Infectious Complications in Acute Leukemia, Experience in a Public Institution in Mexico

Infectious complications are a major cause of morbidity and mortality in hematologic patients with acute leukemia. In this paper we address the mayor infectious complications, at the Leukemia Clinic (LC) in the Instituto Nacional de Cancerologia (INCan)

Material and Methods.

This is a retrospective, observational study, carried on at INCan. We included all patients that attended the LC and died of an infectious complication between January 2012 and December 2014, regardless of status (new case/relapsed) at diagnosis, we included patients with Acute Lymphoblastic Leukemia (ALL), Acute Myeloid Leukemia (AML), Acute Biphenotypic Leukemia (ABL) and Acute Promyelocytic Leukemia (APML).

The main objective of the study was to determine the most frequent causes of infectious complications in the treatment of acute leukemias.

Results.

We included 240 patients that were admitted to the LC between the study dates. 12 patients were excluded since they were later diagnosed with another hematologic malignancy rather than leukemia. 228 patients were analyzed. 132 males, 96 females, 36 years was the median age (14-85 years). 126 patients were new cases and 102 patients were treated for relapse. AML 69 patients, ALL 140 patients, ABL 9 patients, and APML 10 patients.

We revised the data of all the deaths that occurred in the period of time. 100 cases were included in the study, of those, 30 that were not infectious related and were excluded.

Of the 40 patients included, 41 were males and 29 females, with a mean age of 36.8 years (16-72). 44 ALL patients, 18 AML patients, 7 ABL patients and 1 APML patient. 32 patients were new cases and 38 were relapses. The media number of relapses was 1 (1-3).

Septic Shock was stated as the cause of death on all electronic files, with Pneumonia as the most common cause of infection origin with 47 patients. As for determining the causal agent of the infection, we used the last positive culture 5 days prior to the death, we found a causal agent in only 47 patients; the most frequent agents involved were: Escherichia coli BLEE with 13 patients, Enterococus faecium with 6 patients, we also report 1 H1N1 and 1 H3N2 influenza infections.

14 patients did not received intensive chemotherapy prior to death, 11 were on supportive care, and 3 of them did not consent treatment.

HyperCVAD was the most frequent regimen administered prior to death, with 13 patients, 7+3 followed with 11 patients. POMP in the setting of palliative regimen was also prevalent with 12 patients. 52% of the patients were in nadir of chemotherapy, with a mean of days of 19 (3-64). All patients that received intensive chemotherapy received GSFC and meropenem/vancomycin regimen once septic shock was diagnosed according to the data in the electronic file.

All patients received treatment in the beginning, of the 70 patients only 19 were treated in the intensive care unit (ICU).

Conclusions.

We addressed the most frequent causes of infectious complications at the Acute Leukemia Clinic, as we thought, E. coli BLEE was the most frequent agent involved, perhaps diverting from reports in the literature, we have a low prevalence of gram positive cocci. Pneumonia is the most frequent site of infection, all our patients are admitted to for chemotherapy, hence all the pneumonia cases are hospital acquired. POMP is a prevalent regimen reported, since we use this regimen for palliative care we could relate mortality to relapse/refractory disease more than to toxicity itself. No maintenance regimens were reported in the results. Our study has certain limitations, no mycotic infections could be reported as the electronic file lacks reliable information.