU is supportive of a diagnosis of SAH. A limitation is that oxyhaemoglobin and total protein (TP) can interfere with NBA measurement such that according to published guidelines, results may be deemed inconclusive if NOA>0.1 AU or TP>1000 mg/L. The aim of this study was to assess the interference of oxyhaemoglobin and TP on NBA measurement. Method: Increasing amounts of haemolysate was added to samples with a NBA of 0.007, 0.14 or 0.028 AU. Increasing amounts of human albumin was added to samples with a NBA of 0.01 AU and NOA 0.09 AU. Precision was also evaluated. Results: At an initial NBA ¼ 0.007 AU, increasing NOA to 0.025 and 0.094 AU decreased NBA by –29% and –77%, respectively. At an initial NBA ¼ 0.014 and 0.028 AU, a significant decrease occurred at NOA ¼ 0.269 AU (–36%) and NOA ¼ 0.253 (–26%), respectively. Increasing TP to 1400 mg/L decreased NBA by – 0.003AU (–30%). Precision was satisfactory. Conclusion: Oxyhaemoglobin significantly interferes with a NBA close to the decision point at a level lower than suggested by the guidelines. Samples with a higher NBA are more resistant to oxyhaemoglobin interference. TP up to 1400 mg/L would only significantly interfere if NBA was close to the decision point. These interferences are not seen with direct bilirubin measurement. Re-evaluation of the guidelines may be indicated. PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA WITH UNDERLYING AETIOLOGY RELATED TO EPSTEIN-BARR VIRUS AND HUMAN HERPESVIRUS 8 M. N. Norizal1, A. C. Patricia2, K. T. Wong2 1 Faculty of Medicine, MARA Technology University, Selangor and 2Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia Background: Primary central nervous system lymphoma (PCNSL) is uncommon but least favourable due to its low patient survival. It is frequently found in the supratentorial region and presents with focal neurological deficits with the main histological classification of diffuse large B-cell lymphoma (DLBL). Chemoand radiotherapy is usually the preferred treatment. Method: This was a retrospective cohort study involving 31 PCNSL cases between 2002 and 2009 in the University Malaya Medical Centre. The case notes, H&E and immunohistochemistry slides were reviewed and staining with mouse anti-LMP1 monoclonal antibody and anti-HHV8 monoclonal antibody was done.
Pathology (2011), 43(S1)
Results: The incidence of PCNSL increased 4-fold in the past 8 years with a median age of 56.3 years. The locations of the tumour were commonly seen in the basal ganglia/paraventricular and parietal regions (22.6%). The majority were histologically diagnosed as DLBL (80.6%), with features of CD20 positive (96.8%), angioencentricity (71%), parenchymal infiltration (28%) and necrosis (58.1%). 51.6% showed prominent LPM1 expression but lacked HHV8 expression (6.5%). Median survival was 5 1.39 months with the sole significant predictive survival indicator being treatment response. Conclusion: There was a notable increase in incidence of PCNSL but no significant histological predictor on prognosis was seen in our study. THE IMPORTANCE OF DISTINGUISHING AND REPORTING DIFFERENT PERINUCLEAR ANCA (P-ANCA) IMMUNOFLUORESCENCE PATTERNS: A PROSPECTIVE STUDY S. B. Perel, K. M. Prain, R. J. Wilson, P. G. Hogan, D. Gillis, R. C. W. Wong Division of Immunology, Pathology Queensland Central Laboratory, Brisbane, Qld, Australia The 1999 International ANCA consensus statement does not require laboratories to distinguish between different perinuclear ANCA (P-ANCA) IIF patterns, including those produced by positive anti-nuclear antibodies (ANA). However, they recommend correlation with results of MPO/PR3-ANCA ELISA testing. Aims: To investigate the clinical associations of the ‘classical/ textbook’ P-ANCA, atypical P-ANCA (AP) and ANA/uninterpretable patterns, with or without MPO/PR3-ANCA ELISA results, to determine whether different P-ANCA patterns should be distinguished and reported. Methods: All routine ANCA requests (n ¼ 3544) from January to April 2010 were studied prospectively regarding P-ANCA IIF patterns, MPO/PR3-ANCA ELISA results, and clinical/other laboratory evidence of vasculitis. Results: Four hundred and thirty-six (436) samples demonstrated positive perinuclear ANCA immunofluorescence, including the classical P-ANCA pattern (n ¼ 45), atypical P-ANCA pattern (n ¼ 163) and ANA/uninterpretable patterns (n ¼ 228). The ‘classical/textbook’ P-ANCA pattern had a significantly stronger association with vasculitis (31/45) compared to the atypical P-ANCA pattern (2/163), positive ANA/uninterpretable patterns (11/228), or all P-ANCA patterns combined (44/436) (all p values <0.0001). The combination of a positive ELISA result with a classical PANCA pattern was more likely to be associated with vasculitis than a positive ELISA result irrespective of corresponding IIF pattern (25/29 versus 33/62; p < 0.001). Conclusion: This study demonstrates the importance of distinguishing the ‘classical/textbook’ P-ANCA pattern from both atypical P-ANCA and ANA/uninterpretable patterns, especially as the latter two patterns occur more frequently. Combining MPO/ PR3-ELISA and IIF results improves the association with vasculitis compared with either ELISA or IIF results alone. WHAT MAKES A GOOD LEARNING PORTFOLIO FOR PATHOLOGY? Wendy Pryor1, Leah Bloomfield2 1 University of Sydney and 2Royal College of Pathologists of Australasia, Sydney, NSW, Australia
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.