Thrombocytopenia Warrants Clinical Attention in Hospitalized Patients with Sarcoidosis

Background: Long-term survival in sarcoidosis patients can be predicted by several clinical and laboratory parameters. Hypercalcemia serves as a predominant, negative prognostic factor. In the current study, we aimed to identify other patient characteristics influencing outcomes over a 10-year period. Methods: This was a retrospective analysis of hospitalized sarcoidosis patients in a large, tertiary medical center. Results: During a 10-year period between 2014 and 2024, data from 89 sarcoidosis patients was collected using MDClone data-mining software. Overall, 13 patients suffered from hypercalcemia (median, corrected for blood albumin: 10.3 mg/dL [9.9–10.5] vs. 9.5 [9.2–9.8], p < 0.001). Patients with hypercalcemia had higher rates of renal failure (30.8% vs. 3.9%, p = 0.008), lower platelet counts (median 153 K/mcl [113–170] vs. 230 [190.7–263.5], p < 0.001), lower hemoglobin concentrations (median 10.2 g/dL [10.0–11.3] vs. 12.5 [10.8–13.6], p < 0.01), higher urea blood levels (median 88 mg/dL [46–130] vs. 38.5 [30–47.2], p < 0.001), higher creatinine levels (median 1.48 mg/dL [1.31–1.6] vs. 0.9 [0.76–1.05], p < 0.001), and lower albumin (mean 3.07 g/dL ± 0.47 vs. 3.57 ± 0.56, p = 0.003). Hypercalcemia was associated with lower, post-discharge survival rates (median 4.8 years [2.6–7.3] vs. 7.9 [3.3–12.1], p = 0.045) and higher rates of 3-year, post-discharge mortality (30.8% vs. 7.9%, p = 0.036). Thrombocytopenia was present in six patients (6.7%); four (66.7%) died within three years, compared with six of 83 patients without thrombocytopenia (7.2%; p = 0.001). In univariate analysis, hypercalcemia and thrombocytopenia were both associated with a higher risk of mortality within 3 years (HR = 4.11, 95% CI 1.16–14.57, p = 0.029 and HR = 13.92, 95% CI 3.88–49.93, p < 0.001, respectively). However, in a multivariate analysis, only patient age and thrombocytopenia continued to be associated with a statistically significant higher risk of death (HR = 7.04, 95% CI 1.46–33.99, p = 0.015). Five of the six patients with thrombocytopenia (83.3%) were subsequently diagnosed with hematologic malignancy, months to years after thrombocytopenia was identified. Conclusions: Thrombocytopenia was associated with higher three-year mortality and may represent a clinical warning sign for occult or subsequently diagnosed hematologic malignancy in patients with sarcoidosis.