IMAGES IN CLINICAL MEDICINE. Cystine Crystals in Bone Marrow

Dental implant placement in a patient with cystinosis. A case report

Introduction: Cystinosis is a rare genetic disease due to a defective transport of cystine out of the lysosomes, caused by a mutation of the gene encoding for the lysosomal carrier protein, the cystinosin. Cystine accumulation results in the formation of intracellular cystine cristals, that causes tissular and multi-organic lesions (kidney, eyes, endocrine glands). Observation: We report a rare case of a patient affected by infantile nephropathic cystinosis, who consulted for an implant placement in a single-tooth gap. Discussion: Accumulation of cystine leads to tissue damage, primarily in the kidney, the liver and the cornea, but other organs, such as the mouth, teeth and jaws may be also involved. The article aimed to present oral manifestations associated with this storage disease and to discuss how oral surgeon can evaluate and manage these patients despite the lack of a standardized protocol.

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.

Nephropathic cystinosis: an update

PURPOSE OF REVIEW

Over the past few decades, cystinosis, a rare lysosomal storage disorder, has evolved into a treatable metabolic disease. The increasing understanding of its pathophysiology has made cystinosis a prototype disease, delivering new insights into several fundamental biochemical and cellular processes.

RECENT FINDINGS

In this review, we aim to provide an overview of the latest advances in the pathogenetic, clinical, and therapeutic aspects of cystinosis.

SUMMARY

The development of alternative therapeutic monitoring strategies and new systemic and ocular cysteamine formulations might improve outcome of cystinosis patients in the near future. With the dawn of stem cell based therapy and new emerging gene-editing technologies, novel tools have become available in the search for a cure for cystinosis.

Elasticity in Macrophage-Synthesized Biocrystals

Supramolecular crystalline assembly constitutes a rational approach to bioengineer intracellular structures. Here, biocrystals of clofazimine (CFZ) that form in vivo within macrophages were measured to have marked curvature. Isolated crystals, however, showed reduced curvature suggesting that intracellular forces bend these drug crystals. Consistent with the ability of biocrystals to elastically deform, the inherent crystal structure of the principal molecular component of the biocrystals-the hydrochloride salt of CFZ (CFZ-HCl)-has a corrugated packing along the (001) face and weak dispersive bonding in multiple directions. These characteristics were previously found to be linked to the elasticity of other organic crystals. Internal stress in bent CFZ-HCl led to photoelastic effects on the azimuthal orientation of polarized light transmittance. We propose that elastic, intracellular crystals can serve as templates to construct functional microdevices with different applications.