Inflammatory Cytokines: TNFα, IL-1β, IL-6 and IL-8 in Pulmonary Hypertension of Sickle Cell Disease.

Background: Although pulmonary hypertension (PHT) is a common complication in patients with sickle cell disease (SCD), the rate of development of PHT and the factors that affect disease progression are unknown.

Objectives: To evaluate the plasma levels of cytokines in SCD comparing with healthy subjects and to find out if there is a relationship among cytokines and PHT.

Patients and methods: Dosage of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFα), interleukin-8 (IL-8) and interleukin-1 beta (IL-1β) had been evaluated in 107 steady-state sickle cell patients, from the UNIFESP/EPM and College of Medical Sciences of the Santa Casa de Misericórdia, and in 108 blood donors. The presence of PHT was evaluated in sickle cell patients by transthoracic Doppler echocardiogram and the results were associated with age, hemoglobin and fetal hemoglobin, lactic dehydrogenase and cytokines levels.

Results: The presence of PHT was significantly related with age, low hemoglobin and high lactic dehydrogenase levels. There were no difference of plasma levels of IL-6, IL-1β and TNFα between patients and controls. The IL-8 levels were predominantly higher in patients than in controls (p=0.0001). Among patients with SCD, IL-8 levels were significantly higher in those with PHT (p=0.02). In addition, increased levels of IL-8 (>95^th percentile of the control group) were detected in 33.3% in patients with PHT in comparison with 10.8% in those without (OR: 4.1; 95%CI 1.3–12.7).

Conclusion: These results indicate that age, hemoglobin, lactic dehydrogenase levels, and elevated levels of IL-8 could be risk factors of PHT in SCD. However a larger study with SCD patients with PHT is required to clarify this question. (Funded by Fapesp 04/04498–4).