Tweaking the ISLH Slide Making Criteria- Is it worth?

  • Shital Joshi Sahyadri Speciality Labs, Pune
  • Rajesh Phatale Sahyadri Speciality Labs, Pune
  • Shashikant Apte Sahyadri Speciality Labs, Pune
  • Rashmi Pareekh Sahyadri Speciality Labs, Pune
Keywords: manual blood smear review, screening criteria, automated hematology analyzers, International consensus group of hematology


 BACKGROUND: Every laboratory is trying its best to release the report in shortest possible time without compromising its quality. In this era, automated analyzer plays a very important role but manual microscopic review of stained blood film is mandatory to identify morphological abnormalities and to authenticate the results of the analyzer. The aim is to evaluate efficacy of our laboratory criteria using automated analyzer for manual peripheral smear review and to reduce the number of samples requiring microscopic blood film review  METHODS-Retrospective study was done on total 526 patients whose samples were collected over a period of 36 months for complete blood count randomly from both inpatient and outpatient population. Based on our experience we have set our slide making criteria which are more stringent than ISLH. We have taken the study population which falls in the range between ISLH criteria and our lab criteria for study. We made comparisons of adapted ISLH criteria with study population laboratory criteria. RESULTS-   Thus, after employing strict screening criteria the yield of true positives was significantly lower than internationally accepted ISLH criteria (Two sample test of proportion, p value < 0.001).                                                                                                                                                             CONCLUSION- The 41 rules of ISLH for slide review of automated CBC and WBC differential were compared with our study population lab criteria. There was significant reduction in microscopic smear review rate using ISLH criteria. False positive rates are high if cut offs are very narrow. Thus, it was found that tweaking ISLH criteria was an unnecessary exercise.


Barnes PW, McFadden SL, Machin SJ, Simson E; International Consensus Group for Hematology. The international consensus group for hematology review: Suggested criteria for action following automated CBC and WBC differential analysis. Lab Hematol 2005;11(2):83-90.

Gene Gulati, Jinming Song, Alina Dulau, Florea Jerald Gong, “Purpose and Criteria for blood smear scan, blood smear examination, and blood smear review”. 2013. Department of Pathology, Anatomy, and Cell Biology Faculty Papers. Paper 103.

Gene L Gulati, Mohammad Alomari, William Kocher, Roland Schwarting; Jefferson Medical College and Thomas Jefferson University Hospital, Philadelphia, PA; Criteria for Blood Smear Review. Laboratory Medicine 2002; 33(5):374-77

Samuel Ricardo Comar, Mariester Malvezzi, Ricardo Pasquini. Evaluation of criteria of manual blood smear review following automated complete blood counts in a large university hospital. Bras Hematol Hemoter 2017 oct-Dec;39(4):306-317

Katyayani Palur, Surekha U Arakeri Effectiveness of the International Consensus Group criteria for manual peripheral smear review. Indian J. Pathol. Microbiol. 2018(3); 61: 360-365.

Pratumvinit B, Wongkrajang P, Reesukumal K, Klinbua C, Niamjoy P. Validation and optimization of criteria for manual smear review following automated blood cell analysis in a large university hospital. Arch Pathol Lab Med 2013;137: 408-14.

Comar SR, Malvezzi M, Pasquini R. Are the review criteria for automated complete blood counts of the international society of laboratory hematology suitable for all hematology laboratories? Rev Bras Hematol Hemoter 2014;36: 219-25.

El-Danasoury AS, Boshnak NH, El Monem RA. Validation of criteria for smear review following automated blood cell analysis in Ain Shams University. Int J Sci Res (Raipur) 2016;5: 484-93.

Original Article