CLINICAL NEWS
“Thrombocytopenic sepsis
patients have a different and
more disturbed host response.”
—THEODORA A.M. CLAUSHUIS, MD
Using the lowest platelet count
within the first 24 hours of ICU
admission, patients were also stratified into groups according to:
• Very-low platelet counts: <50 x
109/L (n=61; 6.6%)
• Intermediate-low platelet counts:
50-99 x 109/L (n=121; 13%)
• Low platelet counts: 100-149 x
109/L (n=167; 17.9%)
• Normal platelet counts: 150-399
x 109/L (n=580; 62.3%)
To account for baseline differences
other than platelet counts (demographics, chronic comorbidity,
concomitant drugs, medical admission type, and primary source
of infection) the authors used
propensity score matching. Results
were also compared to normal
values generated from plasma
from 27 age- and gender-matched
healthy volunteers.
“Platelet counts remained
relatively stable across all groups in
the first four to six days after ICU
admission,” Dr. Claushuis and coauthors noted. “Thereafter, platelet
counts [tended to] increase,
although patients with very-low
platelet counts remained thrombocytopenic for prolonged periods of
time while in the ICU.”
Patients with very-low platelet
counts were more likely to be
younger than those with low or
normal platelet counts, had fewer
comorbidities, and were more often admitted for medical reasons.
Among all platelet count groups,
the primary source of infection
was similar, though patients with
normal platelet counts were more
often admitted with pulmonary
sepsis and less often with urinary sepsis. Patients with low or
intermediate-low platelet counts
were more severely ill at admission (as indicated by higher Acute
Physiology and Chronic Health
Evaluation IV and Sequential Organ Failure Assessment scores).
Patients in the very-low and
intermediate-low platelet groups
had a higher risk of mortality in
the ICU, as well as a higher risk of
mortality at day 30 and up to one
year after ICU admission (TABLE
2), compared with patients with
normal platelet counts (hazard
ratios [HR] = 2.00 [1.32-3.05] and
1.72 [1.22-2.44], respectively; p
values not reported).
Full outcomes of sepsis stratified by platelet counts at admission
to the ICU are presented in TABLE 2.
“[Evaluation of the genomic
response of blood leukocytes
showed that] thrombocytopenia was associated with a more
disturbed host response, independent of disease severity,” Dr.
Claushuis added. “Sepsis patients
with thrombocytopenia had
more impaired vascular integrity,
increased cytokine levels, and had
leukocytes with reduced (RNA)
signaling in adhesion and diapedesis, compared with patients
with normal platelet counts.”
The researchers also observed
a distinct whole-blood leukocyte
transcriptome pattern, revealing
decreased leukocyte adhesion,
diapedesis, and extravasation
signaling.
“The association between
increased mortality and thrombocytopenia is generally regarded
as a reflection of disease severity,”
Dr. Claushuis concluded. “Our
study shows that apart from this,
thrombocytopenic sepsis patients
also have a different and more
disturbed host response.”
The study results are limited in
generalizability due to the location
at two sites in the Netherlands. Additionally, though the researchers
used propensity-matching to correct for baseline differences, they
noted, “a bias may have remained
after propensity matching due to
unmeasured confounders.”
REFERENCE
Claushuis TAM, van Vught LA, Scicluna BP, et al.
Thrombocytopenia is associated with a dysregulated host
response in critically ill sepsis patients. Blood. 2016 March
8. [Epub ahead of print]
Outcomes of Sepsis Patients Stratified by Platelet Counts at ICU
Admission
TABLE 2.
Patients
Very low
(<50x109/L)
Intermediate-low
(50-99x109/L)
Low
(100-149x109/L)
Normal
(150-399x109/L)
61 (6.6%)
121 (13%)
167 (17.9%)
580 (62.3%)
p value
Median length of stay, in days