# P-1742. The Role of T2 Candida in the Early Detection of Invasive Candidiasis Among Solid Organ Transplant Patients

## TL;DR

This study examines how the T2Candida test helps detect invasive Candidiasis in solid organ transplant patients and its impact on clinical outcomes.

## Contribution

The study provides insights into the clinical utility of T2Candida in diagnosing invasive Candidiasis among transplant recipients.

## Key findings

- T2Candida testing showed varying outcomes based on whether it was positive or negative with or without culture confirmation.
- Patients with positive T2Candida results had different mortality and readmission rates compared to those with negative results.
- The test detected multiple Candida species in transplant recipients with suspected infections.

## Abstract

Invasive Candidiasis (IC) is the leading cause of invasive fungal infections in solid organ transplant recipients (SOTr). T2Candida is a rapid diagnostic test that can improve antifungal use in SOTr. We describe the clinical characteristics and outcomes of SOTr who underwent T2Candida testing (T2) for suspected IC at our institution.Table 1.Demographics, risk factors, and clinical presentation of suspected/confirmed IC in SOTr with T2pos-IC vs T2pos-alone and T2neg-IC vs T2neg-alone (n= 305)a Sepsis was classified as 2/4 Systemic Inflammatory Response Syndrome criteria.b Septic Shock was classified as sepsis with hypotension requiring pressor use.c Fungemia alone was classified as patients with positive blood cultures, but no positive sterile tissue cultures for Candida spp. within 48hrs of T2 collection.d Deep-seated infection alone was classified as negative blood cultures, but positive sterile tissue cultures for Candida spp. within 48hrs of T2 collection.e p values calculated by Wilcoxon rank sum tests (continuous variables) and Fischer's Exact test (categorical variables)Abbreviations: CCI, Charlson Comorbidity Index; IQR, Interquartile Range; IC, invasive candidiasis; T2pos-alone, patients with isolated positive T2Candida® Panel without corresponding isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection; T2pos-IC, patients with positive T2Candida® Panel with isolation of Candida spp. on blood/sterile tissue cultures within 48hrs of T2 collection; T2neg-alone, patients with negative T2Candida® Panel and negative blood/sterile cultures within 48hrs of T2 collection; T2neg-IC, patients with negative T2Candida® Panel and isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection.Figure 1.Types of transplanted organs in SOTr who underwent T2Candida® Panel testing (n = 305)a T2Candida Positive, noted in dark blue, refers to any patient with a positive T2Candida® Panel.b T2 Candida Negative, noted in light blue, refers to any patient with a negativeT2Candida® Panel.c Other refers to patients with other combinations of organ transplants (e.g. kidney/pancreas was most frequent).d Multivisceral includes patients with ≥ 3 abdominal organs transplanted.Abbreviations: SOTr, Solid organ transplant recipients

Demographics, risk factors, and clinical presentation of suspected/confirmed IC in SOTr with T2pos-IC vs T2pos-alone and T2neg-IC vs T2neg-alone (n= 305)

a Sepsis was classified as 2/4 Systemic Inflammatory Response Syndrome criteria.

b Septic Shock was classified as sepsis with hypotension requiring pressor use.

c Fungemia alone was classified as patients with positive blood cultures, but no positive sterile tissue cultures for Candida spp. within 48hrs of T2 collection.

d Deep-seated infection alone was classified as negative blood cultures, but positive sterile tissue cultures for Candida spp. within 48hrs of T2 collection.

e p values calculated by Wilcoxon rank sum tests (continuous variables) and Fischer's Exact test (categorical variables)

Abbreviations: CCI, Charlson Comorbidity Index; IQR, Interquartile Range; IC, invasive candidiasis; T2pos-alone, patients with isolated positive T2Candida® Panel without corresponding isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection; T2pos-IC, patients with positive T2Candida® Panel with isolation of Candida spp. on blood/sterile tissue cultures within 48hrs of T2 collection; T2neg-alone, patients with negative T2Candida® Panel and negative blood/sterile cultures within 48hrs of T2 collection; T2neg-IC, patients with negative T2Candida® Panel and isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection.

Types of transplanted organs in SOTr who underwent T2Candida® Panel testing (n = 305)

a T2Candida Positive, noted in dark blue, refers to any patient with a positive T2Candida® Panel.

b T2 Candida Negative, noted in light blue, refers to any patient with a negativeT2Candida® Panel.

c Other refers to patients with other combinations of organ transplants (e.g. kidney/pancreas was most frequent).

d Multivisceral includes patients with ≥ 3 abdominal organs transplanted.

Abbreviations: SOTr, Solid organ transplant recipients

A retrospective study including adult SOTr who underwent T2 for suspected IC between 01/2015-12/2024. We compared data of patients with positive T2 alone (T2pos-alone) vs. positive T2/positive culture from sterile site (T2pos-IC), and patients with negative T2 (T2neg-alone) vs. negative T2/positive culture (T2neg-IC).Figure 2.Candida species detected by T2Candida® Panel in SOTr with T2pos-alone and T2pos-IC (n=43)a Total population, all patients with a positive T2Candida® Panel, denoted in dark grey.b T2pos-alone, patients with isolated positive T2Candida® Panel without corresponding isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection, denoted in light grey.c T2pos-IC, patients with positive T2Candida® Panel with isolation of Candida spp. on blood/sterile tissue cultures within 48hrs of T2 collection, denoted in dark blue.d p values calculated via Fischer's Exact test.Abbreviations: SOTr, Solid organ transplant recipients; C, Candida; IC, invasive candidiasisTable 2.Clinical Outcomes of SOTr with T2pos-IC vs T2pos-alone and T2neg-IC vs T2neg-alone (n = 305)a All-cause mortality refers to death from any cause.b Mortality related to IC refers to death because of documented sepsis secondary to Candida spp. identified on sterile cultures.c Readmission for relapsed infection refers to patients hospitalized for worsened documented infectious signs or symptoms via clinical evaluation or imaging studies demonstrating worsened deep-seated infection.d p values calculated via Wilcoxon rank sum tests (continuous variables) and Fischer's Exact test (categorical variables)Abbreviations: IQR, Interquartile Range; IC, invasive candidiasis; T2pos-alone, patients with isolated positive T2Candida® Panel without corresponding isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection; T2pos-IC, patients with positive T2Candida® Panel with isolation of Candida spp. on blood/sterile tissue cultures within 48hrs of T2 collection; T2neg-alone, patients with negative T2Candida® Panel and negative blood/sterile cultures within 48hrs of T2 collection; T2neg-IC, patients with negative T2Candida® Panel and isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection.

Candida species detected by T2Candida® Panel in SOTr with T2pos-alone and T2pos-IC (n=43)

a Total population, all patients with a positive T2Candida® Panel, denoted in dark grey.

b T2pos-alone, patients with isolated positive T2Candida® Panel without corresponding isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection, denoted in light grey.

c T2pos-IC, patients with positive T2Candida® Panel with isolation of Candida spp. on blood/sterile tissue cultures within 48hrs of T2 collection, denoted in dark blue.

d p values calculated via Fischer's Exact test.

Abbreviations: SOTr, Solid organ transplant recipients; C, Candida; IC, invasive candidiasis

Clinical Outcomes of SOTr with T2pos-IC vs T2pos-alone and T2neg-IC vs T2neg-alone (n = 305)

a All-cause mortality refers to death from any cause.

b Mortality related to IC refers to death because of documented sepsis secondary to Candida spp. identified on sterile cultures.

c Readmission for relapsed infection refers to patients hospitalized for worsened documented infectious signs or symptoms via clinical evaluation or imaging studies demonstrating worsened deep-seated infection.

d p values calculated via Wilcoxon rank sum tests (continuous variables) and Fischer's Exact test (categorical variables)

Abbreviations: IQR, Interquartile Range; IC, invasive candidiasis; T2pos-alone, patients with isolated positive T2Candida® Panel without corresponding isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection; T2pos-IC, patients with positive T2Candida® Panel with isolation of Candida spp. on blood/sterile tissue cultures within 48hrs of T2 collection; T2neg-alone, patients with negative T2Candida® Panel and negative blood/sterile cultures within 48hrs of T2 collection; T2neg-IC, patients with negative T2Candida® Panel and isolation of Candida spp. on blood/sterile cultures within 48hrs of T2 collection.

From the 305 SOTr included, 43 (14%) had a positive T2. Baseline characteristics were comparable between groups (Table 1). Median time from transplant to suspected/confirmed IC was 284 [33-2659] days. Transplanted organs included liver (36%), kidney (22%), and lung (17%) (Fig 1). In SOTr with positive T2, 13 (30%) had concomitant isolation of Candida spp. in cultures (T2pos-IC) (Fig 2). Median duration of hospitalization and antifungal therapy (AFT) was significantly shorter in the T2pos-alone group vs. T2pos-IC (19 vs. 49 days, p=0.03, 14 vs. 19 days, p=0.04, respectively). 90-day all-cause mortality was highest in T2pos-IC (Table 2). In SOTr with negative T2, 248 (95%) did not have concomitant isolation of Candida spp. in cultures (T2neg-alone). Based on T2 results, 64 (24%) SOTr stopped AFT in ≤48hrs and 145 (55%) did not receive any AFT. Median duration of AFT, IC-related 90-day mortality, and readmission due to relapsed infection were significantly lower in the T2neg-alone group compared to T2Neg-IC (2 vs. 25 days, p< 0.01, 1% vs 14% p=0.02, 0 vs 14% p< 0.01, respectively) (Table 2).

SOTr with T2pos-IC had higher mortality and significantly higher duration of hospitalization and AFT compared to T2pos-alone. A negative T2 frequently prompted discontinuation or avoidance of AFT. Patients with T2neg-alone had low mortality and no readmission for suspected IC. Further studies are needed to evaluate the role of rapid diagnostics in the SOTr population.

All Authors: No reported disclosures