A Monocentric, Prospective, Observational Study On Vaso-Occlusive Crisis (VOC) in Adult Sickle-Cell Disease (SCD).

VOC, the most common manifestation of SCD, is the first cause of death, particularly when complicated by an acute chest syndrome (ACS) or multiorgan failure.^1,2 Vichinsky et al³ found that nearly half their patients included for ACS were initially hospitalized for VOC. However, no data are available on follow-up differences between patients hospitalized for uncomplicated VOC and those who will develop ACS. We report the preliminary analytical results of blood samples drawn on days 1, 2 and 4 of hospitalization for VOC and at steady state from patients enrolled in the more comprehensive PRESEV study.

This prospective, monocenter, observational trial included homozygous SCD patients, ≥18 years old with severe VOC requiring admission to our university hospital's Adult Sickle-Cell Referral Center. This study was conducted in accordance with the Declaration of Helsinki principles, Good Clinical Practice guidelines, and local laws and regulations. Severe VOC was defined as pain or tenderness, affecting at least 1 part of the body, e.g. limbs, ribs, sternum, head (skull), spine and/or pelvis, that required opioids and was not attributable to other causes. ACS was defined as the association of 2 criteria among chest pain, radiologic infiltrate and auscultatory abnormality. Patients could be enrolled in the trial more than once if their hospitalizations were separated by ≥1 months. Exclusion criteria were: ACS on day of inclusion, pregnancy, hospitalization for >24 h, chronic blood-exchange transfusion (BET), transfusion impossibility, severe complication requiring transfusion at admission, proven sepsis, surgery <15 days earlier. Patients were divided into 2 groups: VOC (without ACS) and those with secondary ACS; all were treated according to the French guidelines.⁴ Steady state was defined as a consultation ³1 months after an acute clinical event (VOC, infection, ACS, or any other clinical event requiring hospitalization and/or blood transfusion) and ³3 months after last blood transfusion. Results are expressed as mean±SD.

Among the 147 patients satisfying inclusion criteria: 38 (26%) developed an ACS on hospital day 3.2±3; and 22 (15%) received acute BET or transfusion, including 18 with ACS (47% of ACS), 3 for prolonged VOC (including 1 with cytomegalovirus infection) and 1 for pure red-cell aplasia. For the VOC and ACS groups, respectively, mean ages were comparable (30.4±7.2 and 30.6±6.9 years), as were F/M sex ratios (0.7 and 0.8). No patient died. Their blood-parameter results are given in the Table

Bili Tand D: total and direct bilirubinemia; GGT, Gamma-glutamyl transpeptidase; CPK: creatinine phosphokinase. *ANOVA for repeated measures: difference between VOC and ACS curves, and evolution over time.

These trial results provide new insights into very early evolution blood values for SCD patients hospitalized for VOC and those among them developing ACS, as compared to their steady-state values. It confirms the different evolutions in hemoglobin, leukocytes and LDH between VOC and secondary ACS, and shows muscle and liver involvement.

No relevant conflicts of interest to declare.