Khan Edmat Akhtar, Cheddani Lynda, Saint-Jacques Camille, Vargas-Poussou Rosa, Frochot Vincent, Chieze Remi, Letavernier Emmanuel, Avellino Virginie, Lionnet Francois, Haymann Jean-Philippe
Service de Néphrologie, Université de Lorraine, CHRU-Nancy, 54500 Vandœuvre-lès-Nancy, France.
Unité HTA, Prévention et Thérapeutique Cardiovasculaires, Assistance Publique-Hôpitaux de Paris, Hôpital Hôtel Dieu, 75004 Paris, France.
J Clin Med. 2021 Nov 5;10(21):5179. doi: 10.3390/jcm10215179.
Primary hyperparathyroidism (pHPT) has been reported to have a higher prevalence in sickle cell disease (SCD) patients, including a high rate of recurrence following surgery. However, most patients are asymptomatic at the time of diagnosis, with surprisingly infrequent hypercalciuria, raising the issue of renal calcium handling in SCD patients. We conducted a retrospective study including (1) 64 hypercalcemic pHPT non-SCD patients; (2) 177 SCD patients, divided into two groups of 12 hypercalcemic pHPT and 165 non-pHPT; (3) eight patients with a diagnosis of familial hypocalciuric hypercalcemia (FHH). Demographic and biological parameters at the time of diagnosis were collected and compared between the different groups. Determinants of fasting fractional excretion of calcium (FeCa) were also analyzed in non-pHPT SCD patients. Compared to non-SCD pHPT patients, our data show a similar ionized calcium and PTH concentration, with a lower plasmatic calcitriol concentration and a lower daily urinary calcium excretion in pHPT SCD patients ( < 0.0001 in both cases). Fasting FeCa is also surprisingly low in pHPT SCD patients, and thus inadequate to be considered hypercalcemia, recalling the FHH phenotype. FeCa is also low in the non-pHPT SCD control group, and negatively associated with PTH and hemolytic biomarkers such as LDH and low hemoglobin. Our data suggest that the pHPT biochemical phenotype in SCD patients resembles the FHH phenotype, and the fasting FeCa association with chronic hemolysis biomarkers strengthens the view of a potential pharmacological link between hemolytic by-products and calcium reabsorption, potentially through a decreased calcium-sensing receptor (CaSR) activity.
据报道，原发性甲状旁腺功能亢进症（pHPT）在镰状细胞病（SCD）患者中的患病率较高，包括术后复发率也很高。然而，大多数患者在诊断时无症状，高钙尿症的发生率惊人地低，这就引发了SCD患者肾钙处理的问题。我们进行了一项回顾性研究，包括：（1）64例高钙血症pHPT非SCD患者；（2）177例SCD患者，分为12例高钙血症pHPT患者和165例非pHPT患者两组；（3）8例诊断为家族性低钙尿性高钙血症（FHH）的患者。收集了不同组诊断时的人口统计学和生物学参数并进行比较。还对非pHPT SCD患者空腹钙排泄分数（FeCa）的决定因素进行了分析。与非SCD pHPT患者相比，我们的数据显示，pHPT SCD患者的离子钙和甲状旁腺激素（PTH）浓度相似，但血浆骨化三醇浓度较低，每日尿钙排泄量也较低（两者均<0.0001）。pHPT SCD患者的空腹FeCa也出奇地低，因此不足以被视为高钙血症，这让人想起FHH的表型。非pHPT SCD对照组的FeCa也较低，且与PTH以及乳酸脱氢酶（LDH）和低血红蛋白等溶血生物标志物呈负相关。我们的数据表明，SCD患者的pHPT生化表型类似于FHH表型，空腹FeCa与慢性溶血生物标志物的关联强化了溶血副产物与钙重吸收之间可能存在药理学联系的观点，这可能是通过降低钙敏感受体（CaSR）活性实现的。
