Introduction

Since some features in the more pre-trained or fine-tuned concept model are correlated to patient CPI response status, among the 45 pre-trained features, we found that the following features are highly correlated features, such as CD8_Tcell,CD4_Tcell, Cytotoxic_Tcell,Exhausted_Tcell, Macrophage, NKcell, TMB, PLFcell, Memory_Tcell, IFNg_pathway, Monocyte, Myeloid, etc.

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In this example, we demonstrate how to extract features based on pretrainer or finetuner for building a logistic regression model

from compass.utils import plot_embed_with_label
from compass import PreTrainer, FineTuner, loadcompass #, get_minmal_epoch
from compass.utils import plot_embed_with_label, plot_performance, score2
from compass.tokenizer import CANCER_CODE
import os
from tqdm import tqdm
from itertools import chain
import pandas as pd
import numpy as np
import random, torch
import matplotlib.pyplot as plt
import seaborn as sns
sns.set(style = 'white', font_scale=1.3)
import warnings
warnings.filterwarnings("ignore")

def onehot(S):
    assert type(S) == pd.Series, 'Input type should be pd.Series'
    dfd = pd.get_dummies(S, dummy_na=True)
    nanidx = dfd[dfd[np.nan].astype(bool)].index
    dfd.loc[nanidx, :] = np.nan
    dfd = dfd.drop(columns=[np.nan])*1.
    cols = dfd.sum().sort_values(ascending=False).index.tolist()
    dfd = dfd[cols]
    return dfd

Extract the features to be used in a LGR model

## load model
model = loadcompass('https://www.immuno-compass.com/download/model/pretrainer.pt')

## read data
df_label = pd.read_pickle('./tmpignore/ITRP.PATIENT.TABLE')
df_tpm = pd.read_pickle('./tmpignore/ITRP.TPM.TABLE')

df_label = df_label[df_label.cohort == 'IMmotion150']
df_tpm = df_tpm.loc[df_label.index]
dfcx = df_label.cancer_type.map(CANCER_CODE).to_frame('cancer_code').join(df_tpm)
df_task = onehot(df_label.loc[dfcx.index].response_label)

dfcx.head()

	cancer_code	A1BG	A1CF	A2M	A2ML1	A4GALT	A4GNT	AAAS	AACS	AADAC	...	ZWILCH	ZWINT	ZXDA	ZXDB	ZXDC	ZYG11A	ZYG11B	ZYX	ZZEF1	ZZZ3
Index
IMmotion150-p01155-ar-28f34	11	0.000000	0.098867	569.650898	0.000000	12.308948	0.018497	63.707358	14.434985	66.125180	...	6.389789	5.303300	5.051903	4.589033	10.261535	0.288717	25.858985	56.947976	42.042863	10.116892
IMmotion150-p03058-ar-c2dad	11	0.254285	12.912481	2219.543961	0.130203	17.130387	0.164449	63.061299	9.498081	1.242164	...	11.407857	1.783814	4.070043	3.850006	7.302152	1.027050	26.337602	70.748166	47.674605	11.859255
IMmotion150-p03363-ar-a74ac	11	1.738725	21.307989	2022.470916	0.000000	39.377504	0.000000	102.279939	8.651851	0.000000	...	5.026485	3.233093	6.573876	4.301948	11.420510	0.136894	20.903173	66.970426	42.152788	5.789718
IMmotion150-p03418-ar-d867a	11	256.478618	78.939864	1504.517253	0.008377	14.008435	0.000000	85.648168	8.166077	63.876737	...	7.095447	7.343206	4.634568	5.377463	13.105987	0.545127	18.968981	46.839687	36.639318	9.111185
IMmotion150-p03665-ar-04d83	11	2.428848	1.952094	945.986656	0.000000	10.977868	0.112258	75.503642	15.587454	0.208317	...	9.394811	5.791613	5.701962	5.184023	9.787591	0.146017	17.989702	100.555068	47.372759	7.922010

5 rows × 15673 columns

## Extract the features, including geneset features and celltype features
dfg, dfc = model.extract(dfcx, batch_size = 16)

100%|##########| 11/11 [00:02<00:00,  5.19it/s]

## all of the 45 borader features
print(dfc.columns)

Index(['CANCER', 'Adipocyte', 'Apoptosis_pathway', 'Bcell', 'CD4_Tcell',
       'CD8_Tcell', 'CPI_Response', 'CPI_effect', 'Cytokine_chemokine',
       'Cytotoxic_Tcell', 'Endothelial', 'Epithelial', 'Erythrocyte',
       'Exhausted_Tcell', 'Fibroblast', 'Granulocyte', 'Hepatocyte',
       'IFNg_pathway', 'Immune_checkpoint', 'Immune_score',
       'Innate_lymphoid_cell', 'Macrophage', 'Mast', 'Memory_Tcell',
       'Mesothelial', 'Monocyte', 'Myeloid', 'NKcell', 'Naive_Tcell',
       'Neutrophil', 'OS_effect', 'PLFcell', 'Pancreatic', 'Platelet',
       'Pneumocyte', 'Stem', 'Stroma', 'TGFb_pathway', 'TLS', 'TMB',
       'Tcell_exclusion', 'Tcell_general', 'Treg', 'cDC', 'pDC', 'Reference'],
      dtype='object')

selected_features =  ['CD8_Tcell', 'CD4_Tcell', 'Cytotoxic_Tcell', 
                      'Exhausted_Tcell', 'Macrophage', 'NKcell', 'TMB', 'CPI_effect',
                      'PLFcell', 'Memory_Tcell', 'Monocyte', 'Myeloid' ]

Build a LGR model

from sklearn.model_selection import GridSearchCV, LeaveOneOut
from sklearn.preprocessing import StandardScaler
from sklearn.linear_model import LogisticRegression

cohort_dfx = dfc[selected_features]
cohort_dfy = df_task['R']

# split train, test
test_idx = df_label.groupby('response_label').sample(frac=0.2, random_state=42).index
train_idx = df_label.index.difference(test_idx)

train_X = cohort_dfx.loc[train_idx]
train_y = cohort_dfy.loc[train_idx]
test_X = cohort_dfx.loc[test_idx]    
test_y = cohort_dfy.loc[test_idx]

print(len(train_idx), len(test_idx))

132 33

param_grid = {'penalty':['l2'], 'max_iter':[int(1e10)], 'solver':['lbfgs'],
              'C':np.arange(0.1, 10, 0.1), 'class_weight':['balanced'] }

lgr_model = LogisticRegression()
gcv = GridSearchCV(lgr_model, param_grid=param_grid, 
                   scoring='roc_auc', cv=5, n_jobs=-1).fit(train_X, train_y)

Make prediction based on the best model

pred_prob = gcv.best_estimator_.predict_proba(test_X)
pred_testy = pd.DataFrame(pred_prob, index = test_X.index)
y_true = test_y
y_prob = pred_testy[1]
y_pred = pred_testy.idxmax(axis=1)

fig = plot_performance(y_true, y_prob, y_pred)

Discussions

In this example, we show how to build a LGR model based on the conceptor features. In practical, you can also extract the features from a finetuned model insead of the pretrained model