Concomitant Vitamin B1 and Vitamin B12 Deficiency Mimicking Thrombotic Thrombocytopenic Purpura

Abstract

Vitamin B12 deficiency-induced pseudo-thrombotic thrombocytopenic purpura (pseudo-TTP) is a rare condition. In reported literature, most cases were due to pernicious anemia (confirmed by the presence of anti-parietal cells or anti-intrinsic factor antibodies). Nutritional vitamin B12 deficiency causing pseudo-TTP is a much rarer entity. Differentiating thrombotic thrombocytopenic purpura (TTP) cases from pseudo-TTP (from any cause) should be done as soon as possible since the etiology, treatment, and outcome are different. Hematological findings from pseudo-TTP (when associated with vitamin B12 deficiency) respond to B12 replacement but do not respond to plasmapheresis. Neurological symptoms are one of the criteria for TTP, and altered mentation or psychosis in these cases is presumed secondary to either TTP or vitamin B12 deficiency. However, neurological symptoms are more characteristic of TTP rather than pseudo-TTP. In the rarer subsets of patients concerned with nutritional deficiency and neuropsychiatric symptoms, prompt consideration of concomitant vitamin B1 deficiency and Wernicke encephalopathy is essential. Immediate empiric treatment with high-dose IV thiamine should be started. If unrecognized and left untreated, thiamine deficiency can cause rapid progression to irreversible neurological symptoms, coma, and death, despite hematological improvement with B12 replacement. We report a rare case of concomitant vitamin B12 and vitamin B1 deficiency presenting with confusion, severe hemolytic anemia, acute renal failure, diarrhea, and thrombocytopenia mimicking TTP.

Pernicious Anemia Presenting as a Mimicker of Thrombotic Thrombocytopenic Purpura

“…Two additional cases were discovered in our review of prior case reports in which the patient did receive TPE. In one of the cases, the patient was found to have hemolytic anemia along with altered mentation resulting in a presumptive diagnosis of TTP [ 12 ]. It was later discovered, after initiating TPE, that he had nutritional deficiencies in both vitamin B12 and B1.…”

Adult Vitamin B12 Deficiency-Associated Pseudo-Thrombotic Microangiopathy: A Systematic Review of Case Reports

“…Of the 46 case reports, six mentioned nutritional deficiency as an etiology. Of note, the case reported by Ganipisetti et al also had concomitant thiamine deficiency [ 3 ], while the case reported by Ceuleers et al had concomitant folate deficiency [ 12 ]. Hussain et al reported metformin use as the etiology [ 28 ], and Ricci et al reported human immunodeficiency virus-associated loss of haptocorrin as the etiology [ 45 ].…”

“…This clinical combination of anemia with an elevated LDH, schistocytosis, and thrmobocytopenia closely mimics the presentation of TTP. Cobalamin-deficient thrombotic microangiopathy is a relatively rare disorder with a prevalence estimates as low as 0.6% to 2.5% of all vitamin B12 deficiency cases [ 3 ]. Due to its ambiguous presentation and comparative rarity, it is often misdiagnosed as TTP and treated inappropriately with plasmapheresis [ 4 ].…”

Role of the PLASMIC Score in the Management of Thrombotic Thrombocytopenic Purpura

“…Consequently, vitamin B12 replacement remains the treatment of such patients instead of therapeutic plasma exchange. Additionally, case reports have mentioned thiamine deficiency contributing to vitamin B12 deficiency causing pseudo-thrombotic microangiopathy [13].…”

“…However, our patient's labs did not align with these diagnostic criteria. Hence, with the help of a peripheral blood smear, the PLASMIC score can help us differentiate between pseudo-TMA and TTP [13]. One retrospective cohort study in a premier institute in the United States showed higher PLASMIC scores in the TTP cohort compared to the pseudo-TMA cohort (6.1 points out of a possible 7 vs. 4.9, p-value = 0.02) [14].…”