Promise of Composite Pain Index as a single pain outcome for sickle cell disease across the lifespan

BACKGROUND

This study aimed to validate a Composite Pain Index (CPI) as a single pain outcome measure for sickle cell disease (SCD) across the lifespan from 8 years of age.

PROCEDURE

This prospective, cross-sectional study included 55 participants with SCD who completed the PAINReportIt tool and Adolescent Pediatric Pain Tool (APPT) in random order during outpatient visits to derive respective CPI scores for comparison.

RESULTS

Of the 55 participants with SCD, 46 (84%) had HgbSS, eight (15%) HgbSC, and one (2%) HgbSβ0+. The mean age of all participants was 17.5 ± 2.6 years, and 28 (51%) were female, 52 (95%) were Black, 42 (98%) were non-Hispanic, and 39 (71%) had a ninth grade or higher education. Correlation analyses between the APPT and PAINReportIt revealed positive associations for the number of pain sites (r = .57, p < .001), pain intensity (r = .46, p < .001), pain quality (r = .74, p < .001), and pain pattern (r = .34, p = .01). Patients' mean CPI scores derived from the PAINReportIt was slightly higher than the APPT; 34.2 (SD = 14.7) and 30.0 (SD = 19.0), respectively. Regression analyses showed that the APPT CPI significantly predicted the PAINReportIt CPI (B = .497, t(53) = 6.051, p < .001). This finding holds true even when accounting for the order of measurement or patient's age.

CONCLUSION

The initial validation of CPI as a single pain outcome measure represents a significant advancement in pain assessment for SCD. Further validation is warranted for the CPI as a measure is for both clinicians and researchers to enable longitudinal pain assessment from age 8 years across the lifespan as children age into adult care.

Prevalence of pain-related single nucleotide polymorphisms in patients of African origin with sickle cell disease

BACKGROUND

Prospective pain genetics research is hindered by a lack of data on the prevalence of polymorphisms in pain-relevant genes for patients with sickle cell disease (SCD). For African-Americans in general, limited information is available in public databases.

METHODS

We prioritized and examined the genotype and allele frequencies of 115 SNPs from 49 candidate pain genes in 199 adult African-Americans and pediatric patients of African origin with SCD. Analyses were performed and compared with available data from public databases.

RESULTS

Genotype and allele frequencies of a number of SNPs were found to be different between our cohort and those from the databases and between adult and pediatric subjects.

CONCLUSION

As pain therapy is inadequate in a significant percentage of patients with SCD, candidate pain genetic studies may aid in designing precision pain medicine. We provide prevalence data as a reference for prospective genetic studies in this population.

Hydroxyurea therapy for priapism prevention and erectile function recovery in sickle cell disease: a case report and review of the literature

Prolonged ischemic priapism in patients with sickling hemoglobinopathies is a urologic emergency requiring immediate intervention to avoid irreversible anoxic penile injury, corporal fibrosis, and erectile dysfunction. Therapeutic options, however, are limited and often ineffective. Here, we report recovery of erectile function with hydroxyurea therapy in an adolescent with hemoglobin SS following a prolonged episode of priapism and subsequent severe erectile dysfunction. This case suggests a potential role of hydroxyurea in reversing end organ damage in patients with hemoglobin SS and also supports basic science work indicating involvement of the NO-dependent pathway in the pathogenesis of sickle cell disease-associated priapism.

Alloimmunization in sickle cell anemia in the era of extended red cell typing

BACKGROUND

Red blood cell (RBC) transfusion remains an essential part of the management of patients with sickle cell disease (SCD). Alloimmunization is a major complication of transfusions. Extended RBC typing is advocated as a means to reduce alloimmunization in SCD. Our goal was to assess alloimmunization among individuals with SCD at our center since implementing extended RBC typing.

MATERIALS AND METHODS

We reviewed electronic medical records of all patients with SCD (N = 641) in our comprehensive SCD Program to determine transfusion histories. Cross-referencing with our blood bank database, we extracted data such as antibodies identified, detection date and genotyping in specific cases. Transfusion sources were determined for those with C, E, and Kell antibodies.

RESULTS

Of 180 patients transfused from 2002 to 2011, 26 developed at least one new antibody. The majority of alloimmunized patients (14/26) received episodic transfusions only. The most common antibodies formed were against C and E antigens. Of the 16 patients who developed C, E, Kell antibodies, nine had one or more documented transfusions at an outside hospital. Five patients had Rh variants undetectable on routine phenotyping including two novel e alleles related to ceAR and ce(S)(733G).

CONCLUSION

Despite extended RBC typing, alloimmunization may still occur due to RBC variants that are not detected on routine screening and transfusions at institutions where extended RBC typing is not done. Extended RBC typing should be the standard of care for patients with SCD. Prospective genotyping may reduce allosensitization to rare variants not detected on routine screening.

Adolescent pediatric pain tool for multidimensional measurement of pain in children and adolescents

Very few multidimensional tools are available for measurement of pain in children and adolescents. We critically reviewed the scientific literature to examine the psychometrics and utility of the Adolescent Pediatric Pain Tool (APPT), a multidimensional self-report tool that evaluates the intensity, location, and quality (including affective, evaluative, sensory, and temporal) dimensions of pain. The APPT is available in English and Spanish for children and adolescents, and was modeled after the McGill Pain Questionnaire in adults. We found good evidence for construct validity, reliability, and sensitivity of the APPT for the measurement of pediatric pain. The APPT was used to measure pain in children with different conditions, such as cancer, sickle cell disease, orthopedic, traumatic injuries, and allergy testing. Although the APPT was designed to assess the multiple dimensions of pain, the majority of the reports included results only for the intensity ratings. Unlike the numerical and pediatric faces rating scales, which are widely used in clinical practice and research, the APPT is not limited to the single dimension of pain intensity. It measures multiple dimensions, and may be able to discriminate between nociceptive and neuropathic pain. The APPT is one of a few multidimensional pain measures that can help to advance the science of pediatric pain and its management. When the APPT is used in practice or research, the multiple dimensions of pain may be characterized and compared in different painful conditions. It may guide the use of multimodal interventions in children and adolescents with a variety of pain conditions.

Opioid patient controlled analgesia use during the initial experience with the IMPROVE PCA trial: a phase III analgesic trial for hospitalized sickle cell patients with painful episodes

Opioid analgesics administered by patient-controlled analgesia (PCA)are frequently used for pain relief in children and adults with sickle cell disease (SCD) hospitalized for persistent vaso-occlusive pain, but optimum opioid dosing is not known. To better define PCA dosing recommendations,a multi-center phase III clinical trial was conducted comparing two alternative opioid PCA dosing strategies (HDLI—higher demand dose with low constant infusion or LDHI—lower demand dose and higher constant infusion) in 38 subjects who completed randomization prior to trial closure. Total opioid utilization (morphine equivalents,mg/kg) in 22 adults was 11.6 ± 2.6 and 4.7 ± 0.9 in the HDLI andin the LDHI arms, respectively, and in 12 children it was 3.7 ± 1.0 and 5.8 ± 2.2, respectively. Opioid-related symptoms were mild and similar in both PCA arms (mean daily opioid symptom intensity score: HDLI0.9 ± 0.1, LDHI 0.9 ± 0.2). The slow enrollment and early study termination limited conclusions regarding superiority of either treatment regimen. This study adds to our understanding of opioid PCA usage in SCD. Future clinical trial protocol designs for opioid PCA may need to consider potential differences between adults and children in PCA usage.

Sickle cell disease: an opportunity for palliative care across the life span

Sickle cell disease is a chronic illness that affects patients physically and emotionally and can do so at an early age. An ecological model of palliative care that involves improved communication among the health care team, patients, and their families can be beneficial. Open and honest communication regarding advance care planning, disease management, relief of pain and other symptoms, and bereavement and grief are all important for the patient, family, and health care team. Given the multiple acute and chronic complications of sickle cell disease, an approach to care that is holistic and comprehensive may help to improve a patient's biologic function and the perceived health, functional status, and quality of life of the patient and family.

Apolipoprotein A-I and serum amyloid A plasma levels are biomarkers of acute painful episodes in patients with sickle cell disease

BACKGROUND

Acute painful episodes are the clinical hallmark of sickle cell disease and have been linked to morbidity and mortality in the sickle cell population.

DESIGN AND METHODS

We undertook exploratory proteomic studies on paired plasma samples collected from a cohort of 26 adult sickle cell patients during steady state and on the first day of an acute painful episode. We screened for changes in abundance of specific protein peaks via surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF MS), and confirmed the identify of candidate protein peaks by specific immunoassays.

RESULTS

The levels of hemoglobin, hematocrit, total protein, and albumin were lower and the levels of lactate dehydrogenase and absolute reticulocytes higher during acute painful episodes than during the steady state. Surface-enhanced laser desorption/ionization time of flight mass spectrometry spectral analysis consistently showed a mass-to-charge peak at 11.7 kDa with elevated intensities during acute painful episodes, which correlated significantly with the serum amyloid A immunoassay. Serum amyloid A levels were significantly elevated during acute painful episodes, especially in four patients with marked end-organ complications of such episodes. A second, recurring peak, less abundant during acute painful episodes, was present at 28.1 kDa; this peak was correlated significantly with immunoassay measurements of apolipoprotein A1.

CONCLUSIONS

On the average, plasma serum amyloid A rises and apolipoprotein AI falls during acute painful episodes. The serum amyloid A/apolipoprotein AI ratio increased in 81% of the patients during acute painful episodes, potentially making it a useful objective marker of such episodes. We propose that these protein alterations, known to contribute to endothelial dysfunction in other settings, might do likewise acutely in acute painful episodes and present a new target for therapeutic intervention in sickle cell disease. (ClincalTrials.gov Identifier: NCT00081523).

Sodium nitrite promotes regional blood flow in patients with sickle cell disease: a phase I/II study

In addition to vaso-occlusion by sickled erythrocytes, the pathophysiology of sickle cell disease (SCD) is compounded by the diminished bioavailability of nitric oxide (NO), associated with vasoconstriction, endothelial activation and cell adhesion. We tested the ability of sodium nitrite, which can be converted to NO by deoxyhaemoglobin at acid pH and low oxygen tension, to improve blood flow in patients with SCD. In a phase I/II clinical trial, sodium nitroprusside, NG-monomethyl-L-arginine, and sodium nitrite were infused sequentially into the brachial artery in 14 patients at steady state. In a dose-dependent manner, sodium nitrite infusion rates of 0.4, 4 and 40 micromol/min into the brachial artery augmented mean venous plasma nitrite concentrations (P < 0.0001) and stimulated forearm blood flow up to 77 +/- 11% above baseline (P < 0.0001), measured by venous occlusion strain gauge plethysmography. This nitrite response was blunted significantly compared to controls without SCD, as previously seen with other NO donors. Sodium nitrite infusions were well tolerated without hypotension, clinically significant methaemoglobinaemia or other untoward events. The unique pharmacological properties of nitrite as a hypoxia-potentiated vasodilator and cytoprotective agent in the setting of ischaemia-reperfusion injury make this anion a plausible NO donor for future clinical trials in SCD.

Severity of pulmonary hypertension during vaso-occlusive pain crisis and exercise in patients with sickle cell disease

Pulmonary hypertension is associated with sudden death and is a risk factor for mortality in adult patients with sickle cell disease. The high mortality despite only mild-to-moderate increases in pulmonary vascular resistance remains an unresolved paradox. Accordingly, little is known about the cardiovascular effects of stressors, such as vaso-occlusive pain crisis (VOC) and exercise, which may acutely increase pulmonary pressures and impair right heart function. We therefore evaluated pulmonary artery pressures by echocardiogram in 25 patients with sickle cell disease in steady-state and during VOC, and by right heart catheterisation with exercise in a second cohort of 21 patients to determine whether pulmonary hypertension worsens during acute cardiopulmonary stress. TRV increased during VOC (P < 0.001), and the increased pulmonary pressures during VOC were associated with decreases in haemoglobin levels (P < 0.001), and increases in lactate dehydrogenase (P < 0.001) and plasma haemoglobin levels (P = 0.03). During exercise stress performed during cardiac catheterisation, mean pulmonary artery pressures (P < 0.001) and pulmonary vascular resistance increased (P < 0.001) in all subjects. These data suggest that acute elevations in pulmonary pressures during VOC or exercise may contribute to morbidity and mortality in patients with sickle cell disease.

Sickle cell disease and nitric oxide: a paradigm shift?

Traditionally the pathophysiology of sickle cell disease is thought to result from the polymerization of hemoglobin S in red cells, under hypoxic conditions, resulting in the occlusion of blood vessels. Adhesion of cells to the venular endothelium also appears to play a role. Recent studies have also suggested that in addition to the polymerization of hemoglobin S in the red blood cell, a deficiency of the endogenous vasodilator, nitric oxide may be involved. Hemoglobin released as a result of hemolysis rapidly consumes nitric oxide resulting in a whole program of events that inhibit blood flow. Therapies directed at decreasing the destruction of nitric oxide, increasing the production of nitric oxide, or amplifying the nitric oxide response may prove beneficial.

Significant responses to platinum-based chemotherapy in renal medullary carcinoma

Most patients with renal medullary carcinoma (RMC) have advanced disease at presentation and rarely respond to radiation or chemotherapy. We describe two adolescents with metastatic disease who had significant responses to cisplatin or carboplatin in combination with gemcitabine and paclitaxel.

Stimulation of proteolysis on calmodulin

The proteolysis of calmodulin by fungal protease (type XIX) was greatly enhanced in the presence of dGTP and MS2 RNA. Whereas, only moderate proteolytic activation on bacterial proteases (type XXVI) was observed in the presence of MS2 RNA. No appreciable proteolysis of calmodulin by bacterial protease (type IX) was observed. Proteolytic fragments of calmodulin cleaved by fungal protease exhibited unusual low mobility during SDS-polyacrylamide gel electrophoresis. Similar decreased electrophoretic mobility was also noted in the proteolytic fragments of other Ca2(+)-binding proteins including S-100A protein and parvalbumin.

Incidence of hemoglobins S and C in infants born in Miami to recent Haitian immigrants

The incidence of hemoglobins S and C was determined for infants born to mothers who had recently emigrated to Miami from Haiti. The rates for hemoglobin S trait was 8.0% and C trait 4.7%. These values were higher than those found for American Blacks studied during the same period. Rates for those homozygous for hemoglobin S and doubly heterozygous for hemoglobins S and C are also reported but due to the infrequency with which they occur, the rates are less reliable. These data demonstrate that these abnormal hemoglobins occur in a significant number of Haitians and implies the existence of a considerable number of individuals with sickle cell anemia and hemoglobin SC disease in that country. It is important that a definitive study be done in Haiti to more precisely quantitate the magnitude of the problem so that appropriate health care strategies can be developed.

Hemoglobin variations on a small Bahamian island

Hemoglobino characteristic were investigated in 492 blood specimens collected in a small island community (1,450 inhabitants) in the Bahamas. Using two different methods, abnormal variants were detected in 20.3% of the sample, including genotypes AS, AC, AF(A/HPFH), SC, and SF. Biodemographic evidence suggests that the origin and distribution of the hemoglobinpathies in this population have been influenced by historical migrations and genetic drift. The opportunity for drift has been particularly heightened by the "founder effect," the maintenance of small population size, a relatively endogamous mating structure, and restricted immigration. Health survey results reveal a wide discrepancy between the actual prevalence of abnormal hemoglobins and that indicated by informant reports.