Acquired Gitelman's syndrome: an oxymoron?

Successful living kidney donation from a patient with a Gitelman's syndrome

Living kidney donation from Gitelman's syndrome (GS) patients remains very rare. Long-term renal prognosis of donor and recipient patients remains unknown. We report a 67-year-old man with GS, harbouring a mutation of the SLC12A3 gene, who donated his kidney for transplant. Five years post-transplantation, his clinical condition and biochemical parameters remained stable with close monitoring and follow-up. Patients with non-complicated GS can be considered eligible to donate their kidney for transplant.

Long-term Clinical Course after Living Kidney Donation by a Patient with Gitelman Syndrome Harboring a Compound Heterozygous Mutation of the SLC12A3 Gene

The eligibility for kidney donation and long-term post-donation renal prognosis of patients with Gitelman syndrome (GS) are unknown. We herein report a 44-year-old woman with GS who donated her kidney for transplant. A gene sequence analysis revealed compound heterozygous mutations of T180K and L858H in the SLC12A3 gene. Since transplantation, the renal function and serum potassium and magnesium levels of the donor and recipient have remained stable for seven years with careful monitoring and supplementation. Patients with asymptomatic GS who have no complications can be considered eligible to donate their kidney for transplant with proper monitoring after transplantation.

Gitelman Syndrome: A Rare Cause of Seizure Disorder and a Systematic Review

Gitelman syndrome is one of the few inherited causes of metabolic alkalosis due to salt losing tubulopathy. It is caused by tubular defects at the level of distal convoluted tubules, mimicking a thiazide-like tumor. It usually presents in late childhood or in teenage as nonspecific weakness, fatigability, polyuria, and polydipsia but very rarely with seizures. It is classically associated with hypokalemia, hypomagnesemia, hypocalciuria, hyperreninemia, and hyperaldosteronism. However, less frequently, it can present with normal magnesium levels. It is even rarer to find normomagnesemic patients of GS who develop seizures as the main complication since hypomagnesemia is considered the principal etiology of abnormal foci of seizure-related brain activity in GS cases. Interestingly, patients with GS are oftentimes diagnosed during pregnancy when the classic electrolyte pattern consistent with GS is noticed. Our case presents GS with normal serum magnesium in a patient, with seizures being the main clinical presentation. We also did a comprehensive literature review of 122 reported cases to show the prevalence of normal magnesium in GS cases and an overview of clinical and biochemical variability in GS. We suggest that further studies and in-depth analysis are required to understand the pathophysiology of seizures in GS patients with both normal and low magnesium levels.

Transplantation of a Gitelman Syndrome Kidney Ameliorates Hypertension: A Case Report

Gitelman syndrome is caused by inactivating mutations of the gene that encodes the renal sodium/chloride cotransporter (NCC; encoded by SLC12A3), resulting in hypokalemia, hypomagnesemia, hypocalciuria, and metabolic alkalosis. Renal salt wasting commonly provokes mild hypotension. The paucity of previous kidney transplants from donors with known tubulopathies suggests that such conditions may be considered contraindications to donation. A 76-year-old man received a live unrelated kidney transplant from a donor with known Gitelman syndrome secondary to a pathogenic mutation of SLC12A3. Immediate graft function preceded the emergence of the Gitelman syndrome biochemical phenotype and blood pressure subsequently improved. The recipient developed unexpected hyponatremia. Potential causes are discussed, including the possibility that it paralleled the physiologic changes seen in the high-volume state of thiazide-induced hyponatremia. Transplanted kidneys are subject to nephrotoxicity from the use of calcineurin inhibitors. Acquired Gitelman syndrome may confer a potential long-term advantage to the recipient through both improved blood pressure control and protection against the calcineurin inhibitor-induced side-effect profile caused by NCC overactivation. Both the donor and recipient remain well. In conclusion, Gitelman syndrome need not preclude kidney donation and transference of the phenotype may have benefits for the recipient.

Acquired Gitelman syndrome in a primary Sjögren syndrome patient with a SLC12A3 heterozygous mutation: A case report and literature review

Acquired Gitelman's syndrome (GS) associated with Sjögren syndrome (SS) is rare. A 50-year-old woman was admitted to our department because of nausea, acratia and sicca complex. Laboratory tests after admission showed renal failure, hypokalaemia, metabolic alkalosis, hypomagnesaemia and hypocalciuria, all of which met the diagnostic criteria for GS. Diagnostic evaluation identified primary SS as the cause of the acquired GS. Light microscopy of the renal tissue from the patient showed severe membranoproliferative glomerunephritis and tubulointerstitial nephritis. Immunohistochemical staining of the renal tissue showed the absence of sodium-chloride co-transporter (NCCT) in distal convoluted tubules. Genetic analysis of chromosomal DNA extracted from the patient's peripheral blood showed SLC12A3 gene heterozygous mutation. The reported case was comprehensively analyzed on the basis of the clinical features, and laboratory, pathological and genetic test findings. The patient has achieved a complete remission after meticulous care and appropriate treatment.

Probable C4d-negative accelerated acute antibody-mediated rejection due to non-HLA antibodies

We report a case of probable C4d-negative accelerated acute antibody-mediated rejection due to non-HLA antibodies. A 44 year-old male was admitted to our hospital for a kidney transplant. The donor, his wife, was an ABO minor mismatch (blood type O to A) and had Gitelman syndrome. Graft function was delayed; his serum creatinine level was 10.1 mg/dL at 3 days after transplantation. Open biopsy was performed immediately; no venous thrombosis was observed during surgery. Histology revealed moderate peritubular capillaritis and mild glomerulitis without C4d immunoreactivity. Flow cytometric crossmatching was positive, but no panel-reactive antibodies against HLA or donor-specific antibodies (DSAbs) to major histocompatibility complex class I-related chain A (MICA) were detected. Taken together, we diagnosed him with probable C4d-negative accelerated antibody-mediated rejection due to non-HLA, non-MICA antibodies, the patient was treated with steroid pulse therapy (methylprednisolone 500 mg/day for 3 days), plasma exchange, intravenous immunoglobulin (40 g/body), and rituximab (200 mg/body) were performed. Biopsy at 58 days after transplantation, at which time S-Cr levels were 1.56 mg/dL, found no evidence of rejection. This case, presented with a review of relevant literature, demonstrates that probable C4d-negative accelerated acute AMR can result from non-HLA antibodies.

Acquired Gitelman Syndrome in an Anti-SSA Antibody-positive Patient with a SLC12A3 Heterozygous Mutation

A 36-year-old woman developed hypokalemic metabolic alkalosis after anti SS-A antibody was found to be positive. Diuretic loading test results were compatible with Gitelman syndrome (GS). The patient had a heterozygous mutation in SLC12A3, which encodes for thiazide-sensitive NaCl cotransporter (NCCT). While the mutation may be responsible for a latent hypofunction of NCCTs, the underlying anti-SSA antibody-associated autoimmunity induced the manifestation of its hypofunction. To the best of our knowledge, this is the first report to demonstrate that anti SS-A antibody-associated autoimmunity may induce GS in a patient with a SLC12A3 heterozygous mutation.