Gitelman syndrome associated with chondrocalcinosis and severe neuropathy: a novel heterozygous mutation in SLC12A3 gene.

Gitelman syndrome (GS) is an inherited salt-wasting tubulopathy characterized by hypocalciuria, hypokalemia, hypomagnesemia and metabolic alkalosis, due to inactivating mutations in the SLC12A3 gene. Symptoms may be systemic, neurological, cardiovascular, ophthalmological or musculoskeletal. We describe a 70 year-old patient affected by recurrent arthralgias, hypoesthesia and hyposthenia in all 4 limbs and severe hypokalemia, complicated by atrial flutter. Moreover, our patient reported eating large amounts of licorice, and was treated with medium-high dosages of furosemide, thus making diagnosis very challenging. Genetic analysis demonstrated a novel heterozygous mutation in the SLC12A3 gene; therefore, we diagnosed GS and started potassium and magnesium replacement. GS combined with chondrocalcinosis and neurological involvement is quite common, but this is the first case of an EMG-proven severe neuropathy associated with GS. Herein, we underline the close correlation between hypomagnesemia, chondrocalcinosis and neurological involvement. Moreover, we report a new heterozygous mutation in exon 23 (2738G>A), supporting evidence of a large genetic heterogeneity in this late-onset congenital tubulopathy.

Immunoglobulins in systemic sclerosis management. A large multicenter experience.

OBJECTIVE: To analyze the effectiveness and safety of intravenous immunoglobulin (IVIG) given in routine care to patients with systemic sclerosis (SSc). METHODS: A retrospective multicenter observational study was conducted in SSc patients treated with IVIG. We collected data on epidemiological parameters and clinical outcomes. Firstly, we assessed changes in organ manifestations during IVIG treatment. Secondly, we analyzed the frequency of adverse effects. The following parameters were collected from baseline to the last follow-up: the patient's weight, modified Rodnan Skin Score (mRSS), modified manual muscle strength scale (MRC), laboratory test(creatine kinase(CK), hemoglobin and protein levels), The University of California Los Angeles Scleroderma Clinical Trials Consortium gastrointestinal tract 2.0 (UCLA GIT 2.0) questionnaire, pulmonary function tests, and echocardiography. RESULTS: Data were collected on 78 patients (82% females; 59% with diffuse SSc). Inflammatory idiopathic myopathy was the most frequent concomitant overlap disease (41%). The time since Raynaud's phenomenon and SSc onset were 8.8 ± 18 and 6.2 ± 6.7 years respectively. The most frequent IVIG indication was myositis (38/78), followed by gastrointestinal (27/78) and cutaneous (17/78) involvement. The median number of cycles given were 5. 54, 53 and 9 patients have been treated previously with glucocorticoids, synthetic disease-modifying antirheumatic drugs and biologic therapies respectively. After IVIG use we found significant improvements in muscular involvement (MRC ≥ 3/5 92% IVIG, p = 0.001 and CK levels from 1149 ± 2026 UI to 217 ± 224 UI, p = 0.02), mRSS (15 ± 12.4 to 13 ± 12.5, p = 0.015) and improvement in total score of UCLA GIT 2.0 (p = 0.05). None Anti-RNA polymerase III patients showed an adequate response in gastrointestinal involvement (0/7) in comparison with other antibodies (0 vs. 25, p = 0,039). Cardiorespiratory involvement remained stable. A total of 12 adverse events were reported with only one withdrawn due to serious adverse effect. CONCLUSIONS: this study suggest that IVIG may improve myositis, gastrointestinal and skin involvement in SSc patients treated in routine care and seems to have a good safety profile.