Rationale: The global burden of sepsis is concentrated in sub-Saharan
Africa, where inciting pathogens are diverse and HIV co-infection is a
major driver of poor outcomes. Biological heterogeneity inherent to sepsis
in this setting is poorly defined. Objectives: To identify dominant
pathobiological signatures of sepsis in sub-Saharan Africa and their
relationship to clinical phenotypes, patient outcomes, and biological
classifications of sepsis identified in high-income countries (HICs).
Methods: We analyzed two prospective cohorts of adults hospitalized with
sepsis (severe infection with qSOFA score≥1) at disparate settings in
Uganda (discovery cohort [Entebbe, urban], N=242; validation cohort
[Tororo, rural], N=253). To identify pathobiological signatures in the
discovery cohort, we applied unsupervised clustering to 173 soluble
proteins reflecting key domains of the host response to severe infection.
A random forest-derived classifier was used to predict signature
assignment in the validation cohort. Measurements and Main Results: Two
signatures (Uganda Sepsis Signature [USS]-1 and USS-2) were identified in
the discovery cohort, distinguished by expression of proteins involved in
myeloid cell and inflammasome activation, T cell co-stimulation and
exhaustion, and endothelial barrier dysfunction. A five-protein classifier
(AUROC 0.97) reproduced two signatures in the validation cohort with
similar biological profiles. In both cohorts, USS-2 mapped to a more
severe clinical phenotype associated with HIV and related
immunosuppression, severe tuberculosis, and increased risk of 30-day
mortality. Substantial biological overlap was observed between USS-2 and
hyperinflammatory and reactive sepsis phenotypes identified in
HICs. Conclusions: We identified
prognostically-enriched pathobiological signatures among sepsis patients
with diverse infections and high HIV prevalence in Uganda. Globally
inclusive investigations are needed to define generalizable and
context-specific mechanisms of sepsis pathobiology, with the goal of
improving access to precision medicine treatment strategies. In cryopreserved serum samples, Olink proteomics (Olink
Proteomics AB, Uppsala, Sweden) was performed at the Human Immune
Monitoring Center of the Icahn School of Medicine at Mount Sinai (New
York, NY, USA) using Target Immunooncology and Cardiometabolic panels.
These panels, each of which include 92 proteins, were selected to broadly
capture pathobiological domains implicated in the host response to severe
infection (i.e., innate and adaptive immune activation and exhaustion,
endothelial and cellular metabolic dysfunction, dysregulated coagulation).
Comprehensive descriptions of each panel including validation data are
available at
olink.com and
olink.com. Samples
from RESERVE-U-1-EBB and RESERVE-U-2-TOR were analyzed separately. For
each cohort, samples were analyzed in a single batch, randomized across
plates, and analyzed by technicians blinded to clinical data. For each
panel, proteins were quantified via the Olink Proximity Extension Assay.
The Proximity Extension Assay uses dual oligonucleotide-labelled
antibodies to bind target proteins, creating a unique double stranded DNA
barcode which is quantitatively proportional to the initial concentration
of the target protein. This barcode then serves as a template for a DNA
polymerase-dependent extension step, which is followed by PCR
amplification (T100 Thermal Cycle, Bio-Rad Laboratories, Inc., Hercules,
CA, USA). Resulting DNA amplicons are quantified by microfluidic qPCR
(Fluidigm Biomark HD and JUNO Systems, Standard BioTools Inc., San
Francisco, CA, USA) and normalized across batch plates. Intensity
normalization was used for RESERVE-U-1-EBB assays and reference sample
normalization was used for RESERVE-U-2-TOR assays. Relative protein
abundance was calculated from cycle threshold values and expressed in
log
2-normalized protein expression (NPX) units by
Olink’s NPX Manager software. Missing NPX values, which were rare, were
multiply imputed for each panel using chained equations, predictive mean
matching, and all other proteins as predictors (
mice
R package). Five imputed datasets were reviewed for convergence and
plausibility after which one was randomly selected for use. # Olink proteomic data for RESERVE-U-1-EBB and RESERVE-U-2-TOR Cohorts
**Description of the Data and File structure:** Two files are provided
corresponding to adult patients (age >=18 years) enrolled in the
RESERVE-U-1-EBB (2017-2019) and RESERVE-U-2-TOR (2021-2023) cohorts.
Although analyses presented in the manuscript were restricted to patients
with qSOFA score >=1, data is provided for patients enrolled in the
above cohorts regardless of qSOFA score. In each file, the "pid"
column reflects the persistent unique identifier for each sample. The
remainder of columns reflect relative protein abundance as quantified in
serum using the Olink Target Immunooncology and Cardiometabolic panels
(Olink Proteomics AB, Uppsala, Sweden). Relative protein abundance is
expressed in log2-normalized protein expression (NPX) units as generated
by Olink’s NPX Manager software. Details of all quantified proteins
(protein name, Uniprot code, and proportion of missing values in each
cohort) are presented below. As described in the Methods section, missing
NPX values were imputed for each panel using chained equations, predictive
mean matching, and all other proteins as predictors. **Olink
Immunooncology Panel** | **Protein** | **Uniprot Code** | **Proportion of
missing NPX values in RESERVE-U-1-EBB (%)** | **Proportion of missing NPX
values in RESERVE-U-2-TOR (%)** | | :------------- | :--------------- |
:---------------------------------------------------------- |
:---------------------------------------------------------- | | IL-8 |
P10145 | 0.0 | 0.0 | | TNFRSF9 | Q07011 | 0.0 | 0.0 | | TIE2 | Q02763 |
0.0 | 0.0 | | MCP-3 | P80098 | 0.0 | 0.0 | | CD40-L | P29965 | 0.0 | 0.0 |
| IL-1α# | P01583 | 0.0 | 0.3 | | CD244 | Q9BZW8 | 0.0 | 0.0 | | EGF |
P01133 | 0.0 | 0.0 | | ANGPT1 | Q15389 | 0.0 | 0.0 | | IL-7 | P13232 | 0.0
| 0.0 | | PGF | P49763 | 0.0 | 0.0 | | IL-6 | P05231 | 0.0 | 0.0 | |
ADGRG1 | Q9Y653 | 0.0 | 0.0 | | MCP-1 | P13500 | 0.0 | 0.0 | | CRTAM |
O95727 | 0.0 | 0.0 | | CXCL11 | O14625 | 0.0 | 0.0 | | MCP-4 | Q99616 |
0.0 | 0.0 | | TRAIL | P50591 | 0.0 | 0.0 | | FGF2 | P09038 | 0.0 | 0.0 | |
CXCL9 | Q07325 | 0.0 | 0.0 | | CD8A | P01732 | 0.0 | 0.0 | | CAIX | Q16790
| 0.0 | 0.0 | | MUC-16 | Q8WXI7 | 0.0 | 0.0 | | ADA | P00813 | 0.0 | 0.0 |
| CD4 | P01730 | 0.0 | 0.0 | | NOS3 | P29474 | 0.0 | 0.0 | | IL-2# |
P60568 | 0.0 | 1.4 | | Gal-9 | O00182 | 0.0 | 0.0 | | VEGFR-2 | P35968 |
0.0 | 0.0 | | CD40 | P25942 | 0.0 | 0.0 | | IL-18 | Q14116 | 0.0 | 0.0 | |
GZMH | P20718 | 0.0 | 0.0 | | KIR3DL1 | P43629 | 0.0 | 0.0 | | LAP TGF-β
-1 | P01137 | 0.0 | 0.0 | | CXCL1 | P09341 | 0.0 | 0.0 | | TNFSF14 |
O43557 | 0.0 | 0.0 | | IL-33# | O95760 | 0.0 | 0.0 | | TWEAK | O43508 |
0.0 | 0.0 | | PDGF subunit B | P01127 | 0.0 | 0.0 | | PDCD1 | Q15116 | 0.0
| 0.0 | | FASLG | P48023 | 0.0 | 0.0 | | CD28 | P10747 | 0.0 | 0.0 | |
CCL19 | Q99731 | 0.0 | 0.0 | | MCP-2 | P80075 | 0.0 | 0.0 | | CCL4 |
P13236 | 0.0 | 0.0 | | IL-15 | P40933 | 0.0 | 0.0 | | Gal-1 | P09382 | 0.0
| 0.0 | | PD-L1 | Q9NZQ7 | 0.0 | 0.0 | | CD27 | P26842 | 0.0 | 0.0 | |
CXCL5 | P42830 | 0.0 | 0.0 | | IL-5 | P05113 | 1.8 | 1.1 | | HGF | P14210
| 0.0 | 0.0 | | GZMA | P12544 | 0.0 | 0.0 | | HO-1 | P09601 | 0.0 | 0.0 |
| CX3CL1 | P78423 | 0.0 | 0.0 | | CXCL10 | P02778 | 0.0 | 0.0 | | CD70 |
P32970 | 0.0 | 0.0 | | IL-10 | P22301 | 0.0 | 0.0 | | TNFRSF12A | Q9NP84 |
0.0 | 0.0 | | CCL23 | P55773 | 0.0 | 0.0 | | CD5 | P06127 | 0.0 | 0.0 | |
CCL3 | P10147 | 0.0 | 0.0 | | MMP7 | P09237 | 0.0 | 0.0 | | ARG1 | P05089
| 0.0 | 0.0 | | NCR1 | O76036 | 0.0 | 0.0 | | DCN | P07585 | 0.0 | 0.0 | |
TNFRSF21 | O75509 | 0.0 | 0.0 | | TNFRSF4 | P43489 | 0.0 | 0.0 | | MIC-A/B
| Q29983,Q29980 | 0.0 | 0.0 | | CCL17 | Q92583 | 0.0 | 0.0 | | ANGPT2 |
O15123 | 0.0 | 0.0 | | PTN | P21246 | 0.0 | 0.0 | | CXCL12 | P48061 | 0.0
| 0.0 | | IFN-γ | P01579 | 0.0 | 0.0 | | LAMP3 | Q9UQV4 | 0.0 | 0.0 | |
CASP-8 | Q14790 | 0.0 | 0.0 | | ICOSLG | O75144 | 0.0 | 0.0 | | MMP12 |
P39900 | 0.0 | 0.0 | | CXCL13 | O43927 | 0.0 | 0.0 | | PD-L2 | Q9BQ51 |
0.0 | 0.0 | | VEGFA | P15692 | 0.0 | 0.0 | | IL-4# | P05112 | 4.3 | 7.0 |
| LAG3 | P18627 | 0.0 | 0.0 | | IL12RB1 | P42701 | 0.0 | 0.0 | | IL-13# |
P35225 | 0.0 | 0.0 | | CCL20 | P78556 | 0.0 | 0.0 | | TNF | P01375 | 0.0 |
0.0 | | KLRD1 | Q13241 | 0.0 | 0.0 | | GZMB | P10144 | 0.0 | 0.0 | | CD83
| Q01151 | 0.0 | 0.0 | | IL-12 | P29459,P29460 | 0.0 | 0.0 | | CSF-1 |
P09603 | 0.0 | 0.0 | Legend: #<20% of NPX values above panel’s
estimated limit of detection. **Olink Cardiometabolic Panel** |
**Protein** | **Uniprot Code** | **Proportion of missing NPX values in
RESERVE-U-1-EBB (%)** | **Proportion of missing NPX values in
RESERVE-U-2-TOR (%)** | | :---------- | :--------------- |
:---------------------------------------------------------- |
:---------------------------------------------------------- | | PRCP# |
P42785 | 0.0 | 0.0 | | CA1 | P00915 | 0.0 | 0.0 | | ICAM1 | P05362 | 0.0 |
0.0 | | CHL1 | O00533 | 0.0 | 0.0 | | TGFBI | Q15582 | 0.0 | 0.0 | | ENG |
P17813 | 0.0 | 0.0 | | PLTP | P55058 | 0.0 | 0.0 | | SERPINA7 | P05543 |
0.0 | 0.0 | | IGFBP3 | P17936 | 0.0 | 0.0 | | CR2 | P20023 | 0.0 | 0.0 | |
SERPINA5 | P05154 | 0.0 | 0.0 | | FCGR3B | O75015 | 0.0 | 0.0 | | IGFBP6 |
P24592 | 0.0 | 0.0 | | CDH1 | P12830 | 0.0 | 0.0 | | CCL5 | P13501 | 0.0 |
0.0 | | CCL14 | Q16627 | 0.0 | 0.0 | | GNLY | P22749 | 0.0 | 0.0 | |
NOTCH1 | P46531 | 0.0 | 0.0 | | PAM | P19021 | 0.0 | 0.0 | | PROC | P04070
| 0.0 | 0.0 | | CST3 | P01034 | 0.0 | 0.0 | | NCAM1 | P13591 | 0.0 | 0.0 |
| PCOLCE | Q15113 | 0.0 | 0.0 | | LILRB1 | Q8NHL6 | 0.0 | 0.0 | | MET |
P08581 | 0.0 | 0.0 | | LTBP2# | Q14767 | 0.0 | 0.0 | | IL7R | P16871 | 0.0
| 0.0 | | VCAM1 | P19320 | 0.0 | 0.0 | | SELL | P14151 | 0.0 | 0.0 | | F11
| P03951 | 0.0 | 0.0 | | COMP | P49747 | 0.0 | 0.0 | | CA4 | P22748 | 0.0
| 0.0 | | PTPRS | Q13332 | 0.0 | 0.0 | | MBL2 | P11226 | 0.0 | 0.0 | |
TIMP1 | P01033 | 0.0 | 0.0 | | ANGPTL3 | Q9Y5C1 | 0.0 | 0.0 | | REG3A |
Q06141 | 0.0 | 0.0 | | SOD1# | P00441 | 0.0 | 0.0 | | CD46 | P15529 | 0.0
| 0.0 | | ITGAM# | P11215 | 0.0 | 0.0 | | TNC | P24821 | 0.0 | 0.0 | |
NID1 | P14543 | 0.0 | 0.0 | | CFHR5 | Q9BXR6 | 0.0 | 0.0 | | SPARCL1 |
Q14515 | 0.0 | 0.0 | | PLXNB2 | O15031 | 0.0 | 0.0 | | MEGF9 | Q9H1U4 |
0.0 | 0.0 | | ANG | P03950 | 0.0 | 0.0 | | ST6GAL1 | P15907 | 0.0 | 0.0 |
| DPP4 | P27487 | 0.0 | 0.0 | | REG1A | P05451 | 0.0 | 0.0 | | QPCT |
Q16769 | 0.0 | 0.0 | | FCN2 | Q15485 | 0.0 | 0.0 | | FETUB | Q9UGM5 | 0.0
| 0.0 | | CES1 | P23141 | 0.0 | 0.0 | | CRTAC1 | Q9NQ79 | 0.0 | 0.0 | |
TCN2 | P20062 | 0.0 | 0.0 | | PRSS2 | P07478 | 0.0 | 0.0 | | ICAM3 |
P32942 | 0.0 | 0.0 | | SAA4 | P35542 | 0.0 | 0.0 | | CNDP1 | Q96KN2 | 0.0
| 0.0 | | FCGR2A | P12318 | 0.0 | 0.0 | | NRP1 | O14786 | 0.0 | 0.0 | |
EFEMP1 | Q12805 | 0.0 | 0.0 | | TIMD4 | Q96H15 | 0.0 | 0.0 | | FAP# |
Q12884 | 0.0 | 0.0 | | TIE1 | P35590 | 0.0 | 0.0 | | THBS4 | P35443 | 0.0
| 0.0 | | F7 | P08709 | 0.0 | 0.0 | | GP1BA | P07359 | 0.0 | 0.0 | | LYVE1
| Q9Y5Y7 | 0.0 | 0.0 | | CA3 | P07451 | 0.0 | 0.0 | | TGFBR3 | Q03167 |
0.0 | 0.0 | | DEFA1 | P59665 | 0.0 | 0.0 | | CD59 | P13987 | 0.0 | 0.0 | |
APOM | O95445 | 0.0 | 0.0 | | OSMR | Q99650 | 0.0 | 0.0 | | LILRB2 |
Q8N423 | 0.0 | 0.0 | | UMOD | P07911 | 0.0 | 0.0 | | CCL18 | P55774 | 0.0
| 0.0 | | COL18A1 | P39060 | 0.0 | 0.0 | | LCN2 | P80188 | 0.0 | 0.0 | |
KIT | P10721 | 0.0 | 0.0 | | C1QTNF1 | Q9BXJ1 | 0.0 | 0.0 | | AOC3 |
Q16853 | 0.0 | 0.0 | | GAS6 | Q14393 | 0.0 | 0.0 | | IGLC2 | P0DOY2 | 0.0
| 0.0 | | PLA2G7 | Q13093 | 0.0 | 0.0 | | TNXB | P22105 | 0.0 | 0.0 | |
MFAP5# | Q13361 | 0.0 | 0.0 | | VASN | Q6EMK4 | 0.0 | 0.0 | | LILRB5 |
O75023 | 0.0 | 0.0 | | C2 | P06681 | 0.0 | 0.0 | Legend: #<20% of NPX
values above panel’s estimated limit of detection. **Sharing/access
Information:** Links to other publicly accessible locations of the data:
None Was data derived from another source? No