Short-Term Infection Risk and Clinical Impact in Immune Thrombocytopenia After Treatment
Authors: Hu Ming Hung , Liu Chun-Yu , Tzeng Cheng-Hwai 
Published: October 2019

Abstract
Abstract 4652
Patient with refractory ITP have increased mortality compared with the normal population. Apart from major bleeding, infection was a major risk of death of these patients.1However, infections after diagnosis of immune thrombocytopenia are less addressed in the literature and its clinical impact on outcome of patients with ITP has not been well-addressed. This study aimed to characterize risk of infection events after diagnosis of ITP and its impact on outcome of these patients. We retrospectively evaluated 239 patients (109 men, 130 women; medium age: 63 yr) diagnosed between Jan 1, 1997 to Aug 31, 2011. Every patient received at least steroid treatment according to platelet count or bleeding symptoms after diagnosis. Infection event occurred in 59 patients (24.7%) within 6 months after diagnosis. Multivariate analysis revealed that age (>65 yr) was the most important risk factor regarding to infection (p=0.048, 95% CI 1.005 to 4.007). 1-year mortality rate after ITP diagnosis was significantly higher in those patients with infection after steroid treatment (p<0.001). We conclude that elderly patients with ITP are more prone to infections which have negative impact on post-diagnosis 1 year survival.
Table 1. The Demographic and Clinical Characteristics of Patients With Immune Thrombocytopenia Patient characteristic All patients (n=239) Sex, no. of patients (%) Male 109 (45.6%) Female 130 (54.4%) Medium age, y 63.0 (18∼97) Medium follow-up period, months 19.08 (0.1∼155) Thrombocytopenia1 no. of patients (%) 195 (81.6%) Severe 44 (18.4%) Moderate 20 (8.4%) Evan's syndrome, no. of patients (%) 19 (7.9%) Splenectomy, no. of patients (%) 35 (14.6%) Comorbidity, no. of patients (%) 74 (31%) DM 12 (5%) HTN 8 (3.3%) CKD 12 (5%) CHF 8 (3.3%) CVA 96 (40.2%) COPD 59 (24.7%) Any 13 (5.4%) Infectious event, no. of patients (%) 11 (4.6%) Total patient 2 (0.8%) Mortality, no. of patients (%) Total numbers Death due to infection Death due to bleeding 1. Moderate thrombocytopenia= platelet counts between 30.0 × 109/L and 100.0 × 109/L; severe thrombocytopenia counts below 30.0 × 109/L.
Table 2. Clinical Characteristics of Infection Events Patient characteristic All events (n=70) Infectious event, no. (%) Total event 70 Pneumonia 31 (44.2%) UTI 13 (15.6%) Herpes zoster 9 (12.8%) Cellulitis 7 (10.0%) Others1 10 (14.3%) Pathogens no. of event Events with definite cultured pathogen 29 Staphylococcus aureus 8 Klebsiella pneumonia 6 Yeast2 6 Pseudomonas aeruginosa 5 Acinetobacter baumannii 4 Stenotrophomonas maltophilia 4 E. coli 3 Enterobacter spp. 3 Others3 5 Infection event date 1st month 23 (32.9%) 2nd month 17 (24.3%) 3rd month 7 (10.0%) 4th month 8 (11.4%) 5th month 6 (8.5%) 6th month 9 (12.9%) 1. Other infection includes oral candidiasis (2), cholangitis (1), fungemia (1), bacteremia (1), intraabdominal abscess (1), facial abscess (1), osteomyelitis (1), pseudomembranous colitis (1), acute suppprative periodontitis (1). 2. Including Candida albicans and Aspergillus. 3. Other pathogen including Streptococcus agalactiae (1), Serratia spp (1) Clostridium dificile (1), Chryseobacterium meningosepticum (1), gram positive cocci (1).
Table 3. Baseline Characteristics of Patients with or without Infection Character No infection (n=180) Infection (n=59) p value Sex 0.006* M 73 (40.6%) 36 (61.0%) F 107 (59.4%) 23 (39.0%) Age 0.616 Medium 57 73 Range 18∼90 23∼97 Thrombocytopenia 0.268 Moderate 36 (20.0%) 8 (13.6%) Severe 144 (80.0%) 51 (86.4%) Evan's syndrome 14 (7.8%) 6 (10.2%) 0.565 Splenectomy 13 (7.2%) 6 (10.2%) 0.468 Cormobidity DM 21 (11.7%) 14 (23.7%) 0.023* HTN 51 (28.3%) 23 (39.0%) 0.125 CKD 6 (3.3%) 6 (10.2%) 0.037* CHF 5 (2.8%) 3 (5.1%) 0.393 CVA 8 (4.4%) 4 (6.8%) 0.476 COPD 4 (2.2%) 4 (6.8%) 0.095 Any 64 (35.8%) 31 (52.5%) 0.022* ANC<1000 49 (27.2%) 26 (44.1%) 0.016* Response1 0.001* CR+PR 151 (83.9%) 38 (64.4%) NR 29 (16.1%) 21 (35.6%) 1. Response: complete response (CR) partial response (PR) no response (NR).
Table 4. Multivariate Analysis for the Short Term (Within 6 Months) Infection Risk in Patient with ITP Dependant variable Odds ratio P value 95% confidence interval Lower bound Upper bound Age >65 2.205 0.048* 1.005 4.077 ALC<1000 1.807 0.066 0.961 3.399 Any cormobidity 1.374 0.357 0.699 2.699

Disclosures:
No relevant conflicts of interest to declare.