Emergency red cell exchange for the management of acute complications in sickle cell disease: Automated versus manual.

BACKGROUND: Red blood cell exchange is the cornerstone of the management for acute complications of sickle cell disease. It improves anaemia and improvesperipheral tissue oxygen delivery while at the same time reduces the proportion of circulating sickle erythrocytes. Even though automated red cell exchange is very effective in rapidly lowering the Hb S level, 24-h availability is currently not feasible for most specialist centres including our own. OBJECTIVE: Here, we describe our experience using both automated and manual red cell exchange for the management of acute sickle cell complications. METHODS: Eighty-six such episodes have been recorded between June 2011 and June 2022 comprising of 68 episodes of automated and 18 episodes of manual red cell exchange. RESULTS: The post procedure Hb S/S + C level was 18% after automated and 36% after manual red cell exchange. The platelet count dropped by 41% and 21% after automated and manual red cell exchange respectively. The clinical outcomes including need for organ support, duration of stay in the intensive care unit and overall length of hospitalisation was comparable between the two groups. CONCLUSION: In our experience, manual red cell exchange is a safe and effective alternative to an automated procedure that can be used while specialist centres are building up their capacity to offer automated red cell exchange for all patients requiring the intervention.

Rate of Dental Extractions in Patients with Sickle Cell Disease.

BACKGROUND: Sickle cell disease is an inherited disorder associated with chronic haemolysis and anaemia, recurrent episodes of pain and potentially multisystem end-organ damage. A lot less is known about the dental health of these patients. AIMS: To explore the incidence of severe dental disease leading to dental extraction in our sickle cell population. PATIENT/METHODS: We undertook an audit looking at the rate of dental extractions, as a composite marker of severe dental disease, among sickle cell patients over a 3-month period. The patients were unselected and approached during routine assessments. We analysed both clinical and laboratory data to look for possible associations between dental disease and sickle cell characteristics. RESULTS: 177 patients were interviewed between February 2022 and April 2022. Overall, 71% of the patients had at least one dental extraction with a median number of teeth extracted of three and a median age at first extraction of 26. More than half of the patients stated that they do not have regular dental check-ups. There were no significant associations with the severity of sickle cell phenotype, baseline Hb or markers of haemolysis. CONCLUSION: A large number of patients with sickle cell disease require dental extractions at a relatively young age. The lack of any correlation with disease severity suggests that poor engagement with dental services and the underestimation of the importance of dental health are the main factors behind the increased prevalence of severe dental disease. Actively enquiring about dental problems should be part of any routine consultation with these patients, both in primary and specialist care.

Therapeutic plasma exchange in the management of acute complications of sickle cell disease: A single centre experience.

Sickle cell disease results in systemic inflammation even at steady state and this is accentuated during acute crises. The plasma of affected patients contains several proinflammatory cytokines as well as adhesion molecules and prothrombotic factors. This environment promotes further red cell sickling while many of these substances can cause direct tissue toxicity and end-organ damage. Even though red cell transfusion, whether simple or exchange, is the mainstay of treatment of severe acute complications, addition of therapeutic plasma exchange could potentially provide additional benefit by removing such harmful substances. Here, we describe two cases where therapeutic plasma exchange was used. The first involved a patient with the acute chest syndrome who despite adequate red cell exchange remained significantly hypoxic and in severe pain. We therefore proceeded to perform plasma exchange; this led to rapid clinical improvement and resolution of his symptoms. The second case involved a patient with intractable chest wall pain and impending acute chest syndrome; this patient also had a past history of hyperhaemolysis. The patient underwent therapeutic plasma exchange with very rapid resolution of the pain, avoidance of any respiratory deterioration and full recovery. We also give a brief summary of our previous experience using plasma exchange in patients with sickle cell disease. Plasma exchange was well tolerated with no adverse events in all cases we have treated, led to rapid resolution of pain irrespective of primary indication and in the majority of cases to a favourable clinical outcome.

Comparison of proton and electron radiation effects on biological responses in liver, spleen and blood.

PURPOSE: To determine whether differences exist between proton and electron radiations on biological responses after total-body exposure. MATERIALS AND METHODS: ICR mice (n=45) were irradiated to 2 Gray (Gy) using fully modulated 70 MeV protons (0.5 Gy/min) and 21 MeV electrons (3 Gy/min). At 36 h post-irradiation liver gene expression, white blood cell (WBC), natural killer (NK) cell and other analyses were performed. RESULTS: Oxidative stress-related gene expression patterns were strikingly different for irradiated groups compared to 0 Gy (P<0.05). Proton radiation up-regulated 15 genes (Ctsb, Dnm2, Gpx5, Il19, Il22, Kif9, Lpo, Nox4, Park7, Prdx4, Prdx6, Rag2, Sod3, Srxn1, Xpa) and down-regulated 2 genes (Apoe, Prdx1). After electron irradiation, 20 genes were up-regulated (Aass, Ctsb, Dnm2, Gpx1, Gpx4, Gpx5, Gpx6, Gstk1, Il22, Kif9, Lpo, Nox4, Park7, Prdx3, Prdx4, Prdx5, Rag2, Sod1, Txnrd3, Xpa) and 1 was down-regulated (Mpp4). Of the modified genes, only 11 were common to both forms of radiation. Comparison between the two irradiated groups showed that electrons significantly up-regulated three genes (Gstk1, Prdx3, Scd1). Numbers of WBC and major leukocyte types were low in the irradiated groups (P<0.001 vs. 0 Gy). Hemoglobin and platelet counts were low in the electron-irradiated group (P<0.05 vs. 0 Gy). However, spleens from electron-irradiated mice had higher WBC and lymphocyte counts, as well as enhanced NK cell cytotoxicity, compared to animals exposed to protons (P<0.05). There were no differences between the two irradiated groups in body mass, organ masses, and other assessed parameters, although some differences were noted compared to 0 Gy. CONCLUSION: Collectively, the data demonstrate that at least some biological effects induced by electrons may not be directly extrapolated to protons.