Urine D-arabinitol/L-arabinitol ratio in diagnosing Candida infection in patients with haematological malignancy and HIV infection

Prospective evaluation of a combination of fungal biomarkers for the diagnosis of invasive fungal disease in high-risk haematology patients

We prospectively evaluated a combination of fungal biomarkers in adult haematology patients with focus on their clinical utility at different time points during the course of infection. In total, 135 patients were monitored once to twice weekly for serum (1-3)-ß-d-glucan (BG), galactomannan (GM), bis-methyl-gliotoxin and urinary d-arabinitol/l-arabinitol ratio. In all, 13 cases with proven or probable invasive fungal disease (IFD) were identified. The sensitivity of BG and GM at the time of diagnosis (TOD) was low, but within 2 weeks from the TOD the sensitivity of BG was 92%. BG >800 pg/mL was highly specific for IFD. At a pre-test probability of 12%, both BG and GM had negative predictive values (NPV) >0.9 but low positive predictive values (PPV). In a subgroup analysis of patients with clinically suspected IFD (pre-test probability of 35%), the NPV was lower, but the PPV for BG was 0.86 at cut-off 160 pg/mL. Among IFD patients, 91% had patterns of consecutively positive and increasing BG levels. Bis-methyl-gliotoxin was undetectable in 15 patients with proven, probable and possible IA. To conclude, BG was the superior fungal marker for IFD diagnosis. Quantification above the limit of detection and graphical evaluation of the pattern of dynamics are warranted in the interpretation of BG results.

Detection ofCandida albicans by culture, serology and PCR in clinical specimens from patients with ulcerative colitis: Re-evaluation of an old hypothesis with a new perspective

The relationship between inflammatory bowel disease and microorganisms was evaluated. The presence of Candida albicans-specific IgM and IgG antibodies in serum samples and the presence of C. albicans in stool and colonal mucosa samples of the patients did not exhibit any significant difference between 21 patients in active stage and 15 patients in remission of ulcerative colitis (UC) (compared with 19 control patients). The invasion of yeast cells to the colonal mucosa was demonstrated by detecting C. albicans DNA using specific PCon1, PCon2, and PspA2 primers in PCR assay. Eighteen of 36 patients (50%) were found to be DNA positive while in 19 controls only 4 (21%) were found to be positive. The presence of DNA in the association of the positive serological reactivity is suggested as an important diagnostic marker of UC.

Development and application of a rapid diagnostic method for invasive Candidiasis by the detection of d-/l-arabinitol using gas chromatography/mass spectrometry

A rapid non-culture-based diagnostic method utilizing d-/l-arabinitol (DA/LA) ratios as a chemical marker of invasive candidiasis was developed and explored. The enantiomers-ratios detection was made possible by the use of gas chromatography coupled with mass spectrometry (GC/MS). The mean DA/LA ratios +/- standard deviation (range) in urine (n = 40) and serum (n = 20) were 2.08 +/- 0.78 (0.57 to 3.55) and 1.79 +/- 0.75 (0.74 to 3.54), respectively, from patients without evidence of fungal infection or colonization; in patients (n = 7) with culture-proven invasive candida infections, the figures were 9.91 +/- 3.04 (7.24 to 16.27) and 13.58 +/- 7.31 (5.57 to 25.88) in urine and serum, respectively. The differences in DA/LA ratios between the candidemic patients and the non-candidemic patients were statistically significant (p < 0.01) in both serum and urine samples. The DA/LA ratios were not significantly affected in patients with oral or vaginal candidiasis and candiduria.