Preprocedural prophylaxis with blood products in patients with cirrhosis: Results from a survey of the Italian Association for the Study of the Liver (AISF).

INTRODUCTION: The concept of rebalanced hemostasis in cirrhosis challenges the policy of transfusing plasma or platelets before invasive procedures in patients with prolonged PT or severe thrombocytopenia. Recent guidelines recommend against plasma transfusion and suggest avoiding/minimizing platelet transfusions. AIM: We assessed how hepato-gastroenterologists manage prolonged PT/INR or severe thrombocytopenia before invasive procedures. METHODS: On May 2021, AISF members were sent a questionnaire addressing the PT/INR and platelet thresholds required before invasive procedures, the use of other markers of bleeding risk or other hemostatic treatments and the burden of pre-emptive plasma and platelet transfusions. RESULTS: Of 62 respondents, 94% and 100% use PT/INR and platelet count to assess bleeding risk, respectively. Only 37% and 32% require less conservative PT/INR or platelet counts thresholds for low-risk procedures, respectively. As for those applying single thresholds, 68% require PT/INR <1,5 and 86% require platelet counts ≥50 × 109/L. Half respondents use additional indicators of bleeding risk and 63% other hemostatic treatments. Low-risk procedures account for 70% of procedures, and for 50% and 59% of plasma and platelets units transfused, respectively. CONCLUSIONS: the survey indicates lack of compliance with guidelines that advise against plasma and platelet transfusions before invasive procedures and the need for prospective studies and inter-society consensus workshops.

ANEMIA: an expert consultation system.

Anemia is a knowledge-based consultation program for anemic states. It has been built using an artificial intelligence programming scheme, called EXPERT, which was developed at Rutgers University. At present, ANEMIA is able to provide assistance in the diagnosis and management of 64 disease entities. They include iron deficiency anemias, anemias due to chronic disorders, thalassemias, hemolytic anemias, arigenerative anemias, and a few other miscellaneous conditions. ANEMIA was tested against a data base of 220 retrospective and 100 new cases and the overall accuracy in the diagnostic performance was pretty good. Our intent is that ANEMIA ultimately will be able to serve as surrogate for the hematologist with the nonhematologist physician-user.

A performance evaluation of the expert system ANEMIA.

This paper reports the results of an evaluation study of the current level of performance given by ANEMIA, a knowledge-based consultation system addressing the clinical problem of managing anemic patients. ANEMIA was developed on a mainframe using the AI programming scheme EXPERT and then translated into a version running on a personal computer. At present the system is able to provide assistance in the diagnosis and management of 65 disease entities. After extensive local testing of accuracy, completeness, and consistency of the knowledge base included into ANEMIA, we designed a study to evaluate whether the system is able to appropriately mirror also the reasoning of well-known hematologists other than those who provided the knowledge. We were also interested in testing whether there were conflicting opinions among hematologists. Thus, we designed a validation study in which ANEMIA's performance could be compared with that of six hematologists and the interexpert consensus evaluated. ANEMIA's overall performance was judged acceptable in 87% (26/30) of the cases, while expert evaluators agreed with their colleagues in 90% (27/30) of them. A low interexpert consensus was found: considering the ratings given by different hematologists to the same ANEMIA performance, complete agreement occurred only 47% of the time.

Iron status in red cell pyruvate kinase deficiency: study of Italian cases.

We investigated the iron status of 33 pyruvate kinase (PK) deficient patients, most of the cases reported in Italy. Serum ferritin (SF) was higher than the upper limit of the range of matched controls in 15/25 (60%) non-transfused patients (median 228 micrograms/l, range 58-3160 v 43, 22-310). Liver siderosis and fibrosis were found in 8/9, and cirrhosis in two who died at age 39 and 42 of complications of iron overload. SF was independent of age, sex, or severity of haemolysis. The prevalence of HLA-A3 antigen in PK deficient patients was not significantly different from that of our healthy population (29.6% v 23%). The HLA-A3 positive, non-transfused patients had significantly higher SF values than the HLA-A3 negative ones (median 675 micrograms/l, range 340-3160 v 145, 58-400). A pedigree study of six high SF-probands indicated that iron overload has a multifactorial pathogenesis. In particular, the association of PK deficiency-induced haemolysis, splenectomy and an additional factor (heterozygosity for idiopathic haemochromatosis, ineffective erythropoiesis) leads to severe iron accumulation. We suggest that monitoring iron status would be useful in PK deficient patients, particularly in splenectomized and HLA-A3 positive ones, to identify those at risk of iron overload and prevent the clinical consequences of iron accumulation.

Sensitivity and predictive value of serum ferritin and free erythrocyte protoporphyrin for iron deficiency.

The sensitivity and predictive value of serum ferritin (SF) and free erythrocyte protoporphyrin (FEP) for iron deficiency (ID) was evaluated by studying 272 subjects with uncomplicated ID (174 with anemia and 98 without) in whom diagnosis was confirmed by the response to iron supplementation. Overall, the sensitivity, at 95% specificity, was 82% (79% in women, 94% in men) for SF and 61% (60% in women, 65% in men) for FEP. The sensitivity varied as a function of hemoglobin values, dropping from over 90% for both tests in the case of severe anemia, to approximately 70% for SF and less than 50% for FEP in the absence of anemia. The predictive value decreases more sharply for FEP than for SF with increasing hemoglobin levels. It is concluded that SF is preferable to FEP for the detection of ID, particularly in the absence of anemia. However, owing to the unsatisfactory predictive value at low prevalence, SF should be used as a screening test for ID without anemia only when the prevalence is at least 20%.

Relative iron deficiency in hereditary spherocytosis.

Seventy-three patients with hereditary spherocytosis (HS) (58 nonsplenectomized, 15 splenectomized) were studied to evaluate iron status and the adequacy of iron availability for erythropoiesis. Splenectomized patients, who had hemoglobin levels in the normal or upper normal range, had higher levels of serum iron, transferrin saturation, and serum ferritin than normal matched controls and normal zinc protoporphyrin (ZnPP) levels. On the contrary, nonsplenectomized patients presenting with mild to severe anemia had higher red cell ZnPP concentrations than both splenectomized subjects and matched normal controls. ZnPP in nonsplenectomized patients correlated inversely with Hb concentration, mean corpuscular volume (MCV), mean red cell hemoglobin concentration (MCHC), transferrin saturation, and serum iron, and directly with reticulocyte count. At multiple regression analysis only Hb concentration was a significant explanatory variable for high ZnPP. The authors conclude that a number of nonsplenectomized HS patients have relative iron deficiency primarily because of expansion of erythropoiesis caused by anemia.