Creation of a Severity Score Based on Simple Laboratory Criteria for Patients With Disseminated Histoplasmosis

Introduction/Objectives Histoplasmosis remains a relatively frequent opportunistic infection, associated with prolonged hospitalizations and use of high-cost medications, in addition to requiring substantial diagnostic investment (invasive tests and qualified professionals). Considering the difficulty in accessing parenteral therapy, it becomes necessary to rationalize the available resources without, however, posing risks to the patient. Results A retrospective analysis of 92 cases of disseminated histoplasmosis was performed, of which 62 evolved to hospital discharge and 30 to death during treatment of the fungal infection. Both groups had similar epidemiological characteristics in order to reduce bias. All cases had HIV coinfection. Based on clinical signs and accessible, non-invasive tests, the study proposes the creation of a severity score that can be replicated. The laboratory variables most statistically associated with the outcome “Death” were used: serum albumin level (≥3.5 g/dL = 0 points; between 3.4 and 2.7 g/dL = 1 point; between 2.6 and 2.1 g/dL = 2 points; and ≤2.0 g/dL = 3 points); hemoglobin (≥10 g/dL = 0 points; between 8.0 and 9.9 g/dL = 1 point; and ≤7.9 g/dL = 2 points); leukocytes, in thousands/mm³ (≥3.5 = 0 points; between 3.4 and 2.6 = 1 point; between 2.5 and 1.6 = 2 points; and ≤1.5 = 3 points); ferritin/Lactate dehydrogenase ratio (between 0 and 4.9 = 0 points; between 5.0 and 9.9 = 1 point; between 10.0 and 14.9 = 2 points; and ≥15.0 = 3 points); INR (between 1.0 and 1.2 = 0 points; between 1.3 and 1.5 = 1 point; between 1.6 and 1.9 = 2 points; and ≥2.0 = 3 points), in addition to the presence or absence of tachypnea and tachycardia (no = 0 points and yes = 1 point each). Patients in the “Discharge” group had scores between 3 and 9 points, whereas the “Death” group had scores ≥7 points. Thus, considering a positive predictive value for low risk of only 7% and a negative predictive value for high risk of 82.9%, we established cutoff points as follows: low risk = ≤4 points; moderate risk = 5–6 points; and high risk = ≥7 points. Conclusion The possibility of applying the proposed score to determine priority in requesting and releasing parenteral medication in the public health system helps in the rational use of the available resources.