Systemic Effects of Photobiomodulation on Blood Components in the Treatment of Community-Acquired Pneumonia.

Background: The analysis of the complete blood count (CBC) of patients with community-acquired pneumonia (CAP) is an essential practice both for diagnosing the disease and for evaluating the patient's clinical evolution. It is proposed in the present study to analyze the hematological alterations resulting from photobiostimulation using near-infrared light-emitting diodes (LEDs) in patients with CAP. Methods: This was a clinical, prospective, blinded, and descriptive longitudinal study that involved 21 patients undergoing CAP treatment who were divided into two groups: LED, 11 patients who were treated with infrared LED and conventional treatment; and CON (control), 10 patients who received only conventional treatment (antibiotic therapy and physiotherapy). Physiotherapy was applied before LED irradiation in the LED group. The patients' CBCs were obtained before and after treatment, and erythrocyte counts, hemoglobin and hematocrit concentrations, and leukocyte and platelet counts were assessed. The phototherapy was performed with a vest with an array of 300 LEDs (940 nm) mounted on an area of 36 × 58 cm and positioned in the patient's anterior thoracic and abdominal regions. The total power was 6 W, with 15 min of irradiation time. The patients were treated daily for seven consecutive days. Statistical analyses of the intra- and intergroups of CBC data were done using Student's t -test and one-way ANOVA (analysis of variance), respectively, both at the significance level of α = 0.05. Results: There was a statistically significant recovery difference after treatment in the LED group compared with the CON group for erythrocytes, hemoglobin, leukocytes, segmented and band neutrophils, lymphocytes, and monocytes ( p  < 0.05). The greatest differences between the LED and CON groups were lymphocyte count reduction (60% vs. 16%), erythrocyte increase (86% vs. 35%), and leukocyte reduction (28% vs. 15%). Conclusions: The hematologic components of CAP patients recovered their normal values faster with conventional treatment associated with infrared LED therapy, thus indicating greater treatment efficiency when compared with the conventional therapy. This study was registered with the Brazilian Registry of Clinical Trials (ReBeC) under Universal Trial Number (UTN) U1111-1229-1296 (2019/06/05).