Non-Nuclear and Rare Nuclear ANA Patterns in Indirect Immunoflourescence Testing and their Clinical Associations
Objectives: A standardized nomenclature to report Antinuclear antibody(ANA) is given by the International consensus on ANA pattern (ICAP). The cytoplasmic, mitotic and rare nuclear patterns are infrequently reported.The study was done to understand the clinical significance and frequency of these unconventional patterns in our population.
Methods: Retrospective one year blinded study of ANA patterns in serum samples.
Results: Of the 4730 samples, 4568 were included after deleting 162 repeat samples. ANA positivity was seen in 673 cases (14.7%). Cytoplasmic patterns were found in 184 cases (27.3%) and mitotic pattern in 16 (2.4%) cases. Exclusive cytoplasmic patterns were seen in 100 cases (14.3%) and exclusive mitotic pattern in 14 cases (2.08%). Rare nuclear patterns were seen in 30 cases (4.5%).The most common exclusive cytoplasmic pattern was filamentous(n=39), whereas the common cytoplasmic pattern associated with nuclear pattern (mixed pattern) was cytoplasmic homogeneous (AC19). The rare nuclear patterns included Topo-I (n=9), nuclear envelope (n=5), multiple (n=6) and few (n=8) nuclear dots. While some of the common cytoplasmic patterns like filamentous and homogeneous were more frequent in AIDs the uncommon patterns showed varied clinical associations.
Conclusion: The study demonstrates the clinical significance of reporting exclusive and mixed non nuclear ANA patterns on IIF as many of these have known autoimmune associations.
1. Kumar Y, Bhatia A, Minz RW. Antinuclear antibodies and their detection methods in diagnosis of connective tissue diseases: a journey revisited. Diagn Pathol 2009;4:1.
2. Meroni PL, Schur PH. ANA screening: an old test with new recommendations. Ann Rheum Dis 2010;69:1420–2.
3. Chan EKL, von Mühlen CA, Fritzler MJ, Damoiseaux J, InfantinoM, Klotz W, et al; ICAP Committee. The International Consensus on ANA patterns (ICAP) in 2021-The 6th workshop and current perspectives. J Appl Lab Med 2022;7:322–30.
4. Damoiseaux J, von Mühlen CA, Garcia-De La Torre I, Carballo OG, de Melo Cruvinel W, et al. International consensus on ANA patterns (ICAP): the bumpy road towards a consensus on reporting ANA results. Auto Immun Highlights 2016;7:1.
5. Li QZ, Karp DR, Quan J, Branch VK, Zhou J, Lian Y, et al. Risk factors for ANA positivity in healthy persons. Arthritis Res Ther 2011;13:R38.
6. Rao JS, Shobha V, Thomas T, Kini U. Standardizing initial dilution titers of antinuclear antibodies for the screening of systemic lupus erythematosus. Indian J Rheumatol 2019;14:211– 7.
7. Bossuyt X, De Langhe E, Borghi MO, Meroni PL. Understanding and interpreting antinuclear antibody tests in systemic rheumatic diseases. Nat Rev Rheumatol 2020;16:715–26.
8. Chan EKL, de Melo CruvinelW, Andrade LEC. The international consensus on standardized nomenclature of antinuclear antibody HEp-2 cell patterns (ICAP) initiative - Current state and perspectives. In: Conrad K, Chan EKL, Andrade LEC, Steiner G, Pruijn GJM, Shoenfeld Y, editors. Autoantibody Research to Standardized Diagnostic Assays in the Management of Human Diseases series. Report on the 12th Dresden Symposium on Autoantibodies. Germany; 2015. p. 282–8.
9. Tebo AE. Recent approaches to optimize laboratory assessment of antinuclear antibodies. Clin Vaccine Immunol 2017;24:e00270–17.
10. Minz RW, Kumar Y, Anand S, Singh S, Bamberi P, Verma S, et al. Antinuclear antibody positive autoimmune disorders in North India: an appraisal. Rheumatol Int 2012;32:2883–8.
11. Guo YP, Wang CG, Liu X, Huang YQ, Guo DL, Jing XZ, et al. The prevalence of antinuclear antibodies in the general population of China: a cross-sectional study. Curr Ther Res Clin Exp 2014;76:116–9.
12. Chhabra S, Kumar Y, Kumar M, Sharma A, Bhardwaj R, Minz RW. Prevalence of autoantibodies to cellular cytoplasmic and mitotic antigens in routine antinuclear antibody reporting: Implementation of international consensus on antinuclear antibodies patterns guidelines. Indian J Rheumatol 2021;16:83–8.
13. Becker Y, Loignon RC, Julien AS, Marcoux G, Allaeys I, Lévesque T, et al. Anti-mitochondrial autoantibodies in systemic lupus erythematosus and their association with disease manifestations. Sci Rep 2019;9:4530.
14. Bhanji RA, Eystathioy T, Chan EK, Bloch DB, Fritzler MJ. Clinical and serological features of patients with autoantibodies to GW/P bodies. Clin Immunol 2007;125:247–56.
15. Zachou K, Oikonomou K, Renaudineau Y, Chauveau A, Gatselis N, Youinou P, et al. Anti-α actinin antibodies as new predictors of response to treatment in autoimmune hepatitis type 1. Aliment Pharmacol Ther 2012;35:116–25.
16. Irure-Ventura J, Rodríguez C, Vergara-Prieto E, Vargas ML, Quirant B, Jurado A, et al; GEAI and EASI groups. Rare immunofluorescence patterns of autoantibodies on HEp-2 cells defined by ICAP identify different autoimmune diseases in the absence of associated specificities: a Spanish multicentre study. Rheumatology (Oxford) 2021;60:3904–12.
17. Vermeersch P, Van den Bergh K, Blockmans D, Westhovens R, Bossuyt X. Anti-Golgi autoantibodies are not clinically associated with systemic autoimmune diseases. Ann Rheum Dis 2011;70:234–5.
18. Betancur JF, Londoño A, Estrada VE, Puerta SL, Osorno SM, Loaiza A, et al. Uncommon patterns of antinuclear antibodies recognizing mitotic spindle apparatus antigens and clinical associations. Medicine (Baltimore) 2018;97:e11727.
19. Sener AG. evaluation of rare antinuclear antibody patterns in a tertiary hospital in Izmir. J Basic Clin Health Sci 2018;2:53–7.
20. Nanda R, Gupta P, Patel S, Shah S, Mohapatra E. Uncommon antinuclear antibody patterns as diagnostic indicators. Clin Biochem 2021;90:28–33.
21. Alpini C, Lotzniker M, Valaperta S, Bottone MG, Malatesta M, Montanelli A, Merlini G. Characterization for anti-cytoplasmic antibodies specificity by morphological and molecular techniques. Autoimmun Highlights 2012;3:79–85.