Short-cut diagnostic tool in cystinosis: Bone marrow aspiration.

BACKGROUND: Cystinosis is a rare metabolic genetic disorder caused by a mutation in cystinosin lysosomal cystine transporter (CTNS). The diagnosis of nephropathic cystinosis (NC) is made by observing corneal cystine crystals and/or measuring the cystine content of leukocytes. CTNS mutation analysis confirms the diagnosis of cystinosis, but leukocyte cystine measurement and CTNS analysis have not been widely available, and cystine crystals in the cornea may not be apparent in the first months of life. Cystine crystal deposition can be seen in the bone marrow earlier than corneal deposition, in patients with NC. METHODS: Ten patients with cystinosis diagnosis were enrolled in the study. Medical records were reviewed retrospectively to collect demographic and clinical data such as age at diagnosis, disease presentation, parental consanguinity, family history, corneal cystine deposition, leukocyte cystine level, bone marrow cystine deposition, presence of renal failure, follow-up time and prognosis. RESULTS: Cystine crystals were seen in all of the patients' fresh bone marrow aspiration samples. Eight patients had corneal cystine deposition. Leukocyte cystine measurement could have been performed in four patients who had come from another center. Complications such as pulmonary hypertension and idiopathic intracranial hypertension (IIH) were observed in two patients. CONCLUSIONS: Bone marrow aspiration might be an easy and short-cut diagnostic tool for NC especially when it is not possible to measure fibroblast cystine content. Additionally some rare complications such as pulmonary hypertension and IIH can be encountered during the course of NC.

Hemolytic uremic syndrome and IgA nephropathy in a child: Coincidence or not?

Sürmeli-Döven S, Delibas A, Gürses I, Kayacan UR, Coskun-Yilmaz B, Esen K, Korkmaz E, Özaltin F. Hemolytic uremic syndrome and IgA nephropathy in a child: Coincidence or not? Turk J Pediatr 2018; 60: 81-85. A previously healthy 18-month old boy, presenting with diarrhea, anemia, thrombocytopenia and acute renal failure was admitted to our hospital. Hemolytic uremic syndrome (HUS) was diagnosed with his clinical and laboratory findings. His stool was negative for Shiga toxin producing E. coli (STEC). During follow-up he developed respiratory distress, hypertrophic cardiomyopathy and seizure. His genetic tests for atypical HUS (aHUS) were negative. His clinical and histological findings indicated hemolytic uremic syndrome and immunglobulin A nephropathy (IgAN). The patient responded to steroid treatment and plasma exchange therapy with peritoneal dialysis. We discuss the probable connection between HUS and IgAN.