Sickling cells, cyclic nucleotides, and protein kinases: the pathophysiology of urogenital disorders in sickle cell anemia

Endocrinopathies in Hemoglobinopathies: What Is the Role of Iron?

Hemoglobinopathies, including β-thalassemia and sickle cell disease (SCD), are common genetic blood disorders. Endocrine disorders are frequent manifestations of organ damage observed mainly in patients with β-thalassemia and rarely in SCD. Iron overload, oxidative stress-induced cellular damage, chronic anemia, and HCV infection contribute to the development of endocrinopathies in β-thalassemia. The above factors, combined with vaso-occlusive events and microcirculation defects, are crucial for endocrine dysfunction in SCD patients. These endocrinopathies include diabetes mellitus, hypothyroidism, parathyroid dysfunction, gonadal and growth failure, osteoporosis, and adrenal insufficiency, affecting the quality of life of these patients. Thus, we aim to provide current knowledge and data about the epidemiology, pathogenesis, diagnosis, and management of endocrine disorders in β-thalassemia and SCD. We conducted a comprehensive review of the literature and examined the available data, mostly using the PubMed and Medline search engines for original articles. In the era of precision medicine, more studies investigating the potential role of genetic modifiers in the development of endocrinopathies in hemoglobinopathies are essential.

Enuresis and overactive bladder in sickle cell patients: a narrative review of the literature

OBJECTIVE

The aim of this review is to clarify the prevalence, pathophysiology and clinical presentation of enuresis and overactive bladder in sickle cell patients.

MATERIALS AND METHODS

This narrative review of the literature was conducted in March 2022 by running a search in PubMed, Embase, Scopus and Cochrane databases without publication date limitation, using the following keywords: enuresis or nocturia or overactive bladder or urinary incontinence or bedwetting and sickle cell.

RESULTS

Eight cross-sectional studies were included, six of which had a non-sickle cell control population. The prevalence of enuresis in children and adolescents with sickle cell disease ranged from 20.3 to 49.4%. It decreased with age to 2.9% in adult sickle cell patients. Enuresis in sickle cell patients has been attributed to several causes, including lack of urine concentration with nocturnal polyuria, reduced bladder capacity, nocturnal bladder hyperactivity, sleep and/or respiratory disorders are likely causes of enuresis in sickle cell patients. The prevalence of overactive bladder is three times higher in sickle cell patients than in control groups. The latter is also observed three times more frequently in men who have had prior episodes of priapism.

CONCLUSION

Enuresis and overactive bladder are common in sickle cell patients. Several mechanisms have been described to try to explain enuresis in sickle cell patients but overactive bladder seems to play a major role. Studies evaluating the efficacy of certain experimentally validated treatments must be carried out to improve the management of these complications which affect the quality of life of sickle cell patients.

Platelet volume parameters as a tool in the evaluation of acute ischemic priapism in patients with sickle cell anemia

OBJECTIVE

This study aimed to evaluate the predictive value of platelet volume indices (PVIs), such as mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT), as prognostic parameters of detumescence in acute ischemic priapism (IP) patients with sickle cell anemia (SCA) in steady-state who received intracavernosal injections of phenylephrine with aspiration and saline irrigation.

METHODS

Fifty-six SCA patients with acute IP and 54 healthy male control subjects were included in the research. Priapism was diagnosed by penile Doppler ultrasound and corporal blood gas tests before intervention. Measurements of PVIs (MPV, PDW, and PCT) and TLC were ordered for all participants. Additionally, the duration of priapism was recorded. The area under the curves was calculated by receiver operating characteristic (ROC) regression analysis.

RESULTS

The detumescence rate was 71.4% after the intervention. Compared to the control group, priapic SCA patients showed significantly higher PLT (p = 0.011), MPV (p = 0.002), PDW (p = 0.032), PCT values (p = 0.022), and TLC (p = 0.027). Higher MPV, PDW, and PCT values were observed in unsuccessful detumescence patients compared to the resolution group (p < 0.05). Statistically significant cutoff values for persistent priapism were measured by ROC as PLT: ⩾ 254x103/μL; MPV: ⩾ 13.2 fL; PDW: ⩾ 15.6 fL; PCT: ⩾ 24%; and TLC ≥ 8.5x103/L. Priapism duration of ≤ 17.9 hours was significantly related to detumescence rate (p = 0.000). Multivariable logistic regression analysis showed that priapism duration and higher MPV are prognostic parameters for detumescence in SCA.

CONCLUSIONS

The higher MPV and duration of priapism can be used as parameters for evaluating detumescence outcomes in steady-state SCA with acute IP.

High platelet distribution width can independently predict testicular survival in testicular torsion among patients with steady-state sickle cell anemia

Objective

This study aimed to evaluate the predictive value of platelet volume indices (PVI), such as mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT), as prognostic indicators of testicular viability in torsion patients with steady-state sickle cell anemia (SCA) who underwent surgical exploration.

Methods

Forty-eight patients with SCA with testicular torsion and 46 male control subjects were enrolled in the study. All patients underwent scrotal color Doppler ultrasonography before surgery, and PVI (MPV, PDW, and PCT) values were measured in all participants. Symptom duration and testicular volume were also recorded.

Results

The testicular salvage rate in patients with SCA was 73% after surgery. Analyses showed that MPV, PDW, and PCT values were significantly higher in torsed SCA as compared with controls (p<0.05). Orchiectomy in patients with SCA showed significantly higher MPV, PDW, and PCT values than the orchiopexy group (p<0.05). The MPV values of orchiectomy patients showed a higher significant cut-off of ≥11.5 fL, which is higher than in torsed patients without SCA, as an indicator of testis survival. PDW also demonstrated a higher significant cut-off of ≥12.7 fL for detorsion outcomes in patients with SCA. Symptom duration of less than 7 hours was also significantly correlated with orchiopexy (p≤0.001). Univariate analysis showed that higher MPV, increased PDW, and symptom duration were indicative of the outcome of testicular detorsion in SCA. Multivariable analysis showed that increased PDW and symptom duration are prognostic parameters for testicular viability in SCA.

Conclusion

Increased PDW and symptom duration can be used as parameters for predicting testicular detorsion outcomes in patients with steady-state SCA.

Testosterone Deficiency in Sickle Cell Disease: Recognition and Remediation

Hypogonadism is common in men with sickle cell disease (SCD) with prevalence rates as high as 25%. Testicular failure (primary hypogonadism) is established as the principal cause for this hormonal abnormality, although secondary hypogonadism and compensated hypogonadism have also been observed. The underlying mechanism for primary hypogonadism was elucidated in a mouse model of SCD, and involves increased NADPH oxidase-derived oxidative stress in the testis, which reduces protein expression of a steroidogenic acute regulatory protein and cholesterol transport to the mitochondria in Leydig cells. In all men including those with SCD, hypogonadism affects physical growth and development, cognition and mental health, sexual function, as well as fertility. However, it is not understood whether declines in physical, psychological, and social domains of health in SCD patients are related to low testosterone, or are consequences of other abnormalities of SCD. Priapism is one of only a few complications of SCD that has been studied in the context of hypogonadism. In this pathologic condition of prolonged penile erection in the absence of sexual excitement or stimulation, hypogonadism exacerbates already impaired endothelial nitric oxide synthase/cGMP/phosphodiesterase-5 molecular signaling in the penis. While exogenous testosterone alleviates priapism, it disadvantageously decreases intratesticular testosterone production. In contrast to treatment with exogenous testosterone, a novel approach is to target the mechanisms of testosterone deficiency in the SCD testis to drive endogenous testosterone production, which potentially decreases further oxidative stress and damage in the testis, and preserves sperm quality. Stimulation of translocator protein within the transduceosome of the testis of SCD mice reverses both hypogonadism and priapism, without affecting intratesticular testosterone production and consequently fertility. Ongoing research is needed to define and develop therapies that restore endogenous testosterone production in a physiologic, mechanism-specific fashion without affecting fertility in SCD men.

Prevalence of enuresis and its impact in quality of life of patients with sickle cell disease

INTRODUCTION

Evidence indicates an increase in the prevalence of enuresis in individuals with sickle cell disease. The present study aims to evaluate the prevalence and impact of enuresis on quality of life in individuals with sickle cell disease.

MATERIALS AND METHODS

This cross-sectional study evaluated individuals with sickle cell disease followed at a reference clinic, using a questionnaire designed to evaluate the age of complete toilet training, the presence of enuresis and lower urinary tract, and the impact on quality of life of these individuals.

RESULTS

Fifty children presenting SCD (52% females, mean age ten years) were included in the study. Of those, 34% (17/50) presented as HbSC, 56% with HbSS (28/50), 2% Sα-thalassemia (1/5) and 8% the type of SCD was not determined. The prevalence of enuresis was 42% (21/50), affecting 75% of subjects at fi ve years and about 15% of adolescents at 15 years of age. Enuresis was classifi ed as monosymptomatic in 33.3% (7/21) and nonmonosymptomatic in 66.6% (14/21) of the cases, being primary in all subjects. Nocturia was identifi ed in 24% (12/50), urgency in 20% (10/50) and daytime incontinence 10% (5/50) of the individuals. Enuresis had a signifi cant impact on the quality of life of 67% of the individuals.

CONCLUSION

Enuresis was highly prevalent among children with SCD, and continues to be prevalent throughout early adulthood, being more common in males. Primary nonmonosymptomatic enuresis was the most common type, and 2/3 of the study population had a low quality of life.

Low nitric oxide level is implicated in sickle cell disease and its complications in Ghana

BACKGROUND

Nitric oxide (NO) plays a fundamental role in maintaining normal vasomotor tone. Recent clinical and experimental data suggest that NO may play a role in the pathogenesis and therapy of sickle cell disease (SCD). The aim of this study was to determine NO metabolites (NOx) in SCD patients at steady state and in vaso-occlusive crisis (VOC), as well as those with hemolytic clinical sub-phenotype that includes leg ulcers and priapism.

METHODOLOGY

This was a case-control cross-sectional study conducted on a total of 694 subjects including 148 comparison group HbAA, 208 HbSS SCD patients in steady state, 82 HbSC SCD patients in steady state, 156 HbSS SCD patients in VOC, 34 HbSC SCD patients in VOC, 34 HbSS SCD patients in post VOC, 21 HbSS SCD patients with leg ulcer and 11 HbSS SCD patients with priapism, with age ranging from 15 to 65 years. Laboratory diagnosis of SCD was done at the Sickle Cell Clinic of the Korle-Bu Teaching Hospital. Plasma nitric oxide metabolites were measured using Griess reagent system by ELISA method.

RESULTS

Mean NOx of 59.66±0.75 µMol/L in the comparison group was significantly different from those in steady state (P=0.02). During VOC, there was a significant reduction in mean NOx levels to 6.08±0.81 µMol/L (P<0.001). Mean NOx levels were however, significantly higher (50.97±1.68 µMol/L) (P<0.001) in the immediate postcrisis period. The mean NOx levels in the leg ulcer (21.70±1.18 µMol/L) (P<0.001) and priapism (28.97±1.27 µMol/L) (P<0.001) patients were significantly low as compared to the SCD patients in the steady state and comparison group.

CONCLUSION

This study presents the first report on plasma NOx levels in SCD complication in Ghanaian SCD patients and confirms reduced plasma NOx levels in SCD patients in general.

Testicular infarction in a patient with sickle cell anemia: A case report

Sickle cell anemia is one of the common inherited hemoglobinopathy disorders. It affects patient quality of life through different types of complications. Brain, lung, kidney, spleen, and bone marrow commonly affected; however, testicular infarction is rarely happened. This is a 29-year-old Saudi male who is known for sickle cell disease (SCD). He presented with left scrotal pain and swelling for 1 week which did not respond to antibiotic. Scrotal ultrasound showed swollen heterogeneous hypoechoic left testicle with no blood flow, suggesting testicular infarction. Despite medical treatment, the patient went for orchiectomy. Pathology revealed extensive testicular infarction. Up to our knowledge, this is the first case report of testicular infarction in SCD in Arab countries, and the sixth case reported worldwide. Early diagnosis and doing unnecessary surgical intervention still unavoidable as there is lack of information. We think writing the first case of testicular infarction in sickle cell patients with Arab haplotype is worthful and it will add to the literature.

Urinary Bladder Dysfunction in Transgenic Sickle Cell Disease Mice

Background

Urological complications associated with sickle cell disease (SCD), include nocturia, enuresis, urinary infections and urinary incontinence. However, scientific evidence to ascertain the underlying cause of the lower urinary tract symptoms in SCD is lacking.

Objective

Thus, the aim of this study was to evaluate urinary function, in vivo and ex vivo, in the Berkeley SCD murine model (SS).

Methods

Urine output was measured in metabolic cage for both wild type and SS mice (25-30 g). Bladder strips and urethra rings were dissected free and mounted in organ baths. In isolated detrusor smooth muscle (DSM), relaxant response to mirabegron and isoproterenol (1nM-10μM) and contractile response to (carbachol (CCh; 1 nM-100μM), KCl (1 mM-300mM), CaCl₂ (1μM-100mM), α,β-methylene ATP (1, 3 and 10 μM) and electrical field stimulation (EFS; 1-32 Hz) were measured. Phenylephrine (Phe; 10nM-100μM) was used to evaluate the contraction mechanism in the urethra rings. Cystometry and histomorphometry were also performed in the urinary bladder.

Results

SS mice present a reduced urine output and incapacity to produce typical bladder contractions and bladder emptying (ex vivo), compared to control animals. In DSM, relaxation in response to a selective β3-adrenergic agonist (mirabegron) and to a non-selective β-adrenergic (isoproterenol) agonist were lower in SS mice. Additionally, carbachol, α, β-methylene ATP, KCl, extracellular Ca²⁺ and electrical-field stimulation promoted smaller bladder contractions in SS group. Urethra contraction induced by phenylephrine was markedly reduced in SS mice. Histological analyses of SS mice bladder revealed severe structural abnormalities, such as reductions in detrusor thickness and bladder volume, and cell infiltration.

Conclusions

Taken together, our data demonstrate, for the first time, that SS mice display features of urinary bladder dysfunction, leading to impairment in urinary continence, which may have an important role in the pathogenesis of the enuresis and infections observed the SCD patients.