T-antigen activation for prediction of pneumococcus-induced hemolytic uremic syndrome and hemolytic anemia.
BACKGROUND
Among the most severe complications of invasive pneumococcal infection are hemolytic uremic syndrome (P-HUS) and hemolytic anemia (P-HA), which occur when the Thomsen-Freidenreich antigen (TA) is exposed on erythrocytes, platelets and glomeruli.


METHODS
To determine the positive predictive value, sensitivity, and specificity of early TA activation testing for P-HUS or P-HA and to compare the microbiologic features of pneumococcus isolates associated or not associated with TA activation. The case records for 36 patients with invasive pneumococcal infection who had been tested for TA activation were retrospectively reviewed. Clinical and laboratory data were compared between patients with and without TA activation.


RESULTS
Positive TA activation was 86% sensitive and 57% specific for P-HUS or P-HA. The positive predictive value was 76%. There were no between-group differences in antibiotic susceptibility of the pneumococcal isolates. Pneumococcal serotype 14 was the most frequent (5/10 isolates tested) serotype causing P-HUS. Of the 36 patients, 13 required packed red blood cell transfusion, 3 died, and 2 required extracorporeal membrane oxygenation. No patient had long-term renal sequelae.


CONCLUSIONS
TA activation is a reasonable predictor of P-HUS or P-HA and could be useful if tested soon after invasive pneumococcal disease is first diagnosed.
Huang
Daniel Tsung-Ning
DT
Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan.
Chi
Hsin
H
Lee
Hung-Chang
HC
Chiu
Nan-Chang
NC
Huang
Fu-Yuan
FY
D000743:Anemia, Hemolytic / Q000097:blood / Q000276:immunology / Q000382:microbiology*; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood / Q000276:immunology*; D002439:Cefotaxime / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006463:Hemolytic-Uremic Syndrome / Q000097:blood / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D010406:Penicillins / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000097:blood / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification*; D013624:Taiwan
D015295:Antigens, Tumor-Associated, Carbohydrate; D010406:Penicillins; C016467:Thomsen-Friedenreich antigen; D002439:Cefotaxime