C:\Users\UNIVERSA MEDICINA\Docu 71 ABSTRACT UNIVERSA MEDICINA Neutrophil-lymphocyte ratio and Fournier gangrene severity index are not prognostic factors of mortality in fournier gangrene patients Muhammad Achdiar Raizandha1,2, Furqan Hidayatullah1,2, Yudhistira Pradnyan Kloping1,2, and Fikri Rizaldi1,3* BACKGROUND Fournier gangrene (FG) is a life-threatening disease, commonly found in diabetic and immunocompromised patients. Recent studies suggested the use of new parameters apart from the commonly used Fournier gangrene severity index (FGSI), such as the neutrophil-lymphocyte ratio (NLR), the clinical use of which remains questionable. Therefore, we aimed to evaluate the role of the NLR and FGSI as a prognostic factor of mortality in patients with FG. METHODS This is an analytical study with a retrospective approach involving 109 adult patients diagnosed with FG. Data were collected regarding medical history, symptoms, physical examination findings, and laboratory tests. The FGSI score and NLR were determined. Bivariate analysis was performed using chi-square test and independent t-test. Overall survival between groups was compared using Kaplan–Meier survival estimates and Cox regression test. RESULTS Of the 109 patients, 90 survived (82.5%, group 1) and 19 died (17.43%, group 2). The cut-off point of NLR among the patients was 10.9, with a 73.7% sensitivity and 60% specificity. The area under curve value was 0.65 (95% CI; 0.524-0.754; p<0.05). The Kaplan Meier survival analysis showed that NLR was as an independent prognostic factor of mortality in FG patients (HR 5.177; 95% CI; 1.092-8.471; p<0.05), but Cox regression analysis showed that NLR and FGSI were not significant prognostic factors of mortality (p=0.09 and p=0.179; respectively). CONCLUSION This study demonstrated that NLR and FGSI are not important as prognostic tools for FG mortality. Keywords: Fournier gangrene, prognostic factor, neutrophil, lymphocyte, neutrophil-lymphocyte ratio ORIGINAL ARTICLE pISSN: 1907-3062 / eISSN: 2407-2230 DOI: http://dx.doi.org/10.18051/UnivMed.2022.v41.71-78 Copyright@Author(s) - Available online at https://univmed.org/ejurnal/index.php/medicina/article/view/1263 January-April, 2022 Vol.41- No.1 1Department of Urology, Faculty of Medicine, Universitas Airlangga, Surabaya, East Java, Indonesia 2Department of Urology, Dr. Soetomo General Academic Hospital, Surabaya, East Java, Indonesia 3Department of Urology, Universitas Airlangga Teaching Hospital, Surabaya, East Java, Indonesia *Correspondence: Fikri Rizaldi Department of Urology, Universitas Airlangga Teaching Hospital, Surabaya, East Java, Indonesia Phone/fax: (031)-5916290 Email: fikririz@gmail.com ORCID ID: 0000-0002-4588-6584 Date of first submission, December 9, 2021 Date of final revised submission, March 30, 2022 Date of acceptance, April 9, 2022 This open access article is distributed under a Creative Commons Attribution- Non Commercial-Share Alike 4.0 International License Cit e th is ar ticle as: Ra iza ndh a M A, Hidayatullah F, Kloping YP, Rizald F. Neutrophil-lymphocyte rat io a nd Fournier gangrene severity index are not prognostic factors of mortality in fournier gangrene patient. Univ Med 2022;41:71- 78. doi: 10.18051/UnivMed.2022.v41. 71- 78 72 Raizandha, Hidayatullah, Kloping, et al Neutrophil-lymphocyte ratio of FG patients INTRODUCTION Fournier gangrene (FG) is a rare type of necrotizing fasciitis that affects the perineal, genital, or anorectal region. It is characterized by widespread soft tissue necrosis and systemic toxicity of the superficial fascia and subcutaneous tissues.(1) Even though it is quite uncommon, constituting only 0.02% of all hospital admissions, it is considered a urological emergency as it has a high mortality rate, at 20 to 50% in most reported series.(2,3) In recent years, the incidence of Fournier gangrene is increasing with the increase in diabetes prevalence and the number of immunocompromised patients due to various causes.(4) Previous studies have determined the possible risk factors for predicting the prognosis of Fournier ga ngr ene patie nts, such as comorbidities, Fournier gangrene severity index (FGSI) score and disease severity. ( 5– 7 ) Parameters to determine the severity and prognosis of the disease have been suggested, one of which is the FGSI, commonly used to assess the severity of the disease by evaluating clinical and laboratory parameters, such as temperature, heart rate, respiratory rate, serum sodium, serum potassium, serum creatinine, serum bicarbonate, hematocrit and white blood cell count.(8) Since its introduction, the score has been validated by many studies, but its accuracy remains questionable.(9,10) Nevertheless, it is the only well-known tool to assess severity.(10) Recent findings have suggested simple and promising parameters by utilizing normal laboratory findings. There is an increasing interest in predicting the prognosis of the patients with a simple blood test since studies began suggesting a correlation between inf lammatory status and disease prognosis. One of the most commonly used parameter is the neutrophil-lymphocyte ratio (NLR).(11) Findings regarding its potential use in predicting the prognosis of Fournier gangrene patients have been reported. A retrospective study showed that the FGSI scoring system was not associated with determining poor prognosis. However, high NLR and high platelet to lymphocyte ratio (PLR) were associated with predictors of mortality in patients with Fournier’s gangrene.(10) In contrast, another retrospective observational analytical study of patients diagnosed with Fournier fasciitis (FF) showed that FF severity, as measured by NLR and PLR, does not correspond to the severity measured by the FGSI.(12) Other studies utilized the NLR cutoff- values of 13.71 (sensitivity 83.3% and specificity 86.6%) (13) and 8 (sensitivity 72.2%, specificity of 52.3%), respectively.(14) The present study included FGSI in the analysis of NLR as mortality predictors. Therefore, the aim of this study was to determine the role of NLR and FGSI as prognostic factors of mortality in patients with FG. METHODS Research design Thi s wa s an ana lytic al s tudy with a prospective approach utilizing secondary data taken from the medical records of Dr. Soetomo General-Academic Hospital from January 2012 to November 2020. Research subjects Fournier gangrene was defined as an acute necrotic infection involving the scrotum, penis or perineum. A total of 109 adult patients aged 18 and above with Fournier gangrene or fasciitis necroticans and complete laboratory examination data including neutrophil and lymphocyte counts were included in the study. Patients with a history of malignancy or chemoradiation were excluded, as were also those with incomplete or unclear data in the medical records. Data collection The data collected and presented included p a t i e nt a ge , d i a gno s is , l e s i o n l oc a t i o n, comorbidities, FGSI, bacterial culture results, surgical interventions, and survival status. Statistical analysis The collected data were grouped and displayed descriptively in the form of tables and 73 narratives. Bivariate analysis was performed using chi-square test and independent t-test. The association between the binary marker of NLR and the risk of mortality was evaluated using a survival curve. Mortality was defined as disease related death during the hospital stay and survival was measured in days. The separation between the curves of patients with a high NLR and those with a low NLR indicated the prognostic ability o f th e ma r ke r re pr es e nt ed by a r e c ei ve r operating characteristic (ROC) curve.(15) The performance of the marker was evaluated by the area under the curve (AUC), which is a measure of the ability of a tool to discriminate whether a condition is present or not. An AUC value of 0.5 indicates that the test has no discriminating ability, whereas an AUC of 1.0 indicates perfect discrimination.(16) Overall survival was compared between groups using Kapla n–Meier survival estimates and the pr oportional-hazards Cox regression. The statistical significance was set at p<0.05 for all analyses. Ethical clearance The ethical committee of the research and development center of Dr. Soetomo General Academic Hospital approved this study under number 0725/109/4/V/2021. RESULTS Baseline characteristics A total of 109 patients with mean age of 50.31 ± 14.75 years had mean NLR of 15.86 ± 12.75. Only 25 patients had an FGSI score of more than 9. The scrotal area was the most commonly af fected a rea ( n= 55, 50. 46%) compared to other areas. Most patients also suffered from diabetes mellitus (n=40, 36.7%) l e a d i ng t o i n f e c t i o ns c a us e d ma in l y b y Pseudomonas aeruginosa ( n=23, 21.1%), Klebsiella pneumoniae (n=21, 19.27%, and Acinetobacter baumannii (n=20, 18.35%). Most patients were treated with debridement and necrotomy, followed by incision and drainage of the abscess (n=55, 50.46%), after which most p a t i e nt s s u r vi ve d ( n = 9 0, 82.5 7 % ) . T he differences in clinical parameters between the survivors and non-survivors are shown in Table 2. The FGSI scores in the two groups did not show significant differences (p=0.248), but the NLR did show significant differences between the two groups (p=0.021) (Table 2). NLR and FGSI value as a prognostic marker In this study, the NLR cut-off point among the patients was 10.9, with 73.7 % sensitivity and 60 % specificity, as shown in Figure 1. The AUC was 0.65 (95% CI; 0.524-0.754; p<0.05). The Kaplan-Meier curve in Figure 2 shows that the NLR cut-off value of 10.9 has a significant impact on the patient’s mortality rate (95% CI; 29.7-19.7; p<0.05). The univariate Kaplan Meier survival analysis indicated that NLR can be used as an independent predictor for mortality in Fournier gangrene patients (HR 5.177; 95% CI; 1.092-8.471; p<0.05). However, the Cox regression showed that NLR and FGSI score were not significant as a prognostic factor of mortality in FG patients (the p values of NLR a n d FG SI we r e p= 0 . 09 a n d p = 0. 17 9 ; respectively) (Table 3). DISCUSSION Fournier gangrene is a rare and serious c o nd i t i on t h a t c a n be f o un d i n immunocompromised patients.(17) Even though FGSI has been validated in numerous studies, it s us e in cl in ica l se tt ings is of te nt imes questionable. There is still a high mortality rate ranging from 20 to 50% among Fournier gangrene patients due to sepsis,(17) which is one of the main causes of mortality and extended length of stay in patients with urological infections, including Fournier gangrene.(18) To reduce the severity of the disease, the utilization of inexpensive and simple laboratory parameters, such as white blood cell parameters, erythrocyte sedimentation rate, and C-reactive protein, are necessary.(19,20) The use of NLR as a parameter Univ Med Vol. 41 No 1 74 Raizandha, Hidayatullah, Kloping, et al Neutrophil-lymphocyte ratio of FG patients C Variables n (%) Age (years) 50.31 ± 14.79 NLR 15.86 ± 12.75 FGSI > 9 25 (23.0) < 9 84 (70.0) Diagnosis Fournier gangrene 53 (48.62) Fournier gangrene and perianal abscess 33 (30.28) Fournier gangrene and scrotal abscess 22 (20.18) Fournier gangrene and perianal fistula 1 (0.92) Affected Region Penoscrotal 12 (11.01) Penoscrotal and perianal 2 (1.83) Penoscrotal and suprapubic 2 (1.83) Perianal 27 (24.77) Perianal and scrotum 8 (7.34) Scrotum 55 (50.46) > 2 regions 3 (2.75) Comorbidities Diabetes mellitus 40 (36.70) Diabetes mellitus and hypertension 21 (19.27) Diabetes mellitus and chronic kidney disease 7 (6.42) Diabetes mellitus and hepatitis B infection 1 (0.92) Hypertension 8 (7.34) Chronic Kidney Disease 4 (3.67) No comorbidities 28 (25.67) Bacterial culture Pseudomonas aeruginosa 23 (21.10) Klebsiella pneumoniae 21 (19.27) Staphylococcus epidermidis 12 (11.01) Acinetobacter baumannii 20 (18.35) Gemella morbillorum 2 (1.83) Escherichia coli 13 (11.93) Candida spp 8 (7.34) Clostridium perfringens 5 (4.59) Fusobacterium necrophorum 5 (4.59) Survival intervention Debridement-necrotomy 48 (44.04) Debridement-necrotomy and incision-drainage 55 (50.46) Debridement-necrotomy and graft 3 (2.75) Debridement-necrotomy and urinary diversion 3 (2.75) Survival status Survived 90 (82.57) Dead 19 (17.43) Table 1. Characteristics and clinical features of the subjects (n=109) Data presented as n (%), except for age and NLR (mean ± SD); NLR: Neutrophil-to-lymphocyte ratio; FGSI: Fournier Gangrene Severity Index has been suggested by many studies. Kaushik et al.(21) recommended its use as a diagnostic marker and predictor in septic patients. Its greatest strengths are its efficiency in time, cost, and application compared to other examinations. Neutrophils are one of the main immune cells against pathogens and their crucial function is to produce enzymes during the acute inflammatory phase. Neutrophils are able to lyse infected cells, produce free radicals, and induce the production 75 Univ Med Vol. 41 No 1 of pro-inflammatory cytokines. (2 2) T he coordination of the transition from innate to adaptive immunity is handled by the lymphocytes. Both innate and adaptive immunity are core components of the body’s immune system against pathogens.(23) The ratio of the neutrophil and lymphocyte numbers indicates a transition between innate and adaptive immunity. The relatively low number of lymphocytes could cause a cytokine storm and severe inflammation, leading to a worse prognosis. Our study showed the potential role of NLR as a prognostic marker for Fournier gangrene patients, since patients with a high NLR had a 5.17-times greater risk of mortality than those with a low NLR. This finding is in line with the study by George et al. in 2020 who discovered a significant difference in NLR among septic patients with multiple organ dysfunction syndrome (MODS). They found that most septic patients with MODS had a high NLR. The NLR is deemed superior to a white blood cell count.(24) A study with a large sample size conducted by Li et al.(25) also showed the predictive capability of NLR in septic patients. However, a study by Ni et al.(26) suggested that NLR does not significantly predict septic inpatients with a long hospital stay. T he difference between these findings may have been caused by other factors in these studies which could affect the patients’ NLR. The increased NLR in septic patients is difficult to use as a predictive tool, considering that there are many factors affecting neutrophil and lymphocyte counts. However, it can still be used as a mortality predictor in septic patients. The ROC curve, Kaplan-Meier, and hazard ratio findings in this study are in line with those of the study by Yim et al.(10) which suggested that NLR is a useful independent predictor that is associated with increased mortality in FG patients. In our study, Cox regression showed that NLR and FGSI score had no significant prognostic value for mortality in FG patients. Another study showed that the FGSI scoring system was not found to be valuable in determining prognosis, but that the NLR and PLR were valuable.(27) One other study showed similar results, in that the FGSI scoring system was not associated with determining poor prognosis, but that high NLR and high PLR were associated with predictors of mortality in patients with FG. (10) In our study, a high FGSI score (>9) was generally associated with the non-surviving group; however, multivariable Cox regression analyses found this not to be statistically significant. Variables Survivors (n=90) Non-survivors (n=19) p value Age (years) 49 ± 14.9 54 ± 13.8 0.208 FGSI ≤ 9 >9 75 (89.3) 17 (68.0) 9 (10.7) 8 (32.0) 0.248 NLR ≤10.9 >10.9 52 (91.2) 38 (73.1) 5 (8.8) 14 (16.9) 0.021 Table 2. Differences in clinical parameters between the survivors and non-survivors Data presented as n (%), except for age mean ± SD; NLR: Neutrophil-to-lymphocyte ratio; FGSI: Fournier Gangrene Severity Index Variables Coefficient Hazard Ratio p value Age (years) FGSI score NLR 0.017 0.081 -0.033 1.017 1.328 2.043 0.356 0.179 0.09 Table 3. Multivariate Cox regression analysis NLR: Neutrophil-to-lymphocyte ratio; FGSI: Fournier Gangrene Severity Index 76 Raizandha, Hidayatullah, Kloping, et al Neutrophil-lymphocyte ratio of FG patients Figure 1. Receiver operator characteristic curve for neutrophil to lymphocyte ratio (NLR), area under the curve = 0.65 (95% CI; 0.524-0.754; p<0.05, sensitivity = 73.7, specificity = 60.0 Figure 2. Kaplan-Meier survival curves for the overall survival indicating the value of NLR as a survival predictor 77 Univ Med Vol. 41 No 1 T he p r e s e n t st u dy is l i mi t e d b y i t s retrospective design and use of secondary data. Most samples included in this study had a high NLR ratio, indicating that most included patients were classified as severe. The inclusion of more patients with different disease severity should be performed in future studies. This study showed the utility of the NLR in FG. The NLR can be examined with high availability and low cost. This marker could be an ideal and simple biomarker to predict the outcome of mortality in patients with FG. CONCLUSIONS This study demonstrated that a high NLR and FGSI cannot be used as an indicator of poor prognosis of mortality in FG patients. CONFLICT OF INTEREST The authors declare no conflicts of interest. ACKNOWLEDGMENTS The authors thank the medical record staff of Dr. Soetomo General-Academic Hospital for their kind cooperation. CONTRIBUTORS MAR, FH, YPK contributed to concept and design; MAR, FH contributed to data collection and analysis. MAR and FR contributed to writing manuscript and critical review. All authors have read and approved the final manuscript. REFERENCES 1. Voelzke BB, Hagedorn JC. Presentation and diagnosis of Fournier gangrene. Urology 2018;114:8–13. doi: 10.1016/j.urology.2017.10.031. 2. Auerbach J, Bornstein K, Ramzy M, Cabrera J, Montrief T, Long B. Fournier gangrene in the emergency department: Diagnostic dilemmas, treatments and current perspectives. Open Access Emerg Med 2020;12:353. doi: 10.2147/ OAEM.S238699. 3. Montrief T, Long B, Koyfman A, Auerbach J. Fournier gangrene: a review for emergency clinicians. J Emerg Med 2019;57:488–500. doi: 10.1016/j.jemermed.2019.06.023. 4. Chernyadyev SA, Ufimtseva MA, Vishnevskaya IF, et al. Fournier’s gangrene: literature review and clinical cases. Urol Int 2018;101:91–7. https:// doi.org/10.1159/000490108. 5. Pehlivanlý F, Aydin O. Factors affecting mortality in Fournier gangrene: a single center experience. Surg Infect (Larchmt) 2019;20:78–82. doi: 10.1089/ sur.2018.208. 6. Hahn HM, Jeong KS, Park DH, Park MC, Lee IJ. Analysis of prognostic factors affecting poor outcomes in 41 cases of Fournier gangrene. Ann Surg Treat Res 2018;95:324-32. doi: 10.4174/ astr.2018.95.6.324. 7. Morais H, Neves J, Ribeiro HM, et al. Case series of Fournier’s gangrene: affected body surface area–The underestimated prognostic factor. Ann Med Surg (Lond) 2017;16:19–22. doi: 10.1016/ j.amsu.2017.02.043. 8. Hong KS, Yi HJ, Lee R, Kim KH, Chung SS. Prognostic factors and treatment outcomes for patients with Fournier’s gangrene: a retrospective study. Int Wound J 2017;14:1352–8. DOI: 10.1111/ iwj.12812. 9. Arora A, Rege S, Surpam S, Gothwal K, Narwade A. Predicting mortality in Fournier gangrene and validating the Fournier gangrene severity index: our experience with 50 patients in a tertiary Care Center in India Urol Int 2019;102:311–8. doi: 10.1159/000495144. 10. Yim SU, Kim SW, Ahn JH, et al. Neutrophil to lymphocyte and platelet to lymphocyte ratios are more effective than the Fournier’s gangrene severity index for predicting poor prognosis in Fournier’s gangrene. Surg Infect (Larchmt) 2016;17:217–23. DOI: 10.1089/sur.2015.126. 11. Lee JS, Kim NY, Na SH, Youn YH, Shin CS. Reference values of neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio, platelet-lymphocyte ratio, and mean platelet volume in healthy adults in South Korea. Medicine (Baltimore) 2018;97: e11138. doi: 10.1097/MD.0000000000011138. 12. Guemes-Quinto A, Godínez-Vidal AR, Villanueva- Herrero JA, et al. Usefulness of neutrophil-to- lymphocyte ratio and platelet-to-lymphocyte ratio as predictors of severity on Fournier fasciitis of the Hospital General de México "Dr. Eduardo Liceaga." Rev Med Hosp Gen Mex 2019;82:17 5-8. https://doi.org/10.24875/ hgmx.m19000027. 13. Demir CY, Yuzkat N, Ozsular Y, Kocak OF, Soyalp C, Demirkiran H. Fournier gangrene: association of mortality with the complete blood count 78 Raizandha, Hidayatullah, Kloping, et al Neutrophil-lymphocyte ratio of FG patients parameters. Plast Reconstr Surg 2018;142:68e- 75e. doi: 10.1097/PRS.0000000000004516. 14. Özlülerden Y, Ba?er A, Çelen S, ALKI? O. Can we predict poor prognosis in Fournier gangrene? J Surg Med 2020;4:1157-60. https://doi.org/ 10.28982/josam.826917. 15. Combescure C, Perneger T V, Weber DC, Daurès J-P, Foucher Y. Prognostic ROC curves: a method for representing the overall discriminative capacity of binary markers with right-censored time-to-event endpoints. Epidemiology 2014;103- 9. doi: 10.1097/EDE.0000000000000004. 16. Doluo?lu ÖG, Karagöz MA, K?l?nç MF, et al. Overview of different scoring systems in four nie r's ga ngr ene and a sse ssment o f prognostic factors. Turk Urol Derg 2016;42:190- 6. doi: 10.5152/tud.2016.14194. 17. Benjelloun EB, Souiki T, Yakla N, et al. Fournier's gangrene: our experience with 50 patients and analysis of factors affecting mortality. World J Emerg Surg 2013;8:13. doi: 10.1186/1749-7922-8- 13. 18. Abou Dagher G, Hajjar K, Khoury C, et al. Outcomes of patients with systolic heart failure pr esenting with se psis to the eme rgency department of a tertiary hospital: a retrospective chart review study from Lebanon. BMJ Open 2018;8:e022185. doi: 10.1136/bmjopen-2018- 022185. 19. Dal-Pizzol F, Ritter C. À procura do Santo Graal: aonde vamos com os biomarcadores na sepse? Rev Bras Ter Intensiva 2012;24:117-8. ohttps:// doi.org/10.1590/S0103-507X2012000200004. 20. Lora-Andosilla M, Cantillo-García K, Borré- Naranjo D, Buelvas-Villalba M, Ortiz-Ruiz G, Dueñas-Castell C. Biomarkers in sepsis. In: Ortiz- Ruiz G, Dueñas-Castell C, editors. Sepsis. 3rd ed. New York: Springer-Verlag;2018. p. 39-50. 21. Kaushik R, Gupta M, Sharma M, et al. Diagnostic and prognostic role of neutrophil-to-lymphocyte ratio in early and late phase of sepsis. Indian J Crit Care Med 2018;22:660-3. doi: 10.4103/ ijccm.IJCCM_59_18. 22. Wang J, Arase H. Regulation of immune responses by neutrophils. Ann N Y Acad Sci 2014;1319:66-81. doi: 10.1111/nyas.12445. 23. Moro-García MA, Mayo JC, Sainz RM, Alonso- Arias R. Influence of inflammation in the process of T lymphocyte differentiation: proliferative, metabolic, and oxidative changes. Front Immunol 2 01 8 ;9 :33 9 . http s://do i.o r g/1 0 .3 3 89/ fimmu.2018.00339. 24. George AA, Thomas TP, Gaffoor A. The role of neutrophil/lymphocyte ratio in predicting the severity of sepsis in a tertiary care hospital in South India: a retrospective study. Int J Res Med Sci 2020;8:1624-8. DOI: http://dx.doi.org/ 10.18203/2320-6012.ijrms20201490. 25. Li MX, Liu XM, Zhang XF, et al. Prognostic role of neutrophil-to-lymphocyte ratio in colorectal cancer: a systematic review and meta-analysis. Int J Cancer 2014;134:2403-13. doi: 10.1002/ ijc.28536. 26. Ni J, Wang H, Li Y, Shu Y, Liu Y. Neutrophil to lymphocyte ratio (NLR) as a prognostic marker for in-hospital mortality of patients with sepsis: A secondary analysis based on a single-center, r etrosp ec tive , c oho rt study. Me dic ine (Baltimore) 2019;98:e18029. doi: 10.1097/ MD.0000000000018029. 27. Kahramanca S, Kaya O, Özgehan G, et al. Are neutrophil-lymphocyte ratio and platelet- lymphocyte ratio as effective as Fournier's gangrene severity index for predicting the number of debridements in Fourner's gangrene? Ulus Travma Acil Cerrahi Derg 2014 ;20:107-12. doi: 10.5505/tjtes.2014.62829.