Investigation of Blood and Bone Marrow Samples of Patients with Myelodysplastic Syndrome by Conventional Cytogenetic and Fluorescent In Situ Hybridization Methods

Abstract

Objective: Chromosome abnormalities are observed in 30-50% of myelodysplastic syndrome (MDS) cases. The most common anomalies are trisomy 8, monosomy 7 / 7q-, monosomy 5 / 5q- and 20q-. Conventional cytogenetic and interphase FISH methods are used to detect these anomalies. Although bone marrow is the preferred material for both methods, the suitability of using peripheral blood is also being investigated. The aim of this study is to contribute to the data pool in this area by presenting comparative cytogenetic and interphase FISH examination results in peripheral blood and bone marrow samples of MDS patients who applied to our laboratory. Materials and Methods: Peripheral blood and bone marrow samples of 19 patients with MDS were examined with conventional cytogenetic and iFISH methods using deletion probes specific to the 5q31, 7q22 and 7q31 regions. The data obtained were used to compare the materials and techniques. Results: Conventional cytogenetics: In this technique, the results of peripheral blood and bone marrow samples were concordant in 5 cases (normal karyotypes in 2, and abnormal in 3 cases), and discordant in 12 cases, and in two cases, there was no metaphase in bone marrow samples, while abnormal karyotypes were observed in blood samples. iFISH: Between the results of peripheral blood and bone marrow; for -5/del(5q) there was concordance in 13 cases (positive in two, and negative in three cases), and for -7/del(7q), 10 cases were concordant (positive in one, and negative in 9 cases). The one case that del(5q) and del(7q) were observed together in conventional cytogenetic examination, was positive in iFISH analysis for both anomalies, too. Conclusion: When we evaluate our results together with previous reports, it seems that both methods and both materials have their own advantages and disadvantages. Therefore, we suggest that it would be beneficial to use these two methods and materials in parallel instead of replacing each other.

Keywords

• Myelodysplastic syndrome
• Cytogenetics
• interphase FISH

Miyelodisplastik Sendromlu Olguların Kan ve Kemik İliği Örneklerinin Konvansiyonel Sitogenetik ve Floresan İn Situ Hibridizasyon (FISH) Yöntemiyle İncelenmesi

Abstract

Amaç: Miyelodiplastik sendrom (MDS) olgularının %30-50’sinde kromozom anomalileri gözlenmektedir. En sık gözlenen anomaliler trizomi 8, monozomi 7/7q-, monozomi 5/5qve 20q- olarak belirlenmiştir. Bu anomalilerin saptanmasında konvansiyonel sitogenetik ve interfaz FISH (iFISH) yöntemleri kullanılmaktadır. Her iki yöntem için tercih edilen materyal kemik iliği olmakla birlikte, perifer kanının kullanılmasının uygunluğu da araştırılmaktadır. Bu çalışmada, laboratuvarımıza başvuran MDS hastalarının perifer kanı ve kemik iliği örneklerindeki anomalilerin sitogenetik ve iFISH yöntemleri ile karşılaştırılarak mevcut veri havuzuna katkı sağlanması amaçlanmıştır. Gereç ve Yöntem: MDS tanılı 19 olgunun perifer kanı ve kemik iliği örnekleri konvansiyonel sitogenetik ve 5q31, 7q22 ve 7q31 bölgelerine özgü delesyon problarının kullanıldığı iFISH yöntemleriyle incelenerek, elde edilen veriler örnek tipi ve kullanılan yönteme göre karşılaştırılmıştır. Bulgular: Konvansiyonel sitogenetik yöntemiyle olguların 5’inde periferik kan ve kemik iliği örneklerinde elde edilen sonuçlar arasında (iki olguda normal, üç olguda anormal karyotip) konkordans, 12 olguda diskordans gözlenmiş, iki olguda kemik iliğinde metafaz elde edilemezken, perifer kanında klonal sayı anomalileri saptanmıştır. iFISH yöntemiyle incelemede ise, olguların perifer kanı ve kemik iliği örnekleri arasında, -5/del(5q) incelemesinde 13 olguda (iki olguda pozitif, 11 olguda negatif), -7/del(7q) için 10 olguda (bir olguda pozitif, 9 olguda negatif) konkordans gözlenmiştir. Sitogenetik olarak tek olgunun kemik iliği örneğinde birlikte gözlenen del(5q) ve del(7q) bulguları, hem perifer kanı hem de kemik iliği örneklerinde uygulanan iFISH analizinde de pozitif olarak saptanmıştır. Sonuç: Elde ettiğimiz sonuçlar daha önce bildirilen çalışmalarla birlikte değerlendirildiğinde, her iki yöntem ve her iki örnek tipinin kendilerine özgü avantajlara ve dezavantajlara sahip oldukları gözlenmiştir. Bu durum bu iki yöntem ve örneğin birbirlerinin yerini almak yerine, paralel olarak kullanılmalarının yararlı olacağını düşündürmektedir.

Keywords

• Miyelodisplastik Sendrom
• Sitogenetik
• interfaz FISH

References

1. 1. Haferlach T. The Molecular Pathology of Myelodysplastic Syndrome. Pathobiology 2019;86(1):24-9.
2. 2. Bejar R, Levine R, Ebert B.L. Unraveling the Molecular Pathophysiology of Myelodysplastic Syndromes. J Clin Oncol 2011;29(5): 504-15.
3. 3. Neaim F, Rao P.N, Grody W. Hematopathology, 1st ed., Academic Press. Published by Elsevier Science & Technology 2008.
4. 4. Saitoh K, Miura I. Fluorescence in situ hybridization of progenitor cells obtained by Fluorescence-Activated Cell sorting for the detection of cells affected by hormosome abnormality trisomy 8 in patients with myelodisplastic syndromes. Blood 1998; 92(8): 2886-92.
5. 5. Adema V, Hernandez J, Abáigar M, et al. Application of FISH 7q in MDS patients without monosomy 7 or 7q deletion by conventional G-banding cytogenetics: Does -7/7q- detection by FISH have prognostic value? Leuk Res 2013; 37(4): 416-21.
6. 6. Pellagatti A, Boultwood J. The molecular pathogenesis of the myelodysplastic syndromes. Eur J Haematol 2015;95(1):3-15.
7. 7. Sebaa A, Ades L, Penther D, et al. Incidence of 17p Deletions and TP53 Mutation in Myelodysplastic Syndrome and Acute Myeloid Leukemia with 5q Deletion. Genes Chromosomes Cancer 2012; 51(12):1086-92.
8. 8. Cherry A, Slovak M, Campbell L, et al. Will a peripheral blood (PB) sample yield the same diagnostic and prognostic cytogenetic data as the concomitant bone marrow (BM) in myelodysplasia? Leukemia Research 2012; 36(7): 832-40.

9. 9. Coleman J, Theil K, et al. Diagnostic yield of bone marrow and peripheral blood FISH panel testing in clinically suspected myelodisplastic syndromes and/or acute myeloid leukemia. Am J Clin Pathol 2011;135(6):915-20.
10. 10. Fakhr ZA, Mehrzad V, İzaditabar A, Salehi M. Evaluation of the utility of peripheral blood vs bone marrow in karyotype and fluorescence in situ hybridization for myelodysplastic syndrome diagnosis. J Clin Lab Anal 2018;32:e22586.
11. 11. McGowan-Jordan J, Simons A, Schmid M (Eds).: An International System for Human Cytogenomic Nomenclature (2016). Basel: Karger; 2016.
12. 12. Dowling PK. Mathematics for the cytogenetic technologist. In: The AGT Cytogenetics Laboratory Manual [Internet]. John Wiley & Sons, Ltd; 2017. p. 937-64.
13. 13. Lai Y, Huang X ve ark. Standardized fluorescence in situ hybridization testing based on an appropriate panel of probes more effectively identifies common cytogenetic abnormalities in myelodysplastic syndromes than conventional cytogenetic analysis: A multicenter prospective study of 2302 patients in China. Leukemia Research 2013; 39(5): 530-5.