Impact of COVID-19 on vasooclusive crisis in patients with sickle cell anaemia.

OBJECTIVES: The study aimed to assess COVID-19 impact on the morbidity and mortality of vasooclusive crisis (VOC) in sickle cell anaemia (SCA) patients. METHODS: A prospective cohort study of 100 SCA patients; 50 with COVID-19 (COVID group) and 50 without (non-COVID group). All patients signed written informed consent. RESULTS: The COVID group had a significantly higher VOC episode median per year; 3 (IQR,1-6) vs 2 (IQR,2-12) (P < 0.05). The need for hospitalisation was similar in both groups. The non-COVID group had more history of culture-proven infection (P = 0.05). The COVID-group had more osteonecrosis (P < 0.05), splenic sequestration, splenomegaly and hepatic crisis (P = 0.05, 0.006, 0.02; respectively) and significantly higher (P < 0.05) symptoms of fever, cough, fatigue, abdominal pain and anosmia. Mean haemoglobin, lymphocyte subset, platelets, and reticulocytes were reduced in both groups, while lactate dehydrogenase and ferritin levels were significantly elevated. In the COVID group, the rise in white blood cell count, reticulocyte percentage, platelets and ferritin was subdued (P < 0.05). Two patients in the COVID group and 3 in the non-COVID group died; there was no statistically significant difference in mortality. CONCLUSIONS: Although COVID-19 may have triggered the onset of VOC, it did not significantly influence VOC-related morbidity or mortality in this SCA cohort.

The Use of HPLC as a Tool for Neonatal Cord Blood Screening of haemoglobinopathy: A Validation Study.

BACKGROUND: Newborn cord blood screening identifies infants with underlying haemoglobinopathies before they develop the characteristic symptoms or sequelae. AIMS: This study was performed to validate the interpretation high-performance chromatography (HPLC) along with complete blood count (CBC) results as a tool for universal neonatal screening of hemoglobin disorders in Oman. METHODS: HPLC and CBC data on subjects who participated in the National Neonatal screening program at birth were obtained from archival records. The results recorded at birth were compared with a second study performed on the same subjects, after approval from the local medical research and ethics committee. RESULTS: Only 290 subjects from amongst the original cohort of 3740 newborns could be recalled between April 2010 to March 2011, to repeat HPLC and CBC, as well as perform confirmatory DNA studies, wherever necessary. All these subjects had been documented to show an initial abnormal result. 31 cases who had no HbA at birth on HPLC were confirmed as either homozygous ß-thalassaemia major (n=5 subjects) or homozygous sickle cell anemia (n=26 subjects) by appropriate DNA analysis. Additionally, amongst 151 subjects, 72 subjects were studied in the initial study by Hb Bart's quantitation using the alpha thalassaemia short program at birth. In this cohort, 42 subjects with Hb Bart's >1% at birth could be confirmed as having either deletional or non-deletional thalassaemia by GAP PCR studies. No case of HbH was detected in this cohort. Further, carrier status for structural hemoglobin variants (HbS, HbC, HbD, HbE) (n=67) and beta thalassaemia allele with low HbA at birth (n=29 out of 41) were confirmed by relevant molecular studies. CONCLUSIONS: The study validated the earlier observation by 100% concordance with the results of CBC and HPLC. Presence of Hb Bart's at birth does not always mean the presence of alpha thalassemia, as subjects with Hb Bart's below 1% by quantitation, were shown to be normal by molecular studies.

Potential pitfalls in the diagnosis of Hb Handsworth in areas with high prevalence of HbS.

Hb Handsworth is a rare α-globin structural variant caused by a missense mutation either on the α2 or α1-globin gene (HBA2 or HBA1: c.55G>C, p.Gly18Arg). This variant might be erroneously diagnosed as HbS unless secondary confirmative tests are carried out. We encountered a child with a prominent peak eluting in the 'S' window on high-performance liquid chromatography (HPLC). Sickle solubility test, gel electrophoresis, and selective direct nucleotide sequencing of α1, α2, and ß globin genes were performed on the patient's sample. In addition, previous HPLC results on a cord blood sample were retrieved. Sickle solubility test was negative. Gel electrophoresis revealed a band migrating at the S region with an extra faint band seen on acid gel electrophoresis. Molecular analysis of α2 globin gene revealed heterozygous state of Hb Handsworth. Hb Handsworth is a rare variant that can mimic HbS on HPLC. Failure to recognize this rare variant in regions where HbS is highly prevalent may result in serious misdiagnosis and subsequent incorrect genetic counseling.