Xanthogranulomatous Pyelonephritis: Case Report.

BACKGROUND: In the emergency department (ED), pyelonephritis is a fairly common diagnosis, especially in patients with unilateral flank pain. Xanthogranulomatous pyelonephritis (XGP) is a rare type of pyelonephritis that is associated with unique features, which may lead to its diagnosis. CASE REPORT: A 30-year-old male patient presented to the ED for evaluation of right-sided abdominal pain that has been ongoing for the past 24 hours. He noted the pain was located predominantly in the right flank and described it as sharp in nature. The pain was nonradiating and was associated with scant hematuria. He stated that he had similar pains approximately 1 month earlier that resolved after a few days. The patient underwent a bedside ultrasound and a subsequent computed tomography (CT) scan of the abdomen and pelvis, which showed an enlarged, multiloculated right kidney with dilated calyces and a large staghorn calculus, findings that represent XGP. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report highlights an unusual variant of pyelonephritis, a relatively common ED diagnosis. XGP should be considered in patients with recurrent pyelonephritis, as treatment for XGP may require surgical intervention in addition to traditional antibiotic management.

Impact of timing of urinary drainage on clinical outcomes in patients with obstructive pyelonephritis associated with upper urinary tract stones: a propensity score-matched analysis.

OBJECTIVE: We aimed to assess the impact of the timing of urinary drainage on clinical outcomes in patients with obstructive pyelonephritis (OPN) associated with upper urinary tract (UUT) stones. METHODS: We retrospectively evaluated the multicenter dataset of 240 patients with OPN associated with UUT stones who underwent urinary drainage. We divided the patients into two groups depending on the timing of urinary drainage; emergency drainage, defined as within 12 h from admission, and delayed drainage, defined as between 12 and 48 h from admission. The outcomes were the length of hospital stay, time to leukocyte normalization, and time to body temperature normalization. One-to-two propensity score matching (PSM) was applied to minimize the effect of confounders between the two groups. Subsequently, predictive patient factors for emergency drainage were analyzed using the logistic regression model. RESULTS: Only the time from admission to normal body temperature was significantly shorter in the emergency drainage group when compared with the delayed drainage group (median: 2 vs. 3 days; p = 0.02), while there was no difference in time from drainage to body temperature normalization between the two groups. On multivariable analysis, high pretreatment C-reactive protein (CRP) was associated with implementing emergency drainage within 12 h. CONCLUSIONS: The timing of urinary drainage was only associated with the duration of high fever, but it did not affect the postdrainage course. Emergency urinary drainage is more likely to be performed in severe patients, such as high pretreatment CRP.

Wunderlich syndrome in a patient with pyelonephritis.

An elderly female patient with left pyelonephritis developed worsening left flank pain, hypotension and a drop in haemoglobin (Hb) from 97 g/L to 67g/L on the third day of her admission. There was no recent trauma, history of coagulopathy or risk factors for renal malignancy or vascular disease.A contrasted CT scan of the kidneys revealed a 3.8 cm left renal subcapsular haematoma with no active contrast extravasation. Her atraumatic subcapsular haematoma fulfils two out of three clinical features of Lenk's triad (acute flank pain, hypovolaemic shock), suggestive of Wunderlich syndrome. Urine and blood cultures grew Klebsiella pneumoniae and she was managed conservatively with culture-directed antibiotics, fluids and blood products.Wunderlich syndrome is a rare complication of pyelonephritis and should be considered in patients with pyelonephritis who develop acute severe flank pain, Hb drop and haemodynamic instability. Appropriate medical and surgical therapies need to be instituted early to ensure good outcomes.

Emphysematous pyelonephritis with progression to necrotising fasciitis of the posterior cervical region and the retropharyngeal space.

A man in his 50s with diabetes presented with backache, left flank pain and fever. On evaluation, he was found to have emphysematous pyelonephritis of the left kidney with a paranephric abscess extending into the posterior abdominal wall and superiorly up to the posterior chest wall and inferiorly extending up to the posterior superior iliac spine. The management involved the initiation of broad-spectrum antibiotics and percutaneous drainage of the abscess. However, as he continued to worsen symptoms-wise, he underwent computed-enhanced CT of the abdomen and thorax. The imaging revealed the presence of a purulent collection in the left lumbar region with an extension along the posterior cervical region and the retropharyngeal space. He underwent a fasciotomy of the lumbar region. The occurrence of emphysematous pyelonephritis along with necrotising fasciitis is uncommon and requires early aggressive management with broad-spectrum antibiotics and adequate drainage. This emphasises the need for early reimaging if the patient does not settle with antibiotics or percutaneous drainage.

Renal abscess complicating acute pyelonephritis in children: Two cases report and literature review.

RATIONALE: To describe the diagnostic and treatment approaches of renal abscesses complicated with acute pyelonephritis in children. PATIENT CONCERNS: Two children presented with fever, vomiting, and abdominal pain with no typical manifestations, like frequent urination, urgency, dysuria, hematuria, foam urine, and lumbago. Renal abscess complicating acute pyelonephritis was diagnosed by B-ultrasound and computed tomography enhancement. Moreover, inflammatory markers were elevated significantly, but routine blood and urine cultures were repeatedly negative. The empirical anti-infection therapy had no obvious effect. A pathogenic diagnosis was confirmed in case two, and macro gene detection in blood and urine guided the follow-up treatment. DIAGNOSES: Both children were diagnosed with acute gastroenteritis on admission, but renal abscess complicating acute pyelonephritis were diagnosed by imaging examination. INTERVENTIONS: Both children were given anti-infection therapy of third-generation cephalosporin, which had no obvious effect. Routine blood and urine cultures were repeatedly negative. Case one was changed to piperacillin sodium tazobactam. We further carried out blood and urinary metagenomic next-generation sequencing detection for case two. Meanwhile, meropenem and linezolid anti-infection treatment was given. The results showed overlapping infection with Escherichia coli and Enterococcus faecalis. According to the genetic test results, amoxicillin clavulanate potassium combined with nitrofurantoin were prescribed after discharge. OUTCOMES: Clinical symptoms of the 2 children disappeared, the infection was controlled, and imaging showed that renal abscess complicated with acute pyelonephritis disappeared. LESSONS: The clinical spectrum of renal abscess complicating acute pyelonephritis is vague, with no specific manifestations, and can be easily misdiagnosed. B-ultrasound and computed tomography enhancement are helpful in making a definite diagnosis. Moreover, the sensitivity of routine culture is low, and metagenomic next-generation sequencing might be helpful to detect pathogenic microorganisms and guided treatment. Early treatment with broad-spectrum antibiotics might have favorable outcomes.

Particularities of Urinary Tract Infections in Diabetic Patients: A Concise Review.

Diabetes mellitus is a chronic disease that, untreated or poorly controlled, can lead to serious complications, reducing life expectancy and quality. Diabetic patients are more likely to develop infections, including many common infections, but also pathognomonic ones such as emphysematous pyelonephritis, malignant otitis externa, mucormycosis and Fournier's gangrene. Considering the fact that diabetic patients experience more frequently urinary tract infections (UTIs) with a worse prognosis than non-diabetic people, we conducted a review study based on data in the literature, following the particularities of UTIs in this group of patients, the risk factors, the mechanisms involved and the challenges in their management. The findings highlight that UTI in diabetic patients have some particularities, including a more frequent evolution to bacteremia, increased hospitalizations, and elevated rates of recurrence and mortality than non-diabetic patients. The possible risk factors identified seem to be female gender, pregnancy, older age, UTI in the previous six months, poor glycemic control and duration of diabetes. The mechanisms involved are related to glucosuria and bladder dysfunction, factors related to bacterial strains and host response. The bacterial strains involved in UTIs in diabetic patients and their antibiotic susceptibility profile are, with some exceptions, similar to those in non-diabetic people; however, the antimicrobial agents should be carefully chosen and the duration of the treatment should be as those required for a complicated UTI. The data related to the risk of developing UTIs in patients treated with SGLT-2 inhibitors, a new class of oral hypoglycaemic agents with cardiovascular and renal benefits, are controversial; overall, it was evidenced that UTIs occurred at the initiation of the treatment, recurrent infection was uncommon and the majority of UTIs responded to treatment with standard antibiotics. Moreover, interruption or discontinuation of SGLT-2 inhibitor as a result of UTI was rare and SGLT-2 inhibitors did not increase the risk of severe infections such as urosepsis and pyelonephritis.

A single-centre report of acute pyelonephritis in a patient after kidney transplantation - analyses of risk factors.

BACKGROUND: Urinary tract infections (UTI) are the most common infectious complications after kidney transplantation (KTx) with highest incidence in the first three months of transplantation. UTI in transplant recipients increase morbidity and mortality, risk of graft failure and incidence of acute rejection episodes. According to published data, urinary tract infections significantly affect graft survival. The aim of our study was to identify possible risk factors for the development of UTI. MATERIAL AND METHODS: We retrospectively analyzed a cohort of patients who received kidney transplantation between January 2014 and December 2016 in the Transplant Center of Louis Pasteur University Hospital in Kosice. One hundred and fifty-three patients after kidney transplantation were included in the study. RESULTS: A total of 47 Caucasian patients (30%) developed UTI, namely - acute pyelonephritis after KTx. We identified independent risk factors associated with UTI such as female gender OR (7.98, 95% CI 2.88-22.12, p < 0.001), diabetes mellitus (OR 5.26, 95% CI 2.01-13.74, p = 0.001; 95% CI 4.57-53.82, p < 0.001) urologic complication (OR 15.68, 95% CI 4.57-53.82; p < 0.001) and acute rejection episode (OR 3.15, 95% CI 1.13-8.76, p = 0.027). The most common microbiological agent was Escherichia coli. CONCLUSION: We identified the aforementioned risk factors of urinary tract infections in the files of our patients. Statistically, the most significant risk factors are the female gender, and presence of urological complications. The urological complications and BMI of the patients are considered modifiable factors. Based on our analysis, we confirmed a significantly higher number of ACR patients who overcame infection which is in accordance with the published data on association of UTI with the development of acute cellular rejection (ACR) (Tab. 2, Fig. 1, Ref. 15).

Comparison of prognosis of five scoring systems in emphysematous pyelonephritis patients requiring intensive care.

INTRODUCTION: Our study aimed to evaluate the performance of Quick Sepsis-related Organ Failure Assessment (qSOFA), Modified Early Warning Score (MEWS), National Early Warning Score (NEWS), Systemic Inflammatory Response Syndrome (SIRS), and Global Research in the Emphysematous Pyelonephritis group (GREMP) in predicting the need of admission in intensive care units (ICU) for emphysematous pyelonephritis (EPN) patient. PATIENTS AND METHODS: In this retrospective study, we reviewed 70 patients admitted to our department from January 2008 to October 2022. Data on clinical presentation and EPN management were noted. The five scoring systems were calculated by one investigator. Univariate and multivariate analyses were used to assess predictive factors of severe sepsis and mortality. Statistical analysis was made using SPSS version 22. RESULTS: Mean age was 61.83 years with 65.7% diabetes. As per Huang and Tseng classification, 41 patients had class I EPN, 7 had class II EPN, 8 had class IIIa, 6 class IIIB EPN, and 8 had class IV EPN. Seventeen patients (24.28%) were admitted to ICU with an 18.57 mortality rate. Univariate analysis showed that ICU admission was significantly associated with higher respiration rate and heart rate, lower systolic blood pressure, confusion, CRP, lactate and creatinine serum (p = 0.0001, p = 0.0001, p = 0.001, p = 0.007, p = 0.004, p = 0.001, p = 0.001, respectively). All five scores and Huang and Tseng classification were significantly predictive of admission to ICU. All five scores showed good results under the area curves to predict ICU entry with 0.915, 0.895, 0.968, 0.887, and 0.846 for qSOFA, MEWS score, NEWS score, SIRS, and GREMP score, respectively. CONCLUSION: NEWS score seemed to be the best performing physiologic score among the five scoring systems studied and may help with biological and radiological findings to quickly identify EPN patients that need intensive care unit.

Emphysematous pyelonephritis with ST elevation accompanied by reciprocal changes mimicking acute coronary syndrome.

Patients with infectious diseases including sepsis can develop ST segment changes on an electrocardiogram (ECG) in the absence of coronary artery disease. However, ST elevation with "reciprocal ST segment depression (RSTD)", which is recognized as a specific finding for ST-elevated myocardial infarction, is rare in such patients. Although a small number of cases have reported ST-segment elevation in gastritis, cholecystitis, and sepsis, regardless of coronary artery disease, none presented with reciprocal changes. Here, we describe a rare case of a patient with emphysematous pyelonephritis complicating septic shock who developed ST elevation accompanied by reciprocal changes with no coronary occlusion. Emergency physicians should consider the possibility of acute coronary syndrome mimicking, and choose non-invasive diagnostic procedures when investigating the causes of ECG abnormalities associated with critically ill patients.

Severe disseminated infection by hypermucoviscous Klebsiella pneumoniae successfully treated by intensive therapy with continuous hemodiafiltration using AN69ST: A case report and review of the literature.

Klebsiella pneumoniae (Kpn) is one of the most common gram-negative bacilli causing lung, urinary tract, and biliary tract infections. However, as a distinct entity from classic Kpn, hypervirulent Kpn causing liver abscess, endophthalmitis, and lung abscess with poor prognoses has been reported mainly in East and Southeast Asia since the mid-1980s. Although the definition of hypervirulent Kpn is unclear, the hypermucoviscosity of Kpn is considered an important feature of hypervirulence. We present a case of emphysematous pyelonephritis accompanied by septic shock and acute kidney injury caused by hypermucoviscous Kpn infection that was successfully treated by intensive treatment. A 70-year-old woman with type 2 diabetes mellitus was diagnosed with emphysematous pyelonephritis, and string test-positive Kpn was detected in blood and urine cultures and percutaneous catheter drainage fluid from the renal pelvis. The patient was treated with intensive therapies including antibiotics, ventilator management, and continuous hemodiafiltration (CHDF) using AN69ST, which can absorb cytokines. During the course of treatment, the infection was complicated by pyogenic spondylitis, which was cured by antimicrobial therapy, and the patient was transferred to another hospital for rehabilitation on day 119 after admission. Hypermucoviscous Kpn infection often has a severe course, and it is important to initiate multidisciplinary treatment at an early stage, including rifampicin, which is expected to inhibit the viscosity of hypermucoviscous Kpn. In the current case, immediate CHDF using AN69ST was also considered a life-saving treatment because it improved both volume overload and neutrophil-activated hypercytokinemia.

[Balloon dilation treatment of primary obstructive megaureter in children].

PURPOSE: Investigation of the results of ureteral stricture single balloon dilation in children with primary obstructive megaureter. MATERIALS AND METHODS: Since 2012 to 2020 79 children (65 boys and 15 girls) with primary obstructive megaureter of II and III grades who had 92 affected ureters were operated on by method of ureteral stricture balloon dilation. Duration of postoperative stenting period was Me=68 [48; 91] days, bladder catheterization period - Me=15 [5; 61] days. Follow-up was from 1 to 10 years. RESULTS: There were no intraoperative complications in the group of investigation. Pyelonephritis exacerbation in the early postoperative period occurred in 15 cases (18,98%). Control comprehensive examination revealed that urodynamics of 63 children (79,74%) tended to normalization what persisted in the future. There was no positive dynamics in 16 cases (20,25%). Vesico-ureteral reflux was revealed in 4 cases. DISCUSSION: Assessment of impact of various predictors (passport, urodynamic, infectious, anatomic, operation and postoperative period characteristics) on the treatment results proved that the effectiveness of the procedure depends on the following factors: ureteral stricture length (M-U Test U=202,5 p=0,0002) and features of the stricture rapture during ballooning (Fisher exact p=0,0006). There was significant difference in results in the group of up to 10 mm inclusive stricture length and the longer stricture group (Fisher exact p=0,00001). High activity of pyelonephritis in postoperative period was the predictor of adverse outcome (Fisher exact p=0,00001). CONCLUSION: Practically 80% of children with primary obstructive megaureter may be reliably cured by the method of ureteral stricture balloon dilation. The risk of intervention failure is greatly increased in case of the stricture length is more than 10 mm and technical difficulties of ballooning indicating a high resistance of the narrowed portion of the ureter to dilation.

[Complex therapy and prevention of exacerbations of calculous pyelo- nephritis].

Urolithiasis in Russia still occupies one of the leading places in the total number of urological nosologies. Acute and chronic calculous pyelonephritis is the most severe complication of urolithiasis, causing destructive kidney damage in the form of apostematous pyelonephritis, abscess, kidney carbuncle and pionephrosis. In the case of acute obstruction of the urinary tract by concretion, purulent kidney damage occurs in a very short period of time and the result of treatment in this case depends on the adequacy and speed of the choice of the method of drainage of the urinary tract, that is, the elimination of their obstruction, as well as the correct choice of rational antibacterial therapy. The article presents three clinical observations of effective treatment of patients with chronic calculous pyelonephritis with Phytolysin paste and Phytosilin capsules as part of complex therapy.

Management of uncomplicated urinary tract infection in the post-antibiotic era: select non-antibiotic approaches.

BACKGROUND: Given the high frequency of patients presenting with urinary tract infections (UTIs) and the ensuing high degree of antibiotic prescription, UTI is a critical point of intervention for non-antibiotic treatments to curb the further development of antimicrobial resistance and provide risk-appropriate care for patients. OBJECTIVES: To highlight several select non-antibiotic therapies for the treatment of uncomplicated UTI and relevant indications (prevention and complicated UTI) from recent literature. SOURCES: PubMed, Google Scholar, and clinicaltrials.gov were searched for clinical trials published in the English language corresponding to non-antibiotic treatments for UTI. CONTENT: The focus of this narrative review centres on a limited number of non-antibiotic therapies for the treatment of UTI based on (a) herbal extracts or (b) antibacterial strategies (e.g. bacteriophage therapy and D-mannose). The experience of treatment with non-steroidal anti-inflammatory drugs is also used to fuel discussion on the risk of developing pyelonephritis without antibiotics-compared with the projected harms of continuing their widespread use. IMPLICATIONS: Non-antibiotic treatment strategies for UTI have shown varying results in clinical trials, and the current evidence does not yet indicate a clear, better alternative to antibiotics. However, the collective experience with non-antibiotic treatments suggests that there is a need to weigh the actual benefits/risks of unfettered, non-culture-confirmed antibiotic use in uncomplicated UTI. Given the different mechanisms of action of proposed alternatives, more in-depth knowledge on microbiological and pathophysiological factors influencing UTI susceptibility and prognostic indicators are highly needed to stratify patients most likely to benefit. The feasibility of alternatives in clinical practice should also be considered.

Antenatal pyelonephritis: a three-year retrospective cohort study of two Irish maternity centres.

Pyelonephritis affects 1-2% of pregnant women, and is associated with significant maternal and fetal morbidity. Antenatal pyelonephritis has been associated with PPROM (preterm premature rupture of membranes), preterm labour, low birth weight (LBW) and prematurity. A three-year retrospective dual-centre cohort study of antenatal pyelonephritis cases was conducted in two neighbouring Irish maternity hospitals - the Rotunda Hospital (RH) and the National Maternity Hospital (NMH). Patient demographics, clinical presentation, investigations, management and maternal/neonatal outcomes were recorded. A total of 47,676 deliveries (24,768 RH; 22,908 NMH) were assessed. 158 cases of antenatal pyelonephritis were identified (n = 88 RH, n = 70 NMH), with an incidence of 0.33%. The median age was 28 years. The median gestation was 27 + 6 weeks, with 51% presenting before 28 weeks' gestation. Risk factors included; obesity (18.4%), diabetes mellitus (13.3%) and self-reported clinical history of recurrent urinary tract infection (28.5%). Rate of relapse with UTI in the same pregnancy was 8.2%. Renal ultrasound was performed in 30.4%. Predominant uropathogens were Escherichia coli (60%), Klebsiella pneumoniae (11%) and Proteus mirabilis (5%). 7.5% of cases had a concurrent bloodstream infection, 13.3% of cases were complicated by sepsis and 1.9% with septic shock. Complications including PPROM (6.3%), preterm delivery < 37 weeks' gestation (11%), LBW < 2,500 g (8.2%) were comparable between sites. Delivery within 72 hours of diagnosis was noted in 7% (n = 11) of patients, of which three were preterm and one had LBW. Appropriate and prompt investigation and management of antenatal pyelonephritis is essential given the associated maternal and neonatal morbidity.

Pyonephrosis among Patients with Pyelonephritis Admitted in Department of Nephrology and Urology of a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Introduction: Pyonephrosis is a severe complication of pyelonephritis leading to rapid progression to sepsis and loss of renal function resulting in nephrectomy. Early identification of pyonephrosis based on clinical or radiological characteristics amongst pyelonephritis is paramount. This study aimed to determine the prevalence of pyonephrosis among patients with pyelonephritis admitted to the Department of Nephrology and Urology of a tertiary care centre. Methods: This descriptive cross-sectional study was done in a tertiary care centre among patients with pyelonephritis from 1 July 2016 to 31 Jan 2021. Ethical approval was obtained from Institution Ethics Committee (Reference number: IEC/56/21). The available clinical, demographic and laboratory parameters were recorded from the hospital records in a predesigned proforma. A convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated. Results: Among 550 pyelonephritis patients, the prevalence of pyonephrosis was 60 (10.9%) (8.3-13.5, 95% Confidence Interval). The mean age was 54.62±12.14 years, and 41 (68.33%) were males. The most common clinical symptom was flank pain with or without fever in 46 (76.66%) patients. Escherichia coli was the most common offending organism in 20 (33.33%). Ultrasonography showed classical echogenic debris with floaters and internal echoes in 44 (73.33%) patients. Double J stenting was successfully done in 44 (73.33%) patients. Percutaneous nephrostomy was done in the remaining 16 (26.66%) patients. Conclusions: The prevalence of pyonephrosis in pyelonephritis is similar to previous studies done in similar settings. Keywords: pyelonephritis; pyonephrosis; kidneys.

Impact of early ureteral drainage on mortality in obstructive pyelonephritis with urolithiasis: an analysis of the Japanese National Database.

BACKGROUND: The impact of early drainage on mortality in patients with obstructive pyelonephritis with urolithiasis was evaluated. METHODS: We identified 34,924 patients in the Japanese Diagnosis Procedure Combination database with obstructive pyelonephritis with urolithiasis receiving ureteral drainage. The effects of early drainage (1-2 days) compared to those of delayed drainage (on 3-4 and ≥ 5 hospital days) on mortality were evaluated among 31,696 patients hospitalized for ≥ 5 days. Multivariate analysis was performed to identify independent factors for mortality. RESULTS: The mortality rates for overall cases and those hospitalized for ≥ 5 days were 2.0% and 1.6%, respectively. Those receiving drainage on 1-2, 3-4, and ≥ 5 days had mortality rates of 1.5%, 2.0%, and 2.5%, respectively (p < 0.001). Multivariate analysis revealed that delayed drainage was an independent factor for higher mortality (odds ratio [OR] on days 3-4 and ≥ 5; 1.44, p = 0.018; and 1.69, p < 0.001). Increasing age (OR for 60 s, 70 s, and ≥ 80 years; 2.02, 3.85, and 7.77), Charlson comorbidity index score (OR, 1.41 by 1-point increase), disseminated intravascular coagulation (OR, 2.40), ambulance use (OR, 1.22), impaired consciousness at admission (disoriented, arousable with stimulation, and unarousable; OR 1.58, 2.84, and 5.50), and nephrostomy (OR, 1.65) were associated with higher mortality. In contrast, female sex (OR, 0.76) and high hospital volume (OR on 9-16, and ≥ 17 cases/year; 0.80, and 0.75) were associated with lower mortality. CONCLUSION: Ureteral drainage within 2 hospital days was an independent factor for low mortality in obstructive pyelonephritis with urolithiasis. Delayed drainage could increase mortality in a time-dependent manner.

A biomarker for bacteremia in pregnant women with acute pyelonephritis: soluble suppressor of tumorigenicity 2 or sST2.

Objective: Sepsis is a leading cause of maternal death, and its diagnosis during the golden hour is critical to improve survival. Acute pyelonephritis in pregnancy is a risk factor for obstetrical and medical complications, and it is a major cause of sepsis, as bacteremia complicates 15-20% of pyelonephritis episodes in pregnancy. The diagnosis of bacteremia currently relies on blood cultures, whereas a rapid test could allow timely management and improved outcomes. Soluble suppression of tumorigenicity 2 (sST2) was previously proposed as a biomarker for sepsis in non-pregnant adults and children. This study was designed to determine whether maternal plasma concentrations of sST2 in pregnant patients with pyelonephritis can help to identify those at risk for bacteremia.Study design: This cross-sectional study included women with normal pregnancy (n = 131) and pregnant women with acute pyelonephritis (n = 36). Acute pyelonephritis was diagnosed based on a combination of clinical findings and a positive urine culture. Patients were further classified according to the results of blood cultures into those with and without bacteremia. Plasma concentrations of sST2 were determined by a sensitive immunoassay. Non-parametric statistics were used for analysis.Results: The maternal plasma sST2 concentration increased with gestational age in normal pregnancies. Pregnant patients with acute pyelonephritis had a higher median (interquartile range) plasma sST2 concentration than those with a normal pregnancy [85 (47-239) ng/mL vs. 31 (14-52) ng/mL, p < .001]. Among patients with pyelonephritis, those with a positive blood culture had a median plasma concentration of sST2 higher than that of patients with a negative blood culture [258 (IQR: 75-305) ng/mL vs. 83 (IQR: 46-153) ng/mL; p = .03]. An elevated plasma concentration of sST2 ≥ 215 ng/mL had a sensitivity of 73% and a specificity of 95% (area under the receiver operating characteristic curve, 0.74; p = .003) with a positive likelihood ratio of 13.8 and a negative likelihood ratio of 0.3 for the identification of patients who had a positive blood culture.Conclusion: sST2 is a candidate biomarker to identify bacteremia in pregnant women with pyelonephritis. Rapid identification of these patients may optimize patient care.