title: [Two patients with renal medullary hyperechogenicity].
abstract: METHODS
  We report two patients with medullary nephrocalcinosis and nephrolithiasis. The first patients had unspecific symptoms of a systemic inflammatory disease, the second patient was asymptomatic.
  
  
  METHODS
  Both patients had normocalcemia and normal parathyroid hormone levels, very high 1,25(OH)(2)-vitamin D and normal to low 25-OH-vitamin D levels. On renal ultrasound, both patients displayed nephrocalcinosis and nephrolithiasis.
  
  
  METHODS
  Both patients showed dysregulation of the 1α-hydroxylase activity. The first patient suffered from a systemic inflammatory disease with consecutive activation of macrophages with extrarenal α-hydroxylase activity. The second patient had a "loss of function" mutation of the calcium sensing receptor with - for the situation - inadequatly high parathyroid hormone levels and consequently a renal dysregulation of the 1α-hydroxylase.
  
  
  METHODS
  After immunosuppressive treatment with prednisolone and hydroxychloroquin there was complete remission of the systemic inflammatory disease in the first patient. In consequence the 1,25-(OH)(2)-vitamin D levels regressed and renal function stabilized. The second patient was completely asymptomatic with normal renal function, so far we did not initiate any treatment.
  
  
  CONCLUSIONS
  Nephrocalcinosis and nephrolithiasis can result from hypercalciuria due to dysregulated hydroxylation of vitamin D. For both renal and extrarenal sources causal treatment is available.
authors.affiliation: Medizinische Universitätsklinik Tübingen, Abteilung für Endokrinologie, Diabetologie, Nephrologie, Angiologie und Klinische Chemie. nora.celebi@med.unituebingen.de
authors.forename: Nora
authors.initials: N
authors.lastname: Celebi
authors.forename: Georg
authors.initials: G
authors.lastname: Georges
authors.forename: Fausto
authors.initials: F
authors.lastname: Machicao
authors.forename: Ferruh
authors.initials: F
authors.lastname: Artunc
authors.forename: Ingo
authors.initials: I
authors.lastname: Rettig
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000097:blood; D002118:Calcium / Q000097:blood; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006886:Hydroxychloroquine / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007677:Kidney Function Tests; D007679:Kidney Medulla / Q000000981:diagnostic imaging*; D009397:Nephrocalcinosis / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics; D053040:Nephrolithiasis / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics; D010281:Parathyroid Hormone / Q000097:blood; D011239:Prednisolone / Q000627:therapeutic use; D044169:Receptors, Calcium-Sensing / Q000235:genetics; D014463:Ultrasonography; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D007166:Immunosuppressive Agents; D010281:Parathyroid Hormone; D044169:Receptors, Calcium-Sensing; D014807:Vitamin D; D006886:Hydroxychloroquine; C097949:1,25-dihydroxyvitamin D; D011239:Prednisolone; C104450:25-hydroxyvitamin D; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D002118:Calcium