34 Low‐Volume Plasma Exchange and Low‐Dose Steroid to Treat 34 56 Secondary Hemophagocytic Lymphohistiocytosis: A Potential 56 78 Treatment for Severe COVID‐19? 78
9 Vijay Alexander1, Uday Zachariah1, Ashish Goel1, Subramani Kandasamy2, Binila Chacko2, John Victor Punitha3, Sukesh Nair4, Vinoi David5, 9 10 Savit Prabhu6, K. A. Balasubramanian6, Ian Mackie7, Elwyn Elias1,8, C. E. Eapen1 10
12 6The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India, 7Department of Research 12 13 Haematology, University College London, London, 8Liver Unit, University Hospitals Birmingham, Birmingham, United Kingdom 13
11 14 14
Departments of 1Hepatology, 4Transfusion Medicine and Immunohaematology and 5Nephrology, 2Division of Critical Care, 3Department of Medicine ‐ Medicine Unit I,
15 Abstract 15 16 16
17 Secondary hemophagocytic lymphohistiocytosis (sHLH) may be responsible for some of the deaths in adult patients with severe COVID‐19. 17 18 We present our experience of low‐volume plasma exchange (PLEX) with low‐dose steroid in the treatment of adult patients with sHLH and 18 19 acute liver failure caused by dengue virus and other nonviral triggers and discuss how this may be effective in the management of severe 19 20 COVID‐19. sHLH is poorly understood and without effective treatment. Endothelium of the capillaries of the lungs and kidneys and of liver 20 21 sinusoids does not express von Willebrand factor (VWF) in health and is where most macrophages are located. Plasma VWF levels are high 21 22 in sHLH and require clearance by macrophages, which when activated enlarge and likely block the lumen. Current histology studies neither 22
appreciate microcirculatory sludge nor display endothelial–macrophage interactions. We hypothesize that low‐volume PLEX and low‐dose
23 steroid may reverse sHLH and improve survival in severe COVID‐19 patients with acute lung injury. 23
24 Key words: Ameliorate macrophage activation, plasma exchange, steroid 24 25 25
26 26 27 27 28 28 29 29 30 30
￼ ￼ ￼ ￼
Address for correspondence: Dr. C. E. Eapen, Department of Hepatology, Christian Medical College, Vellore, Tamil Nadu, India. E‐Mail: firstname.lastname@example.org
31 Secondary HemopHagocytic LympHoHiStiocytoSiS in Severe covid-19 patientS 31
32 Macrophages, cells of the innate immune system, respond rapidly (within 20–30 min) once the host recognizes an invading 32 33 microbe by phagocytosis. However, uncontrolled macrophage activation//secondary hemophagocytic lymphohistiocytosis 33
34 (sHLH) commonly triggered by viruses can lead to cytokine storm, multi‐organ failure, and death. 34 35 35
36 Among hospitalized adult COVID‐19 patients, serum ferritin (a marker of macrophage activation) and interleukin‐6 (a 36 37 pro‐in ammatory cytokine) levels were signi cantly higher in nonsurvivors and increased with worsening illness. In view of 37 38 cytokine storm and sHLH, it has been suggested that severe COVID‐19 patients be screened for hyperin ammation (increasing 38 39 ferritin levels, decreasing platelet counts, and HScore [used to diagnose sHLH]) to consider immunosuppressive therapy. 39
40 sHLH pathophysiology is poorly understood and better insight into its mechanisms, and treatment may improve survival. 40 41 41 42 42 43 43
44 44 45 This is an open access journal, and ar cles are distributed under the terms of the Crea ve 45 46 Commons A ribu on‐NonCommercial‐ShareAlike 4.0 License, which allows others to 46
remix, tweak, and build upon the work non‐commercially, as long as appropriate credit
47 is given and the new crea ons are licensed under the iden cal terms. 47
48 For reprints contact: email@example.com 48 49 49
50 50 51 51 52 52
Date of Submission: 04‐Apr‐2020 Date of Review: 06‐Apr‐2020 Date of Acceptance: 07‐Apr‐2020 Date of Web Publication: ***
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How to cite this article: Alexander V, Zachariah U, Goel A, Kandasamy S, Chacko B, Punitha JV, et al. Low‐volume plasma exchange and low‐dose steroid to treat secondary hemophagocytic lymphohistiocytosis: A potential treatment for severe COVID‐19? Curr Med Issues 2020;18:XX‐XX.
1 our HypotHeSiS
liver failure: 24 patients) tested, all had markedly raised serum 1 sCD163 (marker of macrophage activation) levels and this 2 correlated with disease severity and in‐hospital mortality. 3
Of 21 patients with very severe alcoholic hepatitis (median 45 model for end‐stage liver disease [MELD] score of 32 [28–42]
and median discriminant function score of 91.8 [70.7–159.6]) 6 treated by this protocol, 13 (62%) survived without liver 7 transplantation. Of 13 patients with idiosyncratic drug‐induced 8 liver injury who met criteria for liver transplantation treated by 9 this protocol, six patients survived without liver transplantation. 10 Of ten patients with rodenticidal hepatotoxicity who met the 11 listing criteria for liver transplantation (median MELD score 12 39 [36–40]) treated by this protocol, five patients (50%) 13 survived without liver transplantation. 14
Improved survival has been reported with low‐volume of 15 plasma exchanged in acute‐on chronic liver failure patients 16 with milder grade of disease severity. 17
18 tHe poSSibLe Link between activation of 19
Alexander, et al.: Plasma exchange and steroid to treat secondary hemophagocytic lymphohistiocytosis
. 2 Low‐volume PLEX and low‐dose steroid may improve
. 3 survival in patients with sHLH and acute lung/liver injury by
45 ameliorating macrophage overactivation. We postulate that
this treatment may improve survival in severe COVID‐19. 7 Support for tHe HypotHeSiS
8 We present our experience using a low‐volume PLEX and
. 9 low‐dose steroid protocol [Supplementary Material] to treat
. 10 patients with sHLH and acute liver failure due to dengue
. 11 virus and other nonviral triggers. Data from a prospectively
. 12 maintained database of patients with acute liver failure treated
. 13 by this protocol in our department were retrospectively
. 14 analyzed for this purpose, after obtaining approval from our
. 15 institutional review board and ethics committee. We discuss the
. 16 link between activation of endothelium and of macrophages in
. 17 sHLH. Endothelium of the capillaries of the lungs and kidneys
. 18 and of the liver sinusoids does not express von Willebrand
. 19 factor (VWF) in health and is where most macrophages
. 20 are located. Plasma VWF levels are high in sHLH and require
. 21 clearance by macrophages, which when activated enlarge and
. 22 likely impede microcirculatory perfusion in these organs. The
. 23 similarities between sHLH and associated organ failure in
. 24 severe COVID‐19 and viral (dengue)/nonviral triggers and
. 25 its implications are discussed.
endotHeLium and of macropHageS in Secondary 20 HemopHagocytic LympHoHiStiocytoSiS 21
. 26 our preLiminary experience witH Low-voLume
. 27 pLaSma excHange and Low-doSe Steroid to treat
Raised levels of the plasma VWF (a platelet adhesive protein 26 released from endothelium), low levels of a disintegrin and 27 metalloproteinase with a thrombospondin type 1 motif, 28 member 13 (ADAMTS13), an enzyme which cleaves VWF, 29 and thrombocytopenia are recognized in viral infections such as 30 dengue. VWF‐rich platelet plugs may block microcirculation 31 in acute in ammatory syndromes – termed as secondary 32 thrombotic microangiopathies; reduced microcirculatory 33 perfusion of vital organs is recognized as functional organ 34 failure by a clinician at the bedside. 35
29 dengue-induced Secondary HemopHagocytic
30 LympHoHiStiocytoSiS and acute Liver faiLure
. 31 Of three patients with dengue‐induced sHLH, acute liver
. 32 failure, and multi‐organ failure, treated with this protocol,
. 33 two patients who did not require mechanical ventilation had
. 34 reduction in sequential organ failure assessment (SOFA)
. 35 scores and hyperin ammation and survived [Table 1].
37 our preLiminary experience witH Low-voLume 38
. 39 pLaSma excHange and Low-doSe Steroid in
. 40 nonviraL acute Liver injury/faiLure
. 41 Alcohol, drugs, and toxins can also trigger macrophage
. 42 overactivation, and our preliminary experience with this
. 43 treatment protocol in acute liver injury/failure or acute‐on
chronic liver failure is promising. Of our rst 100 patients,
. 44 72 were treated in the high‐dependency unit and 28 in the
. 45 intensive care unit; 51 had acute liver injury/failure and
. 46 38 had acute‐on chronic liver failure. These 100 patients
. 47 underwent a median of three (range 2–5) sessions of PLEX,
. 48 and 1·5 (0·5–2) litres of plasma was exchanged per session
. 49 with fresh frozen plasma. Etiologies for liver disease
. 50 included alcohol (24 patients), phosphorus poisoning (18),
. 51 and idiosyncratic drug‐induced liver injury (16). Of
. 52 39 patients (acute liver injury/failure: 15, and acute‐on chronic
Endothelial cells lining the capillaries in the lungs and renal 36 glomeruli and sinusoids in the liver do not express VWF 37 in health. These “VWF‐free” zones are narrow (diameter of 38 the lung capillaries is 6.3 μm and of the liver sinusoids is 39 9–10 μm). VWF‐rich microthrombi were noted at autopsy 40 in children with reduced ADAMTS13 levels, multi‐organ 41 failure, and thrombocytopenia. In a prospective multicenter 42 trial, PLEX led to resolution of organ dysfunction and better 43 28‐day survival in children with multi‐organ failure and thrombocytopenia. 44
2 ￼ ￼Current Medical Issues ¦ Volume 18 ¦ Issue 2 ¦ April‐June 2020
22 The change in terminology from reticuloendothelial system to 23 mononuclear phagocyte system suggests close link between 24 endothelium and macrophages. 25
Animals (foals) dying of sepsis have increased lung 45 inflammation, increased VWF expression in the lung 46 capillaries, as well as increase in pulmonary intravascular 47 macrophages and VWF positivity demonstrated on the 48 macrophage surface. VWF is removed from the circulation 49 by macrophages and hepatocytes.[20,21] While macrophages are 50 present in all tissues, they are predominantly located in the 51 liver sinusoids (called Kupffer cells) and lung capillaries. 52
Alexander, et al.: Plasma exchange and steroid to treat secondary hemophagocytic lymphohistiocytosis 11
Table 1: Low‐volume plasma exchange and low‐dose steroid to treat dengue‐induced secondary hemophagocytic lymphohistiocytosis, acute liver failure, and multi‐organ failure
. 6 SOFA score 
. 7 Organ systems which
. 8 failed
. 10 Platelets (×109/L )
. 11 AST (U/L)
. 12 ALT (U/L)
. 13 Bilirubin (mg/dL)
. 14 PT/INR
. 15 MELD score
. 16 PaO2 (mmHg)
. 17 FiO2 (%)
. 18 SpO2 (%)
. 19 PF ratio
. 20 SF ratio
. 21 VWF Ag (IU/dL)
. 22 Ferritin (ng/mL)
. 23 sCD25 (pg/mL)
. 24 Highest HScore*
. 25 Dengue
. 26 Serology
. 27 Type of infection
. 28 PLEX
. 29 Number of sessions
. 30 Plasma volume exchanged
. 31 Prednisolone tablet
. 32 Respiratory support
. 33 Outcome
. 34 *Highest HScore36 was calculated using the most abnormal result when that parameter was tested anytime during hospital stay. (Note: Patient No. 2 34
. 35 had persistent fever ‐ hemophagocytosis was noted on bone marrow examination on day 15). Empiric antibiotics used: Patient No. 1 (azithromycin 35
. 36 from days 1 to 3, meropenem from days 1 to 7); Patient No. 2 (doxycycline on day 1, cefoperazone‐sulbactam from days 2 to 8, meropenem 36
. 37 from days 9 to 17); Patient No. 3 (days 1‐7: doxycycline, days 2‐4: cefoperazone‐sulbactam, days 5‐7: meropenem, day 7: colistin). Interval from 37
. 38 symptom onset to hospital admission was 7, 10, and 8 days in Patient No. 1, 2, and 3, respectively. Blood cultures done on separate days (5 times in 38
Patient No. 1, 6 times in Patient No. 2, and 3 times in Patient No. 3) were negative. Normal values for plasma VWF antigen: 50‐100 IU/dL; for serum
. 39 ferritin: 20‐320 ng/mL for males, 10‐290 ng/mL in females <50 years of age and for serum CD25: 1555‐10,800 pg/mL. Organ system failure 39
. 40 defined as per SOFA score. SOFA: Sequential organ failure assessment score, AST: Aspartate aminotransferase, ALT: Alanine aminotransferase, 40
Patient 1: 28 years/male Patient 2: 26 years/male Patient 3: 38 years/female 34 Day 1 Day 3 Day 7 Day 1 Day 3 Day 7 Day 1 Day 3 Day 7 5 11 9 3 8 6 4 12 12 16 6
Liver, CNS, Liver, Resp, Resp, Coag Coag
￼ ￼ ￼ ￼ ￼ ￼ ￼ ￼ ￼ ￼ ￼ ￼ ￼
11 9779 1838 3.07 1.9 20 59 40
44 2296 760 2.93 1.68
295 22,570 3136 64 128 56 45 11
94 95 147 177 235 237 644.8 394.1
132764 61428 >14000
95999998 ND ND ND ND
330 285 858.2 960.3 ND 571
194 20 459.9 21 358.8 22
NS1, IgM, IgG+ive Early primary
1 litre each on day 2, 3, 4
NS1, IgM, IgG+ive Early primary
25 IgM+ive; NS1, IgG ‐ ive 26
10 mg/day from days 2 to 6 Noninvasive ventilation Alive
20 mg/day from days 4 to 7 31 Mechanical ventilation 32 Taken home in terminal condition on Day 7 33
Liver, CNS, Liver, CVS, 7 Resp, Resp, CNS, 8 Coag Coag 9
229 3250 870 54 345 193 69 12
Liver, Liver, Liver, CNS, Coag CNS, Coag
10519 70 190 79 66 21 10
1.95 1.30 4.54 4.41
11.2 14.92 14.08 13 4.57 3.33 2.3 14 333532 15 895964 16 303550 17 99 100 97 18
1.07 2.65 1.83 1.09 161019 19 12 71NDND ND ND 402121 21 21
471 551.7 13149.5
471 273.5 5658.5 >14000 227
466 244.8 1469
1.2 litre on day 2, 3; 2.4 litre on day 4, 5
10 mg/day from days 2 to 8 None
Primary 27 28
. 43 antigen, sCD 25: Soluble cluster of differentiation 25, ND: Not done, PLEX: Plasma exchange, CNS: Central nervous system, Resp: Respiratory 43
. 44 system, Coag: Coagulation system, CVS: Cardiovascular system.
. 45 It seems important to keep these narrow low‐pressure
. 46 “VWF‐free” traffic zones patent (i.e., avoid VWF‐rich
. 47 platelet microthrombi to form), to allow free ow of traf c
. 48 (blood ow) through the capillaries of the lungs and kidneys
. 49 and sinusoids in the liver. These same narrow traf c zones in
. 50 the liver and lungs provide “parking slots” for macrophages
. 51 and may contribute to lumen narrowing as macrophages get
. 52 activated in sHLH.
Current Medical Issues ¦ Volume 18 ¦ Issue 2 ¦ April‐June 2020 ￼ ￼3
Liver, CNS, Coag
3 29 1.2 litre on days 5, 6, 7 30
41 PT/INR: Prothrombin time/international normalized ratio, MELD: Model for end‐stage liver disease, PaO : Partial pressure of oxygen, FiO : Fraction 22
41 42 of inspired oxygen, SpO2: Peripheral capillary oxygen saturation, PF ratio: PaO2/FiO2 ratio, SF ratio: SpO2/FiO2 ratio, VWF Ag: von Willebrand factor 42
44 HigH von wiLLebrand factor LeveLS in 45
microcircuLation: reLevance of coiLed and 46 47
StretcHed-out von wiLLebrand factor formS 48
VWF molecules released from the endothelial cells travel in 49 the blood stream mainly as coiled forms; hence, the binding 50 sites for platelets and ADAMTS13 are less exposed. When 51 VWF tethered to subendothelial collagen (at site of a vessel 52
Alexander, et al.: Plasma exchange and steroid to treat secondary hemophagocytic lymphohistiocytosis
. 1 wall breach) is stretched out by shear stress of owing blood,
. 2 it exposes its platelet binding site. VWF also carries factor
. 3 VIII (a coagulation factor). Thus, damage to the vessel wall
. 4 localizes platelets and VWF (and factor VIII).
. 5 What are the consequences of increased endothelial VWF
. 6 expression and of increased VWF levels in microcirculation?
. 7 In health, high molecular weight VWF multimers
. 8 (5000–10,000 kDa) comprise the main form of VWF in
. 9 circulation. In viral sHLH, it is likely that large‐coiled VWF
1 2 3 4 5 6 7
. 10 may sludge capillaries/liver sinusoids. The stretched‐out VWF
. 11 due to increased shear stress in arterioles attracts more platelets, recognized by the clinician as thrombocytopenia. Microthrombi
. 12 in the areas of infection may be an innate immune response to
Figure 1: The flow of traffic at 9 am (a) in front of Christian 8 Medical College, Vellore hospital, resembles “traffic jam in the 9 narrow lanes” in liver sinusoids/lung capillaries in secondary 10 hemophagocytic lymphohistiocytosis while (b) normal traffic flow at 11 5 pm. In health, the lumen of lung capillaries and of liver sinusoids
13 contain infection and is termed immunothrombosis. 14
should contain 50% of blood cells and 50% of plasma; in secondary 12 hemophagocytic lymphohistiocytosis, the lumen is drastically narrowed 13 by hyperinflammation and leads to reduced organ perfusion and organ 14 failure. Credits: Dr. Kirti Anna Koikkara. 15
in the endothelial lining as well as arrival of innate immune 16 cells (such as monocytes and neutrophils) and of large‐sized 17 proteins such as VWF (for clearance by macrophages) 18 will further narrow the lumen in the narrow, low‐pressure 19 “VWF‐free zones” in vital organs. What are the possible 20 consequences of acute obstruction to ow in liver sinusoids 21 and lung/renal capillaries? It is interesting to note that a 22 physiological PLEX occurs through fenestrated endothelial 23 cells lining the hepatic sinusoids in health. Acute reduction 24 in microcirculatory perfusion in a vital organ will lead to acute 25 organ dysfunction, and when reduction in perfusion crosses a 26 critical threshold, tissue necrosis and organ failure are likely. 27
Why is this “traf c jam” not well recognized on histology 28 studies? 29
Antemortem tissue biopsies do not retain the free‐ owing 30 intravascular contents; hence, microcirculatory sludge 31 in any organ is not appreciated in these biopsies. Newer 32 techniques are needed to study this. It is possible that 33 postmortem studies, i.e. after blood ow in circulation has 34 ceased, may appreciate the microcirculatory sludge better. 35 Indeed, postmortem studies in 50 acute liver failure patients 36 demonstrated congestion of capillaries as the most common 37 histopathological nding in lungs (in 50% of patients), in 38 kidneys (in 58%), and in liver (in 40%). This was associated 39 with hepatic necrosis (in 62% of patients) and acute renal 40 tubular necrosis (in 44%). 41
42 primary verSuS Secondary HemopHagocytic 43
16 pLaSma excHange protocoL may ameLiorate
. 17 macropHage activation and improve muLti-organ
. 18 dySfunction and SurvivaL in patientS witH acute
19 Liver injury/faiLure
. 20 High‐volume PLEX (8–12 litres of plasma exchanged with
. 21 fresh frozen plasma daily for 3 days) attenuated innate
. 22 immune activation, ameliorated multi‐organ dysfunction,
. 23 and improved liver transplant‐free survival by about 10% in
. 24 acute liver failure. As this survival bene t is not seen with
. 25 renal replacement therapy, we postulate that molecules too
. 26 large (>60 kDa) to be removed by dialysis may be removed
. 27 by PLEX in these patients. VWF is the largest known protein
. 28 in the normal human plasma. High molecular weight VWF
. 29 multimers (up to 10,000 kDa) will not be removed by dialysis.
. 30 Raised plasma VWF levels accurately predicted in‐hospital
. 31 mortality in 24 patients with acute hepatotoxicity (20 patients
. 32 had acute liver injury, while three had acute liver, failure)
. 33 and in 50 patients with acute‐on chronic liver failure. Thus,
. 34 VWF pheresis may explain the survival bene t of PLEX in
. 35 patients with liver failure. VWF reduction is being explored
. 36 to treat acute liver failure syndromes.[26,29,30] In patients with
. 37 raised plasma VWF levels, PLEX reduces plasma VWF levels
. 38 by two mechanisms: by removing VWF in the pheresed plasma
. 39 and by supplementing ADAMTS13 (a VWF cleaving protease)
. 40 in the form of replaced fresh frozen plasma.
. 41 The three dengue‐induced sHLH and acute liver failure patients
. 42 in our report [Table 1] had raised plasma VWF levels (3.7–
. 43 5.7‐fold above upper limit of normal). As VWF is cleared by
. 44 macrophages, we postulate that the increased VWF load in
. 45 circulation may contribute to continued macrophage activation.
. 46 We hypothesize that PLEX reduces the raised plasma VWF
. 47 load, which in turn may ameliorate macrophage overactivation
in sHLH patients.
LympHoHiStiocytoSiS: reLevance to covid-19 44 45
49 acute faiLure of Liver/LungS may be due to a
Macrophage activation is kept in check by natural killer cells 46 and/or cytotoxic T‐lymphocytes. The latter cells may either 47 create a hole on the macrophage surface (via perforins) or
encourage macrophage death (through granules with potent 48 cytolytic enzymes [such as granulysin] inserted into the 49 macrophage). Absent/reduced natural killer cell/cytotoxic 50 T‐cell function leading to uncontrolled macrophage activation 51 is termed primary HLH. 52
50 “traffic jam” in itS microcircuLation [figure 1] 51
52 An acute increase in the number and size of macrophages
4 ￼ ￼Current Medical Issues ¦ Volume 18 ¦ Issue 2 ¦ April‐June 2020
Alexander, et al.: Plasma exchange and steroid to treat secondary hemophagocytic lymphohistiocytosis
. 1 In contrast to primary HLH, in sHLH, the natural killer
. 2 cells/cytotoxic T‐cells may get overactivated, in an attempt
. 3 to control the macrophage overactivation. A patient who died
. 4 of COVID‐19 had high concentrations of cytotoxic granules
. 5 in the peripheral blood CD8 T‐cells (32% cells were perforin
. 6 positive, 64% were granulysin positive, and 31% were positive
. 7 for both). It is possible that this T‐cell overactivation re ects
. 8 the natural killer/cytotoxic T‐cells machinery, attempting to
. 9 control the macrophage overactivation. The collateral damage
. 10 by this overactive T‐cell response may add to the lung injury.
. 11 How doeS treatment of dengue-induced acute
While our report of viral (dengue)‐induced sHLH and acute 2 liver failure is limited to three patients [Table 1], it provides a 3 mechanistic explanation why lung and other multi‐organ failure 4 occur in COVID‐19 patients. Our preliminary experience with 5 dengue‐induced sHLH does not prove that low‐volume PLEX 6 and low‐dose steroid ameliorate macrophage overactivation 7 and improve survival in viral sHLH. However, our experience 8 with more number of patients with acute liver injury/failure 9 due to other causes (who also have sHLH) treated by this 10 protocol is encouraging. 11
Plasma obtained from healthy unselected donors from the 12 blood bank was used in PLEX treatment of our three dengue 13 patients. We did neither use convalescent plasma from 14 individuals who recovered recently from dengue nor were 15 dengue antibodies tested in the donor plasma. 16
Unlike dengue which is arthropod borne, SARS‐CoV2 which 17 causes COVID‐19 is highly contagious. Hence, healthcare 18 workers need to take appropriate personal protective measures 19 when managing critically ill COVID‐19 patients. 20
12 Liver faiLure Have reLevance to acute Lung 13
. 14 injury in Severe covid-19?
. 15 Hyperferritinemia in severe dengue [Table 1] and severe
. 16 COVID‐19 patients and raised serum sCD 25 levels
. 17 and HScore >169 in dengue patients suggest macrophage
. 18 activation syndrome/sHLH [Table 1].
. 19 Postmortem lung biopsies indicate sHLH in patients
. 20 with severe acute respiratory syndrome (SARS) due to
. 21 SARS‐associated coronavirus and avian in uenza A (H5N1)
. 22 infection (marked increase in macrophages in alveoli and
. 23 in interstitium and hemophagocytosis[37,38]). Fibrin thrombi
. 24 in the pulmonary vessels were also noted in one patient.
. 25 Overactivated CD8 T‐cells in a severe COVID‐19 patient
. 26 suggest the expected cytotoxic T‐cell response to macrophage
. 27 overactivation in sHLH.
. 28 Raised VWF load in the plasma may trigger continued
. 29 macrophage activation as macrophages work to clear the
. 30 VWF load. Macrophage activation triggers cytokine storm.
. 31 “Traf c jam” in the liver sinusoids (in dengue‐induced acute
. 32 liver failure) and in the lung capillaries (in COVID‐19 patients)
. 33 and in other vital organs will lead to reduced perfusion and
. 34 failure of these organs.
. 35 Some pointS to HigHLigHt in our treatment
Due to concern that steroid may delay viral clearance, it 21
COVID‐19 patients with less severe acute lung injury (organ 34 dysfunction, before onset of organ failure) need to be selected 35 for the treatment with low‐volume PLEX and low‐dose steroid. 36 The window for this therapeutic intervention is likely to be 37 narrow and needs to be de ned in appropriately designed 38 studies. 39
38 1. 39
40 2. 41
. 44 3.
. 45 4.
50 5. 51
Outcomes are best, when treatment is implemented at the stage of acute liver injury, rather than acute liver failure We start low‐dose steroid before starting PLEX and continue for 1–4 weeks after. This strategy appears to ameliorate the secondary macrophage activation syndrome/sHLH
Low volume of exchanged plasma appears effective The replacement uid is fresh frozen plasma from healthy donors at 1:1 volume (so that the pheresed plasma does not render the patient immune depleted and more prone to sepsis. In addition, ADAMTS13 in the infused fresh frozen plasma has a VWF lowering effect)
We avoid isolated platelet transfusion in patients with thrombocytopenia in the setting of activated endothelium (re ected by raised plasma VWF levels).
impLicationS and unknownS of tHe HypotHeSiS 1
has been suggested that steroid should not be routinely 22
used in patients with COVID‐19 and acute lung injury. 23
The risks and bene ts of low‐dose steroid advocated in our 24
treatment protocol need to be tested in clinical trials of severe 25
COVID‐19 patients. 26 27
How to teSt tHe HypotHeSiS 28
Markers of activation of macrophages (such as raised serum 29 ferritin levels and raised serum sCD163 levels) and of 30 endothelium (such as thrombocytopenia and raised plasma 31 VWF levels) need to be studied in COVID‐19 patients across 32 a spectrum of disease severity. 33
We gratefully acknowledge the technical inputs and support 41
from Dr. Shibu Jacob, Nephrology Department, and 42
Dr. Dolly Daniel and Dr. Joy Mammen, Transfusion Medicine 43
and Immunohaematology Department, Christian Medical 44 45 College Hospital, Vellore, India, for providing PLEX therapy 46
for acutely ill patients in liver failure. 47 Financial support and sponsorship 48
There are no con icts of interest. 51 52
Conflicts of interest
Current Medical Issues ¦ Volume 18 ¦ Issue 2 ¦ April‐June 2020 ￼ ￼5
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2 1. 3
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Low‐volume plasma exchange (PLEX) and low‐dose steroid to treat acute liver injury/failure OR acute‐on chronic liver failure: The Vellore Protocol
1. Acute liver injury/failure±other vital organ injury/failure
2. Secondary hemophagocytic lymphohistiocytosis (HLH) (serum ferritin≥500 ng/mL) 3. Endothelial activation (raised plasma von Willebrand factor [VWF] levels).
1. Recent major bleed (gastrointestinal, intracranial, pulmonary, intravitreal, etc., in the last 2 weeks. As VWF is a blood clotting protein, we are concerned about precipitating further bleeding by VWF depletion)
2. Ongoing sepsis
3. Hemodynamic instability after appropriate resuscitation and vasopressor support of>0.5 mcg/kg/min of noradrenaline or a
second vasoactive drug to maintain a mean arterial pressure of 65 mmHg.
1. Patients are admitted to a monitored setting (high‐dependency unit/ITU)
2. Obtain patient/next of kin consent after counseling about all other treatment options
3. Femoral vein is our preferred access for PLEX port insertion under ultrasound guidance. This access is exclusively for
PLEX and not used for any other reason (e.g. obtaining blood samples, administering medicines). We do not use prophylactic
platelet transfusion for line insertion
4. We avoid sedation (to reduce need for mechanical ventilation and risk of precipitating encephalopathy). Patients at risk of
aspiration or who develop respiratory failure are intubated on a case‐by‐case basis
5. We do not give prophylactic platelet transfusions. In case of need for platelet transfusion to cover for an invasive procedure,
we give fresh frozen plasma infusions (to supplement ADAMTS13) before giving platelet concentrates
6. It is preferable to avoid invasive diagnostic tests, until this treatment is completed
7. We give empiric antibiotic after blood culture
8. Tablet Prednisolone 10 mg or equivalent is started as soon as decision to PLEX taken and continued for at least 1 week
after stopping PLEX. Longer duration (up to 4 weeks) of steroids, if needed, may be given after reassessing the patient’s
9. Plasma volume is estimated by Kaplan method [0.065 × weight (kg)] × (1 − hematocrit). We target 50% of plasma volume
to be exchanged per the PLEX session. In case of major bleed (2–4 weeks ago)/treated sepsis/signi cant hemodynamic
instability, 25% of plasma volume is exchanged
10. Thereplacement uidisfreshfrozenplasmaat1:1volume(sothatthepheresedplasmadoesnotrenderthepatientimmune
depleted and more prone to sepsis. In addition, ADAMTS13 in the infused fresh frozen plasma has a VWF‐lowering effect). 11. Centrifugal‐type PLEX is preferred to membrane‐type PLEX
12. PLEX is done daily and three sessions targeted; the decision on performing PLEX is to be reviewed each day; the total
number of sessions of PLEX is decided based on tolerability/patient’s clinical condition. During PLEX, strict asepsis/avoid
hemodynamic instability/give adequate calcium supplementation. Remove port as soon as need for PLEX is over
13. Infection surveillance: We do daily surveillance blood culture on days of PLEX. In case of bacteremia/clinical signs of
worsening sepsis while on PLEX, withhold/discontinue PLEX until sepsis is controlled.
14. N‐Acetyl cysteine (as a VWF‐lowering measure, oral or intravenous) and oral zinc (aimed to reduce gut permeability)
are also given for 2–4 weeks
15. Organ‐speci c standard of care for critically ill patient to continue.
References (for Supplementary Material–PLEX Protocol)
1. La Rosée P, Horne A, Hines M, von Bahr Greenwood T, Machowicz R, Berliner N, et al. Recommendations for the management of hemophagocytic lymphohistiocytosis in adults. Blood 2019;133:2465‐77.
2. Patel L, Jacob S, Mathews N, Mammen J, Nair SC, Vijayalekshmi B, et al. Plasma exchange therapy in liver failure: Femoral port insertion may be preferable Indian J Gastroenterol 2018;37(Suppl 1):A79 Abstract # 259.
3. Kaplan AA. A simple and accurate method for prescribing plasma exchange. ASAIO Trans 1990;36:M597‐9.
4. Chen J, Reheman A, Gushiken FC, Nolasco L, Fu X, Moake JL, et al. N‐acetylcysteine reduces the size and activity of von
Willebrand factor in human plasma and mice. J Clin Invest 2011;121:593‐603.