Calcium crystal deposition diseases: lessons from histochemistry.

PURPOSE OF REVIEW: Recent progress in molecular biology and biochemistry has enabled researchers to identify possible key players in physiologic and pathologic calcification. However, important lessons from immunohistochemical studies have contributed greatly to our current understanding of the pathogenesis of calcium crystal deposition disease.

RECENT FINDINGS: Histologic findings led to the hypothesis of the important role of hypertrophic differentiation of articular chondrocytes in calcium crystal deposition. In addition, histologic studies have confirmed the importance of individual proteins that may have direct or indirect roles in calcium crystal formation.

SUMMARY: Future studies will determine whether in vitro data showing key roles for certain factors in mineralization and calcification in cartilage are relevant to crystal deposition disease in humans.