Introduction: This study aimed to assess programmed death-1 (PD-1) and programmed death ligand-1 (PDL-1) expression in newly diagnosed pediatric cases of acute B-lymphoblastic leukemia (B-ALL) and at 6 months of treatment and to explore their value as biomarkers.

Methods: Fifty newly diagnosed B-ALL patients and 30 controls were recruited. Bone marrow samples or peripheral blood were obtained from children at diagnosis and 6 months after cytotoxic therapy. Flow cytometric analysis of obtained samples was done and the PD-1, PDL-1, and CD3 (cluster of differentiation) expressions were recorded.

Results: Percentages of PD-1, PDL-1, and CD3 in the control and B-ALL groups at initial presentation were 7.9% ± 2.8% vs. 16.45% ± 7.7% (p = 0.023), 8.6% ± 3.4% vs. 19.05% ± 13.7% (p < 0.001), and 30.8% ± 1.2% vs. 11.05% ± 7.3% (p < 0.001), respectively. CD3 expression increased significantly at 6 months; PD-1 and PDL-1 expression showed insignificant decrease from initial presentation. There was a negative correlation between PD-1 and HB level (p = 0.03) and a positive correlation between PD-1 and PDL-1 at 6 months of treatment (p = 0.002). Remission rates increased significantly with the decrease of PD-1and PDL-1.

Conclusion: Initially, PD-1 and PDL-1 were higher in patients than in controls and decreased 6 months after treatment. PD-1 and PDL-1 expression was associated with increased remission rates, implicating that modulation of PD-1 and PDL-1 expression may be a therapeutic approach for B-ALL. Moreover, this study created a new method for the assessment of PD-1 and PDL-1 in B-ALL.

Clinical trial: Trial Registration: NCT05428111.

No doubt, the value of pets (mainly cats, and/or dogs) extends far beyond their adorable
appearances, boosting the mental health to fostering deeper human connections. Nevertheless,
they are risky to the owners mainly babies, and children via bites and scratches, falls from
being knocked over by the pet, & choking on pet toys or food. Besides, allergies or asthma
caused by pet's fur, saliva, feathers or skin flakes (dandruff) zoonotic infectious diseases
usually from poo, food, water or litter trays. This reviews the several concepts that have taken
shape in recent decades and discuss how these apply to common patient concerns.
Key words: Pets, Indoors, Adorable, daily care, Allergies, Zoonotic infectious diseases.