Differences in C-Reactive Protein (CRP) Value Before and After Eradication Therapy of Helicobacter Pilory Gastritis in Children Siska Octaviani Purba 1 , Supriatmo 1 , Aridamuriany D. Lubis 1 1 Departement of Child Health, Faculty of Medicine, Universitas Sumatera Utara, Medan, Indonesia Abstract This study aimed to determine the difference CRP values before and after eradication therapy of Helicobacter pylori gastritis in children. A quasi-experimental study with a separate sample pretest-posttest design was carried out by collecting medical records of children aged 2-18 years diagnosed with H. pylori gastritis from October-December 2020. Data on serum CRP levels before and after H. pylori gastritis eradication therapy were collected from patient medical records. Comparison between groups of H. Pylori gastritis before and after eradication therapy was performed using T-dependent/Wilcoxon test. Test the normality using the Saphiro-Wilk test. There were 37 data that met the inclusion and exclusion criteria. The CRP value in children with H. pylori infection (+) before eradication therapy was 19.31 mg/dL (10.05-128). After giving eradication therapy, the value of CRP decreased to 11.2 mg/dL (6.8-30.4). Using the Wilcoxon test showed that there was a significant difference in CRP values between before and after eradication therapy (p < 0.001). There was a significant difference in CRP values between before and after H. pylori eradication therapy in children. Keywords: h. pylori, c-reactive protein, eradication therapy 1. Introduction Helicobacter pylori (H. pylori) infection usually begins in childhood, generally before the age of 5 years, then continues throughout life, and causes severe diseases such as gastritis, gastric ulcers, gastric carcinoma, and duodenal ulcers in adulthood. H. pylori has been recognized as a gastric pathogen infecting more than half of the world's population (Razavi et al,2015). This infection causes a low but chronic inflammatory response in the gastric and duodenal mucosa, which can last a lifetime if left untreated. Early diagnosis and treatment can prevent H. pylori-associated complications (Yang et al, 2019). Helicobacter pylori commonly colonizes the human gastric mucosa. It is estimated that 50% of the world's population may be infected, and the prevalence is higher in the population of low-income countries, ranging from 65% in adults from Thailand and Ethiopia, to 85% in mothers in Bangladesh. The prevalence of H. pylori in Bangladesh ranges from 47% in children under 2 years of age, 60% in children less than 5 years, to 93% prevalence in children under 15 years of age (Buerkli et al, 2000). The characteristics of H pylori infection in children are different from adults. Most children infected with H pylori remain asymptomatic, but develop chronic superficial gastritis, and a small percentage develop duodenal ulcers in late childhood or adolescence. Lymphoma of the lymphoid mucosal tissue and gastric ulcer are rare in children. Stomach cancer (adenocarcinoma) mainly develops in adults (Dror etal, 2016). C-reactive protein (CRP) is an acute-phase protein, originally named after its ability to precipitate c- polysaccharides from Streptococcus pneumoniae. The acute phase response consists of non-specific physiological responses and biochemical responses to most forms of tissue damage, infection, and inflammation. It is now widely used as a recognized marker for diagnosing and monitoring infections, especially in secondary health care. But now it is also increasingly being used by doctors in primary health care in identifying patients who may not respond to antibiotics. Thus, CRP has great potential as a useful tool to promote the correct use of antibiotics (Cals et al, 2018) In recent guidelines, the recommended pediatric protocol for H pylori eradication should consist of a combination of a proton pump inhibitor (PPI) and two high-dose antimicrobial agents, prescribed for 2 weeks. Treatment success should be more than 90% for each protocol analysis in preventing secondary antimicrobial resistance, reducing expensive procedures, and risky procedures required in advanced treatment. This number is rarely described in pediatric studies because of the high rate of antibiotic resistance against H pylori. The 152 www.ijrp.org IJRP 2021, 83(1), 152-157; doi:.10.47119/IJRP100831820212204