Clinical and Laboratory Features of Sickle Cell Disease S/D Punjab: Impact of HbF and Hydroxyurea.

Background: Sickle cell disease (SCD) is a major public health issue worldwide with high morbidity and mortality. SCD SD Punjab is the third most common genotype of SCD in Oman and is associated with several serious complications. The aim of the study is to establish the clinical and laboratory features of SCD patients with SD double heterozygotes and study the impact of haemoglobin F, hydroxyurea, and other modulators on the disease severity.

Methods: We analysed the electronic medical records of 52 consecutive SCD patients who were diagnosed as double heterozygote SD Punjab between 2006 and 2022. The study was approved by the local medical research and ethics committee. The data captured included SCD-related complications and current clinical and laboratory indices. Data from other studies on other SCD genotypes were used as historical controls.

Results: 52 patients (31 males, 21 females) who formed this cohort had a median age of 32 years with an interquartile range (IQR) of 21-39.8 years. 37(71.2%) had <3 VOC per year, whereas 15 (28.8%) patients had ≥3 vasooclusive (VOC) episodes per year. SCD-related complications included Acute Chest Syndrome (ACS) (48%), Gall stones (26.9%), Avascular necrosis (AVN) (28.8%), Stroke (13.5%) and splenic sequestration (7.7%), whereas 5 (9.6%) patients of this cohort died. Surgical and Autosplenectomy were seen in 18 (34.6%). These findings were similar to other SCD genotypes in this community. 19 (57.6%) were taking Hydroxyurea (HU) amongst the 33 patients who were prescribed HU. Haematological parameters showed a median (IQR) Hb (g/dl), MCV (fl), Retic count (%), WBC count(×10⁹/L) and Platelet count(×10⁹/L) of 9.7 (8.5-11.3), 74.9 (68.4-79.8), 4 (3.2-5.7), 9.9 (8.1-12.6) and 309 (239-428) respectively. The haemoglobin electrophoresis showed an elevated HbF, whereas serum bilirubin and LDH were elevated amongst the biochemical parameters. The use of hydroxyurea showed no impact on VOC, ACS, AVN, Stroke or mortality.

Conclusion: SD Punjab is the third most common SCD genotype in Oman and was associated with recurrent VOC, ACS, AVN, and gall stones comparable to other SCD genotypes. Patients with > 3 VOC/year had significantly increased incidence of Stroke, AVN, and gallstones. However, HU was not associated with improved prognosis and better survival in this cohort of patients.