# Platelet storage pool deficiency

Platelet storage pool deficiency is a family of clotting disorders characterized by deficient granules in platelets. Individuals with these disorders have too few or abnormally functioning alpha granules, delta granules, or both alpha and delta granules and are therefore unable to form effective clots, which leads to prolonged bleeding. Platelet storage pool deficiency can be acquired or inherited.

## Symptoms and signs

The symptoms individuals with platelet storage pool deficiency may experience include the following:
* Easy bruising
* Nose bleeds
* Bleeding from gums
* Heavy or prolonged menstrual bleeding (menorrhagia) or bleeding after childbirth
* Abnormal bleeding after surgery, circumcision, or dental work
Severity can vary widely from person to person, and individuals with platelet storage pool deficiency may not experience all of the above symptoms.

## Cause

Platelet storage pool deficiency can be acquired or inherited. Inheritance may be autosomal dominant or autosomal recessive, depending on the specific disorder.
Some of the causes of platelet storage pool deficiency when acquired are:
                        * Hairy-cell leukemia
                        * Cardiovascular bypass

## Mechanism

In terms of the pathophysiology of platelet storage pool deficiency one must consider several factors including the human body's normal function prior to such a deficiency, such as platelet alpha-granules one of three types of platelet secretory granule.
Platelet α–granules are important in platelet activity. α–granules connect with plasma membrane. This in turn increases the size of the platelet. Platelet α–granules have an important role in hemostasis as well as thrombosis. SNARE accessory proteins control the secretion of α–granule.

## Diagnosis

The diagnosis of this condition can be done via the following:
* Flow cytometry
* Bleeding time analysis
* Platelet aggregation function study:
Platelet aggregation function by disorders and agonists :
| | ADP | Epinephrine | Collagen | Ristocetin |
| P2Y receptor defect (including Clopidogrel) | Decreased | Normal | Normal | Normal |
| Adrenergic receptor defect | Normal | Decreased | Normal | Normal |
| Collagen receptor defect | Normal | Normal | Decreased or absent | Normal |
| Von Willebrand disease (except Type 2B) Bernard–Soulier syndrome | Normal | Normal | Normal | Decreased or absent |
| Glanzmann's thrombasthenia Afibrinogenemia | Decreased | Decreased | Decreased | Normal or decreased |
| Storage pool deficiency | Absent second wave | Absent second wave | Absent second wave | Partial |
| Aspirin or aspirin-like disorder | Absent second wave | Absent second wave | Absent | Normal |

### Types

This condition may involve the alpha granules or the dense granules. Some common inherited disorders associated with each include the following:
* Platelet alpha-granules
** Gray platelet syndrome
** Quebec platelet disorder
* Dense granules
** δ-Storage pool deficiency
** Hermansky–Pudlak syndrome
** Chédiak–Higashi syndrome

## Treatment

Platelet storage pool deficiency usually requires no daily treatment, although many individuals with heavy menstrual bleeding take hormonal contraceptives to reduce menstrual symptoms. However, management of uncontrolled bleeding consists of antifibrinolytic medications or transfusion of normal blood products. Additionally, caution should be taken with usage of NSAIDS, since they thin the blood and further impair clotting.